Treatment Patterns Research Articles

Psychiatric diagnoses are common after liver transplantation and associated with increased healthcare utilization and patient financial burden.

Psychiatric disorders after liver transplantation (LT) are associated with worse patient and graft outcomes, which may be amplified by inadequate treatment. We aimed to characterize the burden of psychiatric disorders, treatment patterns, and associated financial burden among LT recipients (LTRs). IQVIA PharMetrics® Plus for Academics-a large health plan claims database representative of the commercially insured U.S. population-was used to identify psychiatric diagnoses among adult LTRs and assess treatment. Multivariable logistic regression analysis identified factors associated with post-LT psychiatric diagnoses and receipt of pharmacotherapy. Patient financial liability was estimated using adjudicated medical/pharmacy claims for LTRs with and without psychiatric diagnoses. Post-LT psychiatric diagnoses were identified in 395 (29.5%) of 1,338 LTRs, of which 106 (26.8%) were incident cases. Treatment varied, with 67.3% receiving pharmacotherapy, 32.1% psychotherapy, 21.0% combination therapy, and 21.5% no treatment. Among 340 LTRs on psychotropic medications before transplant, 24% did not continue them post-LT. Post-LT psychiatric diagnoses were independently associated with female sex, alcohol-associated liver disease (ALD), prolonged LT hospitalization (>2 weeks), and pre-LT psychiatric diagnosis. Incident psychiatric diagnoses were associated with female sex, ALD, and prolonged LT hospitalization. Patients with a post-LT psychiatric diagnosis had higher rates of hospitalization (89.6% vs 81.5%, p<0.001) and financial liability (median $5.5K vs $4.6K USD, p=0.006). Having a psychiatric diagnosis post-LT was independently associated with experiencing high financial liability >$5K. Over 1 in 4 LTRs had a psychiatric diagnosis in a large national cohort, yet nearly a quarter received no treatment. LTRs with psychiatric diagnoses experienced increased healthcare utilization and higher financial liability. Sociodemographic and clinical risk factors could inform high-risk subgroups who may benefit from screening and mitigation strategies.

Treatment Patterns and Clinical Outcomes of Patients with Moderate to Severe Acute Graft-Versus-Host Disease: A Multicenter Chart Review Study

Treatment Patterns and Clinical Outcomes of Patients with Moderate to Severe Acute Graft-Versus-Host Disease: A Multicenter Chart Review Study

Treatment of Stress Urinary Incontinence: Does Race Matter?

The importance of this study was to examine treatment patterns and surgical complications for stress urinary incontinence (SUI). The aim of this study was to describe the treatment of SUI and associated complications in a racially and ethnically diverse population. This was a retrospective cohort study of patients with a new diagnosis of SUI. We identified patients who received treatment with a pessary, pelvic floor physical therapy, or surgery. Surgical complications were abstracted. Logistic regression was used to examine the association between race/ethnicity and treatment, as well as surgical complications. A total of 67,187 patients with a new diagnosis of SUI were included. The population was predominately Hispanic (47.5%) followed by White, Asian, Black, Native Hawaiian/Pacific Islander, and American Indian/Alaska Native. Comparing no treatment to any treatment, all racial/ethnic groups, except American Indian/Alaska Native, had decreased odds of receiving treatment compared with White women. Hispanic and Native Hawaiian/Pacific Islander women had increased odds of referral for pelvic floor physical therapy compared with White women. All racial/ethnic groups, except for American Indian/Alaska Native women, had decreased odds of receiving a sling procedure compared with White women. When these racial/ethnic minority groups did receive treatment, it was more likely to be conservative treatment compared with White women. There were no significant differences in individual surgical complications. Racial minority women were 20-50% less likely to undergo a sling procedure, commonly posited as the gold standard surgical treatment. Racial minority women were 40-100% more likely to receive conservative management and 20-50% less likely to receive any treatment compared with White women.

Treatment patterns and clinical outcomes in patients with metastatic triple-negative breast cancer: a large-scale data analysis using the Japanese claims database.

This study evaluated treatment patterns and clinical outcomes among patients with metastatic triple-negative breast cancer (mTNBC) in real-world clinical settings in Japan. The treatment patterns, time to next treatment or death (TTNTD), time to treatment discontinuation, adverse events of interest, and medical costs of treating patients with mTNBC in first-, second-, and third-line settings were investigated using data of patients meeting the inclusion criteria between January 2017 and March 2022 in a Japanese medical claims database. The treatment regimens for mTNBC were defined according to the Japanese Breast Cancer Society Clinical Practice Guidelines. In this study, 2236 patients with mTNBC (median age 66.0years; 99.8% female) were included in the first-line cohort. Of these, 46.6% and 20.8% were included in the second- and third-line cohorts, respectively. The two most frequently used treatments were capecitabine (19.1%) and S-1 (tegafur-gimeracil-oteracil) (14.5%) in the first-line cohort, eribulin (18.3%) and bevacizumab/paclitaxel (14.4%) in the second-line cohort, and eribulin (19.4%) and bevacizumab/paclitaxel (17.5%) in the third-line cohort. The TTNTD shortened as the line of therapy progressed (median 8.0, 6.5, and 5.2months for the first-, second-, and third-line treatments, respectively). Nausea/vomiting and neutropenia/leukopenia occurred in 62.8% and 18.3% of all patients, respectively. The medical total costs per day were 6.7, 10.2, and 12.9 thousand yen during the first-/second-/third-line treatments, respectively. This study provides insight into current treatment patterns for mTNBC in Japan. The cost-benefit balance worsens with later-line treatment and a high unmet need for mTNBC drug treatment remains.

Real-World Treatment Patterns, Clinical Outcomes, and Symptom Burden in Patients With Psoriatic Arthritis Prescribed Ixekizumab in the United States.

The objective of this study was to describe the real-world characteristics and clinical status of patients with psoriatic arthritis (PsA) currently prescribed ixekizumab. Data were drawn from the Adelphi PsA Plus Disease Specific Programme (DSP), a cross-sectional survey conducted in the United States between September 2021 and March 2022. Rheumatologists provided data for their next five consulting patients currently receiving ixekizumab, including demographic and clinical characteristics, disease severity, treatment history, reasons for treatment choice, satisfaction with current treatment, and current and historic symptom burden. Patients voluntarily completed questionnaires, providing perceptional data on symptom burden and satisfaction with current treatment. Overall, 68 rheumatologists provided data on 275 patients with PsA, 90 of whom completed the voluntary questionnaire. Patients had been prescribed ixekizumab for a mean of 11.7 (SD 10.6) months. Clinical characteristics, disease severity, and symptom burden of patients with PsA improved significantly from ixekizumab initiation to the most recent consultation, including symptom burden, tender and swollen joint counts, and body surface area affected by psoriasis (all P < 0.001). Both rheumatologists and patients were satisfied with ixekizumab treatment and reported improvements in pain and fatigue. Improvements were noted after more than three months of ixekizumab treatment duration and regardless of whether the patients had prior exposure to an advanced therapy or were treatment naïve. Our results indicate that ixekizumab was efficacious in the treatment of PsA in real-world clinical practice, complementing efficacy data from randomized controlled clinical trials. The results of this study may assist rheumatologists and their patients in making informed treatment choices.

Mesenteric Ischemia after Cardiac Surgery.

Mesenteric ischemia (Me-Is) after cardiac surgery is underreported in present literature but has still earned the bad reputation of a dismal prognosis. This study adds clinical outcomes in a large patient cohort. Between 2009 and 2019 of the 22,590 patients undergoing cardiac surgery at our facility 106 (0.47%) developed Me-Is postoperatively. Retrospective patient data was analyzed. Additionally, patients were stratified by outcome-survivors and nonsurvivors. Patients were predominantly male (n = 68, 64.2%), mean age was 71.2 ± 9.3 years. Most procedures were elective (n = 85, 80.2%) and comprised of more complex combined procedures (50.9%) and redos (17.9%). Mean EuroSCORE II averaged 10.9 ± 12.2%. Survival at 30 days was 49.1% (n = 52). Clinical baseline and procedural characteristics did not differ significantly between survivors and nonsurvivors. The median postoperative interval until symptom onset was 5 days in both groups. Survivors were more frequently diagnosed by computed tomography and nonsurvivors based on clinical symptoms. Me-Is was predominantly nonocclusive (n = 84, 79.2%). Laparotomy was the main treatment in both groups (n = 45, 78.8% vs. n = 48, 88.9%, p = 0.94). Predictors of mortality were maximum norepinephrine doses (hazard ratio [HR] 8.29, confidence interval [CI] 3.39-20.26, p < 0.0001), lactate levels (HR 1.06, CI 1.03-1.09), and usage of inotropes (HR 2.46, CI 1.41-4.30). The prognosis of Me-Is following cardiac surgery is poor-independently from diagnostic or treatment patterns. There exists a significant asymptomatic time period postoperatively, in which pathophysiologic processes seem to cross the Rubicon. After clinical demarcation, the further course can almost no longer be influenced.

Treatment, healthcare utilization and outcomes in patients with glioblastoma in Ontario: a 10-year cohort study.

Glioblastoma (GBM) is the most common malignant primary brain tumour in adults. Receipt of adjuvant therapies has been shown to exert a significant positive effect on patient survival. Little is known however about how changes in standards of care and healthcare system factors, such as access, affect real-world outcomes. In this study, we provide an overview of GBM in Ontario and examine elements of care, including treatment patterns, healthcare utilization, and overall survival, from 2010 to 2019, to interpret the impact of the changes in practice standards and expansion of the care network within this period. Using linked health-administrative databases from Ontario, Canada, we conducted a population-based cohort study to examine the clinical and biological characteristics, treatment, and healthcare utilization patterns of adult GBM patients diagnosed between 2010 and 2019. The primary outcomes were enrollment in adjuvant chemoradiation treatment and 1-, 2-, and 5-year survival. All analyses were performed using the Statistical Analysis Software (SAS). 5392 patients were diagnosed with GBM in Ontario from 2010 to 2019 (58% male, 42% female). The median age at diagnosis was 64. Receipt of adjuvant chemoradiation within one year of diagnosis increased from 51% in 2010 to 63% in 2019. 1-year, 2-year, and 5-year overall survival for all patients remained stable, ranging between 40 and 43%, 15-19%, and 5-7%, respectively. For patients above the age of 65, however, 1-year survival increased from 19% in 2010 to 26% in 2019. Regionalization enabled access to treatment closer to home for many patients. Over the last decade, receipt of adjuvant chemoradiation increased among elderly patients, but the improvement in 1-year overall survival over time was accounted for by sociodemographic and clinical covariates. Our findings support the efforts for regionalization of services to improve accessibility. This Ontario-based study provides insight into the effect of practice evolution and healthcare utilization on the overall survival of patients with GBM. Overall survival for most patients with glioblastoma has remained stagnant over the past decade. Changes in treatment standards and expansion of access to treating centres have been associated with prolonged survival in elderly glioblastoma patients.

Sociodemographic, clinical characteristics, and treatment patterns of endometrial cancer cases in Puerto Rico during the period 2009 to 2015: A retrospective study.

Over the past decades, the rising incidence rates of endometrial cancer have made it a significant public health concern for women worldwide. Treatment strategies for endometrial cancer vary based on several factors such as stage, histology, the patient's overall health, and preferences. However, limited amount of research on treatment patterns and potential correlations with sociodemographic characteristics among Hispanics is available. This study analyzes the treatment patterns for patients diagnosed with endometrial cancer in Puerto Rico. A secondary database analysis was performed on endometrial cancer cases reported to the Puerto Rico Central Cancer Registry-Health Insurance Linkage Database from 2009 to 2015 (n = 2,488). The study population's sociodemographic and clinical characteristics were described, along with an overview of the therapy options provided to patients receiving care on the island. Logistic regression models were used to evaluate the association of sociodemographic/clinical characteristics with treatment patterns stratified by risk of recurrence. In our cohort, most patients were insured through Medicaid and had a median age of 60 years. Almost 90% of patients received surgery as the first course of treatment. Surgery alone was the most common treatment for low-risk patients (80.2%). High-risk patients were more likely to receive surgery with radiotherapy and chemotherapy (24.4%). Patients with Medicare insurance were five times (HR: 4.84; 95% CI: 2.45-9.58; p < 0.001) more likely to receive surgery when compared with patients insured with Medicaid. In contrast, those with private insurance were twice as likely to receive surgery (HR: 2.38; 95% CI: 1.40-4.04; p = 0.001) when compared to those with Medicaid. These findings provide insight into the treatment patterns for endometrial cancer in Puerto Rico and highlight the importance of considering factors such as disease risk when making treatment decisions. Addressing these gaps in treatment patterns can contribute to effective management of endometrial cancer.

Abstract PO1-17-08: Post-approval treatment patterns and tolerability of neratinib in HER2+ early-stage breast cancer

Abstract Background: While the approval status for neratinib in HER2+ early-stage breast cancer (EBC) allows its use following any trastuzumab-based therapy, the phase 3 ExteNET trial (NCT00878709), which yielded an improvement in disease-free survival, was conducted when single-agent adjuvant trastuzumab was standard of care (SOC) and before approvals of adjuvant pertuzumab + trastuzumab (FDA-approved 2017) or trastuzumab emtansine (T-DM1; FDA-approved 2019). Given recent changes in SOC for HER2+ EBC, health care professionals may seek contemporary and real-world information regarding treatment patterns and tolerability of neratinib. Methods: A literature review was performed to identify studies that characterized trends in use of extended adjuvant neratinib in HER2+ EBC. Due to differences in study design (interventional, observational, claims data) and populations studied, a descriptive summary of data is presented in lieu of statistical cross-study comparisons. Results: Following FDA approval of neratinib in HER2+ EBC in 2017, five studies have reported treatment patterns of extended adjuvant neratinib in a clinical trial or real-world setting; three studies included safety data (Table 1). In the phase 2 CONTROL trial (NCT02400476; N=563; 2015–2021), approx. 82%, 17%, and 1% of neratinib-treated pts received prior adjuvant trastuzumab, pertuzumab, or T-DM1, respectively, and prior neoadjuvant/adjuvant pertuzumab did not affect rates of grade ≥3 diarrhea, diarrhea-related discontinuations, or treatment duration.1 In an interim analysis of the observational ELEANOR study (NCT04388384; N=187; 2020–ongoing), approx. 41%, 33%, and 19% of neratinib-treated pts received prior adjuvant trastuzumab (as their only anti-HER2 treatment), pertuzumab + trastuzumab, or T-DM1, respectively; corresponding rates of grade ≥3 diarrhea were 19%, 25%, and 14%, respectively, with no new safety signals reported.2 In a chart review from the US Oncology Network (N=166; 2017–2020), approx. 99%, 43%, and 2% of neratinib-treated pts received prior adjuvant trastuzumab (56% as their sole anti-HER2 treatment), pertuzumab, or T-DM1, respectively.3 Diarrhea was mainly moderate (29%; n=43/150) or mild (22%; n=33/150), with few severe cases (1%; n=2/150).3 In a retrospective analysis employing the IQVIA claims database (N=385; 2017–2021), prior use of recently approved adjuvant agents increased over time, with rates of prior pertuzumab + trastuzumab or prior T-DM1 as high as 52% and 14%, respectively, in 2020.4 In the Neat-HER virtual registry (N=46; 2018–2021), approx. 41% and 11% of neratinib-treated pts received prior adjuvant pertuzumab or T-DM1, respectively.5 Conclusions: Recent studies have observed neratinib use in clinical practice following adjuvant trastuzumab-based therapy including pertuzumab + trastuzumab or T-DM1. Preliminary data suggest a similar safety profile for pts with/without prior pertuzumab. These datasets are limited by the fact that: (1) some pts were enrolled in the CONTROL trial prior to launch of adjuvant T-DM1 and pertuzumab; (2) the interval between T-DM1 launch in Europe and start of the ELEANOR study was relatively short; and (3) not all toxicity measures were formally graded. A summary of available safety and effectiveness results is forthcoming. Additional interventional and non-interventional studies will continue to evaluate the safety and effectiveness of neratinib following current SOC adjuvant therapy in HER2+ EBC. Table 1. Treatment patterns of HER2-targeted adjuvant agents preceding neratinib use in HER2+ EBC ITT, intent-to-treat; T-DM1, ado-trastuzumab emtansine. aTherapies were recorded as used for adjuvant therapy in CONTROL, ELEANOR, US Oncology, and Neat-HER. CONTROL includes unpublished data. In the IQVIA claims analysis, HER2-targeted agent(s) used within 12 months prior to neratinib initiation were assumed to be adjuvant therapies. Pertuzumab use was generally taken in combination with trastuzumab as dual HER2 blockade and some pts received more than one anti-HER2 adjuvant treatment, for example T-DM1 in addition to pertuzumab plus trastuzumab. bAdjuvant trastuzumab monotherapy or in combination with chemotherapy unless noted otherwise. cThe proportion of patients who took at least one tablet of neratinib for ≥75% of the prescribed treatment days and did not take neratinib on days when neratinib was not prescribed. dData forthcoming. eIncludes prior trastuzumab monotherapy and trastuzumab used in combination with pertuzumab; 93/166 pts (56%) received trastuzumab as their only anti-HER2 agent (monotherapy or in combination with chemotherapy; unpublished data). fIncludes prior trastuzumab monotherapy as well as trastuzumab used in combination with pertuzumab. References Citation Format: Kelly McCann, Nadia Harbeck, Debu Tripathy, Arlene Chan, Jay Andersen, Joyce O'Shaughnessy, Gregory Vidal. Post-approval treatment patterns and tolerability of neratinib in HER2+ early-stage breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-17-08.

Abstract PO2-11-02: Incidence, treatment patterns and outcomes of breast cancer during the first year of the COVID pandemic: A population-based study

Abstract Background: The COVID pandemic created significant challenges in breast cancer (BC) care which were most pronounced during 2020 when screening and treatment access were reduced. The aims of this study were to evaluate and compare the incidence of BC, treatment patterns, and outcomes during the year 2020 versus the immediate pre-pandemic (2018 and 2019) period. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) program, we calculated age-adjusted incidence rates of ductal carcinoma in situ (DCIS) and invasive BC during 2018, 2019 and 2020, with a 95% confidence interval (CI) for each. In the invasive BC cohort, we compared chemotherapy and radiation utilization by year. To account for potential misclassification of cause of death (COD) during the pandemic, we evaluated outcomes by overall survival (OS) in the invasive cohort, defined as time from BC diagnosis until death from any cause. To assess the impact of COVID, OS was truncated at 12 months from diagnosis for each year and we compared OS at 12 months for patients (pts) diagnosed with invasive BC in 2020 versus 2018 and 2019. OS was compared in a multivariable Cox model with diagnosis year 2020 as the reference. The Cox model was adjusted for age at diagnosis, race and ethnicity, sex, tumor grade, histology, stage, tumor subtype, surgery, radiation, chemotherapy, marital status, median household income, and rurality. Results: There were 37,834 DCIS diagnoses, and 199,594 invasive BC diagnoses between 2018-2020, with the distribution by year shown in the table. In 2020, the age-adjusted incidence of female DCIS decreased to 31.0 cases per 100,000, and the age-adjusted incidence of female invasive BC decreased to 166.6 cases per 100,000. As shown in the table, the incidence of male BC did not change. Among females, the relative reductions in incidence from 2019 to 2020 were: 15% for DCIS, 12% for stage I, 6% for stage II, 3% for stage III, and 2% for stage IV. Comparing 2020 to 2018-2019, we observed small absolute decreases in the proportions of pts who had surgery (2%) or radiation therapy (2.8%), and a small absolute increase in chemotherapy (1.4%) (p&amp;lt; 0.001 for each). These treatment changes were present across each individual stage. The table shows the 12-month OS rates for each year of diagnosis. COVID was the COD for 77 pts in 2020, 43 pts in 2019 and 0 pts in 2018. In the Cox model, there were no significant differences in the risk of death between pts diagnosed 2018 and 2020 (adjusted Hazard Ratio: 0.95; 95% CI, 0.90 – 1.01; p=0.13) or between pts diagnosed 2019 and 2020 (adjusted Hazard Ratio: 0.95; 95% CI, 0.89 – 1.01; p=0.08). Conclusions: During the first year of the pandemic, the incidence of BC decreased significantly, largely driven by a decrease in DCIS and early-stage diagnoses. Of interest, there was no stage shift observed with respect to the incidence of stage III or de novo stage IV disease, and no change in male BC incidence. We hypothesize that the observed trends are due to a reduction in screening, but this needs further study. It will be critical to evaluate future trends in cancer incidence beyond 2020, as it is possible that the reduction in early-stage diagnoses represent missed diagnoses that will be identified at a later stage in subsequent years. Finally, while there was no difference in 12-month OS by year of diagnosis, the true impact of the COVID pandemic on BC-specific outcomes will require further follow-up. Citation Format: Jose Leone, Julieta Leone, Michael Hassett, Rachel Freedman, Jorge Avila, Carlos Vallejo, Nabihah Tayob, Sara Tolaney, Nancy Lin. Incidence, treatment patterns and outcomes of breast cancer during the first year of the COVID pandemic: A population-based study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-11-02.

Abstract PO3-05-03: Real-World Data on First-line Treatment of Hormone Receptor-positive, HER2-negative, Metastatic Breast Cancer in Brazil (BRAVE study - LACOG 0221)

Abstract Introduction: Endocrine therapy (ET) plus CDK 4/6 inhibitors is considered the standard of care as first-line therapy in hormone receptor positive (HR+)/HER2 negative (HER2-) metastatic breast cancer (mBC). Nonetheless, the use of chemotherapy (CT) is frequent in clinical practice, and access to CDK 4/6 inhibitors is limited in some countries. We used real-world data to describe treatment patterns, the impact of health insurance type, and outcomes among Brazilian patients with HR+/HER2- mBC treated in the first-line setting. Methods: In this observational retrospective study, female patients ≥ 18 years old diagnosed with de novo or recurrent HR+/HER2- mBC between January 2018 and December 2020 were included. Patients' data were extracted from medical charts or electronic health records (EHR). The primary endpoint was first-line treatment patterns in public and private health system cohorts. Key secondary endpoints were progression-free survival (PFS), defined as time from 1L treatment to progression or death, and overall survival (OS), defined as time from diagnosis of mBC until death or censoring. No formal statistical assumption was performed for sample size, the study recruited 2 cohorts of 150 patients from the public and 150 patients from the private health insurance system. Results: A total of 307 patients were included, 156 from public and 151 from private health insurance system, from 13 sites in Brazil. Median age was 56.8 (range 19.9-94.1), and 32.2% (N=99) had de novo MBC. Treatment patterns are described in Table 1. The most frequent treatment received in 1L was ET alone 42.4%, followed by CT (alone or CT followed by ET +- CDK4/6i) 31.6% and ET + CDK4/6i 25.1%. There was a significant difference between the 1L treatment with ET + CDK4/6i in the private and public systems, 48.3% vs 2.6%, p &amp;lt; .0001, respectively. The most frequently used CDK4/6i in 1L setting was Ribociclib (65.0%), followed by Palbociclib (36.9%) and Abemaciclib (7.1%). There was an increase in the use of CDK4/6i over time, 17% in 2018, 30.0% in 2019, and 27.9% in 2020. With a median follow-up of 32.2 months (95% CI: 29.4 - 34.4), the median 1L PFS was 22.9 months (95% CI: 16.9 - 25.2) in the public and 21.8 months (95% CI: 17.7 - 31.1) in the private health system, p=0.92. Median 1L PFS by treatment received was 13.6 months (95% CI: 6.1-39.0) with CT, 18.4 months (95% CI: 12.1-22.1) with CT followed by ET +-CDK4/6i, 21.9 months (95% CI: 17.3-25.5) with ET and 31.1 months with ET plus CDK 4/6i (95% CI: 15.8-42.8). Overall, median OS was 52.8 months (95%CI 49.4-NR). The 4-year OS rate per 1L treatment received were 50.3% (95% CI: 28.7-68.5) with CT, 39.0% (95% CI: 13.9-63.8) CT followed by ET +- CDK4/6i, 74.4% (95% CI: 58.0-85.1) with ET alone, 71.3% (95% CI: 49.6-85.0) ET + CDK4/6i, 50.3% (95% CI: 28.7-68.5) with CT and 39.0% (95% CI: 13.9-63.8) CT followed by ET +- CDK4/6i. Conclusion: ET is the most commonly used 1L treatment in clinical practice in Brazil, followed by ET + CDK4/6i and CT. A large difference in CDK4/6i use was observed between private and public health systems, reflecting the current limited access to CDK4/6i in Brazil. This study highlights treatment disparities within a nation with a fragmented health insurance system. Table 1. Treatment Patterns in Public and Private Healthcare Systems Citation Format: Gustavo Werutsky, Daniela Rosa, Tomás Reinert, Romualdo Barroso-Sousa, Heloísa Resende, Poliana Signorini, Eduardo Cronenberger, Juliana Góes Martins Fagundes, Jorge Henrique Santos Leal, Marina Dutra Giffoni, Aline Vieira, Luiza Nardin Weis, Jose Marcio Figueiredo, Tatiana Correa, Fernando Castilho Venero, Luisa Mostardeiro Tabajara Franche, Marina Musse Bernardes, Rafaela Jesus, Gustavo Gössling, José Bines. Real-World Data on First-line Treatment of Hormone Receptor-positive, HER2-negative, Metastatic Breast Cancer in Brazil (BRAVE study - LACOG 0221) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-05-03.

Abstract PO1-16-07: Patient Characteristics and Treatment Sequencing Among HER2-low Metastatic Breast Cancer Patients with Rapid vs. Delayed Progression on First-line Endocrine Therapy

Abstract Background Patients with HER2-low (IHC 1+ or 2+ and negative ISH) and hormone-receptor positive (HR+) metastatic breast cancer (mBC) who rapidly progress on first-line (1L) endocrine therapy may experience different treatment pathways than those with delayed progression. The goal of this multisite study is to describe the characteristics, treatment patterns and outcomes of these patients with rapid vs. delayed progression. Methods This was a retrospective cohort study of HER2-low, HR+, mBC patients who received 1L endocrine-based treatment regimen at the Huntsman Cancer Institute, Moffitt Cancer Center, and the Winthrop P. Rockefeller Cancer Institute between 2017 and 2021. With no conventional definition, our study defined rapid progression as disease progression within 12 months of 1L treatment initiation vs &amp;gt;12 months/no progression during study follow-up as delayed progression. Demographic and clinical characteristics, and 1L and second-line (2L) treatment patterns were assessed using descriptive statistics. Using Kaplan-Meier analysis, overall survival (OS) was estimated from treatment initiation to death while progression-free survival (PFS) was estimated from treatment initiation to death or disease progression according to physician notes in patients’ charts. Censoring was performed at the date of last follow-up or 31 Dec 2021, whichever occurred earlier. Results The study included 118 patients who received 1L endocrine therapy (see table), mostly in combination with a CDK4/6 inhibitor (n = 87, 73.7%). Rapid progression was observed for 25 (21.2%) patients with a median 1L PFS and OS of 6.4 months (95% CI: 5.4-8.2) and 20.5 months (95% CI: 14.4-30.5), respectively, compared to delayed progressors (median 1L PFS = 30.5 months, 95% CI: 21.5-54.2 and median OS = 62.1 months, 95% CI: 46.4 -upper bound not reached). Rapid progressors were more likely than delayed progressors to be current smokers (n = 6, 24.0% vs n = 7, 7.5%, p = 0.015) or had liver metastasis at diagnosis of advanced disease (n = 11, 44.4% vs n = 17, 18.3%, p = 0.007) but less likely to have bone as the only metastasis site (n = 6, 24.0% vs n = 46, 49.5%, p = 0.023). A smaller proportion of rapid progressors were on CDK4/6 inhibitors in 1L (n = 17, 68.0%) compared to delayed progressors (n = 70, 75.3%) but the difference was not statistically significant. A substantial proportion of rapid progressors (68%, n = 17) continued to receive endocrine therapy in 2L, including endocrine therapy alone (n = 6, 24.0%), endocrine therapy with targeted therapy (n = 6, 24.0%) and endocrine therapy with CDK4/6 inhibitors (n = 5, 20.0%). Among patients on 1L endocrine therapy who continued to a 2L treatment, 2L PFS and OS of rapid progressors (n = 24) were 5.7 months (95% CI: 3.2-10.6) and 14.1 months (95% CI: 6.8-24.2), respectively, compared to 9.2 months (95% CI: 3.1-13.7) and 29.2 months (95% CI:14.4- upper bound not reached) among delayed progressors (n = 39). Conclusion In this study of patients with HER2-low and HR+ mBC, many patients with rapid disease progression on 1L endocrine-based regimens continued to receive endocrine therapy in their next line of therapy and experienced poor clinical outcomes. This preliminary chart review study highlights the unmet need for more effective treatments for patients with rapid progression on 1L endocrine-based regimens. Further research with a larger sample size is warranted to confirm these findings. Patient characteristics and treatment patterns Demographic characteristics and treatment patterns of stage IV breast cancer patients with HER2-low disease and received 1L endocrine therapy Citation Format: Chia Jie Tan, Connor Willis, Trang Au, Matthew Schabath, Chenghui Li, Kristen Kelley, Xiaoqing Xu, Leah Park, Clara Lam, Sandhya Mehta, Jackie Kwong, Diana Brixner, David Stenehjem. Patient Characteristics and Treatment Sequencing Among HER2-low Metastatic Breast Cancer Patients with Rapid vs. Delayed Progression on First-line Endocrine Therapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-16-07.

Abstract PO5-19-04: EVOLVE: An Ambispective, Patient-Centered, Real-World Early-Stage Breast Cancer Study in the United States

Abstract Background: While survival for patients with early breast cancer (eBC) has greatly improved with earlier detection and modern treatments, the risk of recurrence and long-term/late treatment-related adverse events (AEs) remain concerns for many patients. Contemporary real-world data are needed to understand current diagnostic pathways, treatment patterns and toxicities, quality of life, and patient experience to better characterize eBC care and knowledge gaps and establish important hypotheses to test in prospective trials, with the ultimate goal to improve both treatment and outcomes for patients with eBC. Study design: PicnicHealth and AstraZeneca are collaborating to build a real-world observational eBC cohort composed of de-identified medical records data supplemented with patient-reported outcomes (PROs), including patient-reported social determinants of health (SDoH). Patients recruited from multiple channels, such as digital marketing and community partnerships, will consent to participate and sign HIPAA authorization for PicnicHealth to collect their medical records from all providers and sites of care in the United States. All available retrospective medical records in any format will be retrieved, and records will continue to be collected for patients prospectively following enrollment. Disease-specific information will be abstracted using PicnicHealth’s human-in-the-loop machine learning abstraction platform. Patients will have access to their records in the form of a searchable and shareable digital timeline. Additional data, including but not limited to symptoms, quality of life and treatment experience will be collected through surveys. The first patient was enrolled in May 2023. Patients will be followed for ≥8 years or until withdrawal or death, whichever occurs first. Eligibility criteria: Patients with stage I-III breast cancer diagnosed ≤3 years before enrollment, who onboard to the PicnicHealth platform, consent to participate, sign HIPAA authorization for medical record collection, and provide ≥1 provider/care site for record retrieval will be included in the cohort. Specific aims: The cohort aims to generate contemporary real-world data relevant to understanding demographic and clinical characteristics, SDoH, diagnostic/testing pathways, treatment patterns, and clinical outcomes, including AEs and AE management. Specifically, demographic and SDoH differences in management, outcomes, and the patient experience during and following eBC diagnosis and treatment will be evaluated. The cohort design and the data collected will evolve as the eBC landscape evolves to continuously address new research questions around diagnosis, management, outcomes, and patient experience. Statistical methods: The demographics, SDoH, clinical characteristics, treatments, healthcare resource utilization, eBC outcomes, such as recurrence and progression, and patient experience will be summarized for the cohort overall and by pre-determined subgroups using descriptive statistics. Additional analyses include, but are not limited to, evaluating the impact of key exposures, such as SDoH, on treatment and diagnostic pathways, treatment compliance, clinical outcomes, and PROs. All analyses will be prespecified in study-specific statistical analysis plans. Present accrual and target accrual: At least 3,000 patients will be enrolled in the PicnicHealth eBC Cohort. As of July 2023, 843 patients have onboarded to the PicnicHealth platform and will be screened for eligibility into the eBC registry cohort. Contact information for people with a specific interest in the study: For additional information, please contact breastcancer@picnichealth.com. Citation Format: Haley Friedler, Meghan Tierney, Melinda Baker, Gillian Hanson, Josefa Briceno, Karen Smith, Michele Baber, Kara Glover, Xiaoqing Xu, Kellie Ryan, Zulikhat Segunmaru, Clara Lam, Maryam Lustberg, N. Lynn Henry, Rachel Greenup, Marianna Chavez, Joseph Unger, Alice Ho, Deborah Collyar. EVOLVE: An Ambispective, Patient-Centered, Real-World Early-Stage Breast Cancer Study in the United States [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-19-04.

Abstract PO3-16-08: Real-World Treatment Patterns in Elderly Patients with HER2-Negative Early Breast Cancer

Abstract Background: As the treatment landscape of human epidermal growth factor receptor 2-negative (HER2–) early breast cancer (BC) evolves, an understanding of treatments given in real-world settings to elderly patients with HER2– early BC is needed to gain insight into the potential unmet needs of this population for whom clinical data are limited. This study described demographics, clinical characteristics, and neoadjuvant and adjuvant treatment patterns in elderly patients with HER2– early BC in the United States. Methods: This retrospective study used SEER-Medicare data (2010–2019) to identify patients aged ≥66 years with HER2– early (Stage I–III) BC receiving primary surgery. Patient characteristics were evaluated at primary surgery or at BC diagnosis. Neoadjuvant and adjuvant therapies were defined as any National Comprehensive Cancer Network-recommended regimens received between BC diagnosis and primary surgery, and during the 180-day period following primary surgery, respectively. Patient characteristics were described using means and standard deviations (SDs) for continuous characteristics, and frequencies and proportions for categorical characteristics. Neoadjuvant and adjuvant therapies were summarized using frequencies and proportions. All analyses were conducted for the overall population and stratified by breast cancer subtype (hormone receptor-positive [HR+]/HER2– vs. triple negative BC [TNBC]) and stage at diagnosis (Stage I vs. Stage II/III). Results: Of 28,655 eligible patients, 25,899 (90.4%) had HR+/HER2– BC and 2,756 (9.6%) had TNBC; 17,961 (62.7%) had Stage I BC and 10,694 (37.3%) had Stage II/III BC. Mean (SD) age at diagnosis was 75.8 (6.4) years, mean (SD) National Cancer Institute comorbidity index was 1.9 (2.1), and 23.7% received single or multi-gene testing for a breast cancer gene 1 and/or 2 (BRCA1/2) mutation (HR+/HER2– BC: 24.6%; TNBC: 15.5%), with most (86.3%) testing occurring after primary surgery. Relative to HR+/HER2– BC patients, TNBC patients were less likely to present with Stage I disease (46.7% vs. 64.4%), had a larger mean tumor size at diagnosis (2.6 cm vs. 1.9 cm), and higher-grade tumors (Grade III or IV: 70.6% vs. 14.6%). TNBC patients were also more likely to receive neoadjuvant chemotherapy (90.9% vs. 35.3%) and adjuvant radiation therapy (81.2% vs. 66.4%) than HR+/HER2– BC patients (Table 1). By BC stage, neoadjuvant therapy was more common among Stage II/III patients relative to Stage I patients (12.3% vs. 2.7%), with most (90.4%) neoadjuvant chemotherapy use observed among Stage II/III patients. Adjuvant therapy use was similar between Stage I and Stage II/III patients (87.4% vs. 88.1%) and the most common adjuvant therapies across both subgroups were endocrine therapy (85.2% vs. 82.2%) and radiation therapy (68.5% vs. 66.1%). Conclusion: In elderly patients with HER2– early BC, treatment with adjuvant therapy was common, while neoadjuvant therapy was limited. Moreover, one in four HER2– early BC patients were tested for a BRCA1/2 mutation in real-world clinical practice. Our findings highlight the need for a better understanding of the role of increased and timely BRCA1/2 testing to inform optimal treatment strategies across neoadjuvant and adjuvant settings in this population. Table 1. Treatment Patterns Among Patients with TNBC and HR+/HER2– Early Breast Cancer Citation Format: Jagadeswara Earla, Allison Kurian, Kalé Kponee-Shovein, Ambika Satija, Yan Song, Nathaniel Downes, Malena Mahendran, Qi Hua, Arun Kumar, Jaime Mejia. Real-World Treatment Patterns in Elderly Patients with HER2-Negative Early Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-16-08.

Abstract PO2-10-07: Patterns of presentation, treatment and survival for older patients with metastatic breast cancer (MBC): results from a large prospective registry

Abstract Background: The median age of breast cancer diagnosis in the U.S. is 62 years; however, older pts with breast cancer are consistently underrepresented in clinical research. In population-based studies, older pts, particularly those aged 70+, do worse than their younger counterparts at every stage of disease, including stage IV. However, our understanding of patterns of recurrence, treatment patterns, and outcomes for older pts with MBC is limited by a lack of available data. Methods: We identified pts age &amp;gt;60 years seen at least once at a single, NCI-designated cancer center for a diagnosis of MBC between 1999-2022 with 1+ years of follow-up from the time of their metastatic diagnosis. We categorized pts into 5-year age groups (60-65; 66-70; 71-75; 76-80; &amp;gt;80) and two groups of 60-70 and &amp;gt;70. Clinicopathologic characteristics, treatment patterns, reason for treatment discontinuation, and the proportion enrolling on clinical trials were compared by tumor subtype and age group using Chi-Square testing. Median overall survival using Kaplan-Meier method was calculated from the date of initial MBC diagnosis to date of death or last follow-up, examined by tumor subtype and age. Results: The final analytic cohort included 1,115 patients diagnosed with MBC with median follow-up of 2.9 years (1.0-18.5). Median age at MBC diagnosis was 66.3 years (60.0-95.4) and 10% were non-White; disease subtype distribution was the following: 70.7% HR+HER2-, 11.9% HER2+, 17.4% TN. Overall, 22.2 presented with de novo MBC. Presentation of MBC did not vary by ages 60-70 vs. 70+, with no differences in disease characteristics such as grade and disease sites at MBC diagnosis (except for bone). However, the proportion of pts with HR+HER2- disease increased with age, from 69% of MBC in ages 60-70 and 76% in ages &amp;gt;70 (p=.02). In pts with this subtype receiving first-line (1L) therapy (n=783), use of endocrine therapy as 1L (with or without a CDK4/6 inhibitor) increased by age (77.8% in ages 60-65 v. 94.7% in ages &amp;gt;80); use of 1L chemotherapy also varied by age (22.2% in ages 60-65 v. 5.3% in &amp;gt;80). Among pts with HER2+ BC, 89% received a trastuzumab-containing regimen in the 1L setting; in pts with TN MBC, 94% received at least 1L line of chemotherapy. Overall, most pts discontinued 1L therapy for progression, not toxicity, and there was no variation in rates of discontinuation due to toxicity by age with 10.4% noted in both age groups, 60-70 and &amp;gt;70. The proportion of patients receiving 3+ lines of chemotherapy across disease subtype decreased with increasing age (e.g., 54% in ages 60-65 v. 25% in ages &amp;gt;80 among HR+HER2-; 69% in ages 60-65 and 33% in ages &amp;gt;80 among TN MBC). Overall, enrollment on a clinical trial in the MBC setting steadily decreased with older age from 40% in ages 60-65 to 13% in ages &amp;gt;80 (p=.0004). Overall median overall survival differed with increasing age from 4.4 yrs in ages 60-65 to 2.7 yrs in ages &amp;gt;80 (p&amp;lt; 0.005). In descriptive analyses, the proportion of pts alive at 2 yrs was variable. For those ages 60-65, 37.8%, 17.1%, and 42.9% of pts with HR+HER2, TN, and HR-HER2+, respectively were alive at 2 yrs. For those ages &amp;gt;80, 23.7%, 0%, and 0% of pts with HR+HER2-, TN, and, HR-HER2+ disease were alive at 2 yrs. Median survival times were &amp;lt; 2 years for pts with TN regardless of age. Conclusions. In a unique, large prospective cohort of older pts with MBC, we examined detailed information on disease presentation, treatments, and outcomes, lending new information on patterns of care and experiences for older pts with MBC in a modern real-world experience. Limitations include a single center experience and small numbers of older pts with HER2+ and TN disease. Although the oldest pts with MBC had similar disease characteristics as younger pts in our dataset, survival outcomes were poor, particularly for those ages 80+. Therapeutic approaches, likely including improved supportive care, are urgently needed to optimize outcomes in the oldest pts with MBC. Table 1. Outcomes for older pts with MBC Citation Format: Melissa Hughes, Alyssa Patterson, Alexandra Newman, Amanda Higgins, Gregory Kirkner, Janet Files, Molly Skeffington, McKenna Moore, Sarah Strauss, Nicole Kuhnly, Lindsey Crowley, Sara Tolaney, Nancy Lin, Rachel Freedman. Patterns of presentation, treatment and survival for older patients with metastatic breast cancer (MBC): results from a large prospective registry [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-10-07.

Abstract PO1-06-08: Treatment utilization by race and insurance type among triple negative breast cancer patients

Abstract Introduction Triple negative breast cancer (TNBC) is associated with poorer prognosis and its lower long-term survival rates disproportionately affect people of racial and ethnic minority groups. Ensuring timely and effective treatment for all patients regardless of race or insurance status is critical. The objective of this study is to describe treatment patterns by line of therapy, race, and insurance type to identify barriers to accessing healthcare using a physician survey and patient-chart review. Methods This study employed a 60-minute physician survey and linked retrospective chart review of patients’ charts conducted June-July 2022. Participating oncologists across the US (34% Central; 19% Southeast; 18% Northeast; 21% West; 9% East Coast) were required to be board-certified, in practice 3 to 30 years post-residency, and managing at least 7 patients with TNBC in the past 3 years. Oncologists extracted patient-level data from 2-4 patient records for the chart review. A convenience sample of charts oversampled patients on Medicaid, Black and Latina patients, and patients with later stage TNBC to allow for robust disparities analysis. Data collection included provider characteristics, treatment by line of therapy (LOT), rationale for treatment decisions, barriers experienced in accessing care, and support services used. Results Participating oncologists (n=101, 73% male; 62% community vs 39% academic setting) provided data on 283 patients with TNBC [99% female; median age = 46.0 years; race = Black (42%), Latina (31%), White (25%) or Other (2%); geographic location = Urban (53%), Suburban (39%), Rural (8%)]. White patients were more likely to be covered by private insurance (73%) compared to Black (25%) and Latina patients (32%). Black and Latina patients were more likely to be covered by Medicaid (White, 16%; Black, 71%; Latina, 52%). Over half of patients needed prior authorization for first-line (1L) treatment; mean wait time for prior authorization was 1.5 weeks. Black patients (58%) were more likely to require prior authorization in 1L as compared to White patients (49%); There were no significant differences in prior authorization requirements based on type of insurance (Medicaid, Medicare, Private/Commercial Insurance). Of the 283 patients treated with 1L therapy, 111 patients received second-line (2L) treatment [Black (n=52, 44%), Latina (n=29, 32%), White (n=26, 37%), Other (n=4, 71%)], and 45 patients received third-line (3L) treatment [Black (n=25, 21%), Latina (n=9, 10%), White (n=9, 13%), Other (n=2, 33%)]. Chemotherapy was the most common 1L (75%) and 2L (51%) treatment. Targeted therapy (TT), defined as immunotherapy, hormone therapy or antibody–drug conjugates, was most common in 3L (64%). A smaller proportion of Black patients who progressed to 3L received TT (n=13, 52%) compared to White (n=8, 89%) and Latina (n=7, 78%) patients. A larger proportion of patients with private/commercial insurance (n=18, 95%) received TT in 3L as compared to patients with Medicaid (n=10, 42%) or Medicare (0%). Conclusions Findings indicated disparities both in pre-treatment barriers (specifically prior authorization) and the utilization of targeted therapy in later lines of therapy among Black patients. Although treatment patterns did not seem to differ by race in early lines of therapy, numerical differences in treatment patterns by race and insurance type emerged in later lines of therapy. Given the poor prognosis for patients diagnosed with TNBC and its disproportionate impact on communities of color, future policy efforts should be focused on achieving equity in treatment initiation and use of TT in TNBC patients. Citation Format: Natalia Sadetsky, Langa Bakhuluma-Ncube, Emily Fox, Laura Okpala, Matt O'Hara, Jennifer Parr. Treatment utilization by race and insurance type among triple negative breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-06-08.

Abstract PO1-09-12: Cancer health disparities among patients with early-stage estrogen receptor-positive (ER+) breast cancer treated in public or private practices in Brazil

Abstract Background Cancer registries in Brazil are deficient and data about patients’ profiles and cancer treatment patterns are scarce in the country. Moreover, while 30% of population has access to private insurance, almost 70% of population uses publicly health services. The objective of this work was to describe the sociodemographic and clinicopathological characteristics of women with early-stage ER+ breast cancer on adjuvant ET in different regions of Brazil, and to describe treatment patterns for this disease according public and private institutions. Methodology: We performed a real-world data analysis in different institution regions of Brazil. Women with a history of early-stage ER+ invasive carcinoma of the breast on adjuvant endocrine therapy for at least 6 months were invited to participate of this study in 12 centers in four different regions in Brazil. Demographic and clinicopathologic information was retrieved from medical records. In order to compare healthcare insurance type, we considered patients who were treated under the Brazilian public health system as publicly insured, and women who had private insurance or paid for their treatment as privately insured. High education level was defined by completed high school. Data collection was done with RedCap software. Qualitative variables were compared between groups using the Chi-square or exact Chi-square test and for quantitative variables the non-parametric Mann-Whitney test was used. P &amp;lt; 0.05 was considered significant. Analyzes were performed in SAS 9.4; Results: From June 2021 to May 2023, a total of 461 women with ER+, early BC, were included in this analysis. A total of 233 (50.6%) came from private institutions, the mean age was 56.02 years (range 22-93), 47.69% were non-white, 61.3% were post-menopause, 61.7% lived with a partner, and 76.2% were highly educated and 66.81% had comorbidities. Tumor staging at diagnosis was classified as III, II and I respectively in 21.26%, 43.17% and 35.57% of all cases. Regarding treatment received, 62.4% of patients underwent lumpectomy, 32.2% had axillary dissection, 67.6% received (neo)adjuvant chemotherapy, 45.2% were on aromatase inhibitors and 14.19% were on ovarian function suppression plus ET . Median duration of ET use was 2.78 years (range 6 months- 9.61 years). Publicly health insurance was associated significantly associated with younger age at diagnosis (&amp;lt; 60 yo), premenopausal status, to live alone, lower educational level, more advanced tumors, prior mastectomy, prior axillary dissection, prior neo-adjuvant chemotherapy, prior radiotherapy, lower use of aromatase inhibitors, ovarian function suppression plus ET, and CDK4/6 inhibitors, while higher use of concomitant medications. Conclusion: The study shows significant health disparities among women with early-stage ER+ breast cancer treated in private versus public institutions in Brazil. Importantly, despite having more advanced tumors, women in public institution had less access to ovarian suppression, CDK4/6 inhibitors and were treated with more aggressive surgical procedures. A deep discussion involving government, lawmakers, health care providers and patients should be conducted to try to decrease the described disparities. Patient’s characteristic and patterns of treatment among patients with estrogen receptor-positive breast cancer on adjuvant therapy according to health insurance in Brazil ALND: axillary lymph node dissection; CDK4/6i: CDK4/6 inhibitors; ET: endocrine therapy; OS: ovary suppression. Citation Format: Romualdo Barroso-Sousa, Daniele Assad-Suzuki, Danielle Santos, Fernanda Moura, Sulene Oliveira, Anna Luiza Galvão, Bruno Souza, Amanda Castro, Monalisa Andrade, Andrea Shimada, Yuri Beckedorff, Maria Cristina Magalhães, Cristiano Souza, Carlos Paiva, Heloísa Resende, Daniela Pereira, Angelica Rodrigues, Daniela Rosa. Cancer health disparities among patients with early-stage estrogen receptor-positive (ER+) breast cancer treated in public or private practices in Brazil [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-09-12.

Treatment patterns in advanced/metastatic non-small-cell lung cancer in China: results from the CancerMPact® survey 2021.

Aim: To report the treatment patterns of advanced/metastatic non-small-cell lung cancer (NSCLC) in China from a physician survey (CancerMPact®). Materials & methods:A total of206 Chinese physicians from 27 cities in urban mainland China reported on their treatment of NSCLC in September 2021. Results: Platinum doublets received 70.5% utilization for squamous NSCLC with PD-L1 expression <1% in first-line, whereas nonsquamous NSCLC was treated with platinum doublets (35.2%) or bevacizumab with platinum doublets (35.3%). Checkpoint inhibitors were utilized in >50% of all PD-L1-positive NSCLC cases. Driver-mutated NSCLC was most frequently treated with targeted therapy or platinum-based combinations. Conclusion: NSCLC treatment in China varies by histology, PD-L1 statusand driver mutations, illustrating the complexity of decision-making for Chinese physicians as treatment markets expand.

Abstract PO2-17-01: Impact of the introduction of CDK4/6 inhibitors on treatment duration in patients with HR+, HER2– advanced breast cancer: Final analysis of TreatER+ight, a Canadian prospective, real-world, observational study

Abstract Background: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in combination with endocrine therapy (ET) are the established first-line targeted therapy (TT) for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2–) advanced breast cancer (ABC). TreatER+ight, the first prospective, real-world study evaluating the treatment patterns, safety and effectiveness of ET alone or ET + TT in Canadian patients with HR+, HER2– ABC (2016 to 2020) recorded ET as the standard of care (SOC) in the first interim analysis report. However, treatment with CDK4/6i combined with ET have rapidly evolved as the SOC in the metastatic setting. Methods: This prospective, multicenter, observational study (NCT02753686) enrolled patients with HR+, HER2‒ ABC with or without prior exposure to ET and up to one line of prior CT in the advanced setting. The patients were enrolled by the line of their therapy (first-line, second-line or third-line) and grouped into 2 cohorts (ET and ET + TT). Duration of therapy, and overall survival (OS) are estimated using Kaplan–Meier method. Here, we report the final outcome with CDK4/6i treatment evolution with sequencing strategy and duration in routine clinical practice. Results: At data cutoff (December 1, 2022), a total of 439 enrolled patients (ET, n=104; ET + TT, n=335) from 25 centers in Canada, constituted the full analysis set. The median age (range) was 71.5 (37.0–96.0) years in ET cohort and 65.0 (23.0-87.0) years in ET + TT cohort. About 84.6% and 66.4% were postmenopausal patients in the ET and ET + TT cohorts, respectively. Patients with ECOG PS scores 0 to 1 composed of 82.0% and 93.5% in the ET and ET + TT cohorts, respectively. In the overall population, ET alone and ET + CDK4/6i were the most common treatment received by patients in first-line (43.5% and 43.3%) and second-line (36.3% and 24.6%) treatment settings. In third-line treatment setting, CT was the most common treatment received by patients (38.4%). Conclusions: Data from final analysis of TreatER+ight have further confirmed the evolution to primary use of CDK4/6i-based combination therapy in the first-line setting for Canadian patients with HR+, HER2– ABC. Additional details on duration of therapy by CDK4/6i agents, overall survival data and age subgroup analysis will be presented at SABCS 2023 Table 1_Baseline characteristics, treatment patterns, and duration of treatment Citation Format: Catherine Doyle, Ana Elisa Lohmann, Nayyer Iqbal, Jan-Willem Henning, Swati Kulkarni, Nadia Califaretti, John Hilton, Cristiano Ferrario, Nathaniel Bouganim, Mihaela Mates, Stephanie Guillemette, Ricardo Leite, Stephen Chia. Impact of the introduction of CDK4/6 inhibitors on treatment duration in patients with HR+, HER2– advanced breast cancer: Final analysis of TreatER+ight, a Canadian prospective, real-world, observational study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-17-01.

Abstract PO4-05-08: Primary endocrine therapy resistance in patients with de novo HR+/HER2- metastatic breast Cancer: a National Cancer Information Database Analysis in China

Abstract Background: Endocrine therapy resistance was classifed as primary and secondary, guiding the first-line (1L) treatment choices for hormone receptor positive, HER2-negative (HR+/Her2-) metastatic breast cancer (mBC). However, it is unknown whether it is primary ET resistance or not to the stage IV de novo patients. Therefore, We performed a retrospective study to predict primary resistance in advance in de novo patients and have a more appropriate treatment strategy. Methods: We identified newly diagnosed with stage IV de novo HR+/HER2- mBC patients received single-agent endocrine therapy (ET) or ET plus CDK4/6 inhibitors (CDK4/6i) in 1L setting from January 1, 2020 to Jun 30, 2022, using the National Cancer Information Database (NCID) in China. Primary ET resistance (PER) was defined as switching to second-line treatment within 6 months after receiving the 1L ET±CDK4/6i, whereas secondary ET resistance (SER) patients were those who received 1L ET±CDK4/6i treatment more than six months. The Chi-Square test was used to compare the baseline characteristics of PER and SER patients. Result: A total of 217 patients who met the inclusion criteria were included in the analysis, among which 161 patients received single-agent ET and 56 patients received ET plus CDK4/6i. 18.4% of the patients were classified as PER patients, whereas 81.6% showed SER patients. PER patients were younger (median age of 52 years vs. 58 years in SER patients, p=0.01). In terms of clinicopathological characteristics, patients with PER have a higher percentage of liver metastases (14/40 (35%) vs. 20/177 (11.3%) in SER, p&amp;lt; 0.01), distant lymph node metastases (19/40 (34%) vs. 45/177 (25.4%) in SER, p = 0.01), and bone metastases (30/40(75%) vs. 97/177(54.8%) in SER, p = 0.02). Furthermore, the PER rate was 21.7% (35/161) in patients received single-agent ET, compare with 8.9% (5/56) in ET plus CDK4/6i patients, p=0.04. Regarding the following treatment pattern in the PER patients, a high percentage of patients received chemotherapy, accounting for 50%, 30% still received another endocrine therapy, and the remaining 20% patients received CDK4/6i combined with endocrine therapy. Conclusions: There is still a significant proportion of de novo HR+/HER2- mBC patients with primary endocrine resistance, a relatively low proportion of PER in patients receiving endocrine in combination with CDK4/6i. Table. The proportion of primary endocrine resistance across treatment regimens in de novo HR+/HER2- metastatic breast Cancer Citation Format: Zhanhong Chen, Xiying Shao, Yabing Zheng, Wenming Cao, Junqing Chen, Weizhu Wu, Ting Wang, Xiaojia Wang. Primary endocrine therapy resistance in patients with de novo HR+/HER2- metastatic breast Cancer: a National Cancer Information Database Analysis in China [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-05-08.