Breast Cancer Recurrence Rates Research Articles

P-317 Risk of endometrial polyps and hyperplasia after tamoxifen treatment in women with breast cancer: a population-based study in Taiwan

Abstract Study question This study aimed to examine the association between tamoxifen treatment and incident risks of uterine disease among breast cancer patients in Taiwan. Summary answer We found tamoxifen treatment group may have greater risk of endometrial polyps and hyperplasia than unexposured group after adjusting for age and body mass index. What is known already In the worldwide Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) breast cancer treatment trail reported that the women continue tamoxifen up to 10 years, compared with 5 years may reduce breast cancer recurrence and mortality rate. However, tamoxifen use has been reported to be associated with the cumulative risk of subsequently endometrial cancer during 5–14 years was 3.1%. Specifically, several Western studies have showed that the high incidence of endometrial cancer in breast cancer survivors with tamoxifen treatment. Study design, size, duration We conducted a retrospective cohort study using population-based data from Taiwan Cancer Registry and the National Health Insurance Research Database (NHIRD), and the National Population Registry Data set from 2011 to 2020. Participants/materials, setting, methods A total 138,934 newly diagnosed breast cancer female patients with age greater than 18 years old were included. We further used a 1-to-1 propensity score matching to generate comparable exposure and un-exposure groups. Cox proportional hazard regression models were used to examine the research question. All statistical analysis was performed using SAS version 9.4, and p-values < 0.05 were considered statistically significant Main results and the role of chance Incidence rate ratio (IRR) to compare incidence rate of uterine disease between tamoxifen treatment groups and unexposed group, adjusting for age and BMI. Our results showed that IRR were 1.36, 0.33, 3.73, 0.63, endometrial polyps, endometrial carcinoma, endometrial hyperplasia and uterine carcinosarcoma, respectively. This study found possible correlations between tamoxifen exposure with endometrial polyps and hyperplasia among breast cancer. During the 10-year study period, tamoxifen group did not significantly increase the risk of endometrial cancer in breast cancer survivors at aged 40 and over. Limitations, reasons for caution Our cohort study with 10-year period is its short study period, Tamoxifen group did not significantly increase the risk of endometrial cancer. Wider implications of the findings This cohort study found higher endometrial polyps and hyperplasia incidence rates among women with breast cancer who received tamoxifen women than those not treated with tamoxifen. Results of this study suggest that clinicians should consider the risk of uterine disease among tamoxifen use and counsel patients accordingly. Trial registration number KMUHIRB-G(II)20200217

Breast cancer recurrence rate after mastectomy in young females.

e12591 Background: Breast cancer is the most commonly diagnosed female cancer worldwide and the most common cause of cancer mortality in women. Surgical treatment of early breast cancer includes lumpectomy or mastectomy with or without reconstruction. Despite the surgeon’s best effort to perform a radical resection of the breast tissue during mastectomy to achieve locoregional control, residual fibroglandular tissue was found in 20% of breasts on postoperative breast MRI, which carries a risk of recurrence. Younger women with breast cancer have inferior survival rates despite receiving more aggressive therapy. Tumors in young women are more likely to be poorly differentiated, hormone receptor-negative, have a high proliferation index, and more lymphovascular invasion, which is partially explained by patients’ genetic profile. Another factor that could contribute to poor outcomes is the advanced stage at the time of diagnosis, including larger tumor size and higher rates of axillary lymph node positivity. This knowledge has motivated us to conduct this study that is dedicated to looking at the recurrence rate in young females following mastectomy. Methods: This is a retrospective study that collected data from young female patients who were diagnosed with breast cancer between January 2010 and August 2018, had an age at diagnosis of 18-45 years old, and underwent unilateral or bilateral mastectomy with or without reconstruction. The study also looked at the patient’s risk factors and genetic profile. Results: A total of 115 patients were diagnosed with early-stage breast cancer between January 2010 and August 2018 and underwent mastectomy. 81.74% were Caucasian females, and 8.7% were African American females. The mean age of diagnosis was 36.9 years. The mean BMI was 30.5 kg/m2. 59.13% of patients had a family history of breast cancer. The most common genetic mutations were BRCA1 at 7.83% and BRCA2 at 8.7%. 71% of patients underwent a bilateral mastectomy. 76% of patients had reconstruction. 77% of tumors were ER-positive, 68% PR-positive, and 26% HER2-positive. 49.4% of tumors were Nottingham grade 3. 52% of patients had no nodal involvement, while 35% had N1 disease. 34.6% had lymphovascular invasion. We found that 18/115 patients had recurrence of breast cancer following mastectomy. 5/17 patients had locoregional recurrence, while 12/17 patients had a distant recurrence; 1 patient’s recurrence data was unavailable. The median time to recurrence was 1147.5 days (335 to 3107). The 5-year recurrence free survival rate is 86% ± 3%. Conclusions: Our study found that 15.65% of young females had recurrence after mastectomy. To our knowledge, this is the first dedicated study to look at the recurrence rate after mastectomy in this young, high-risk patient population. Our study aims to encourage larger studies in young females with breast cancer to help tailor the treatment plan in this population.

Impact of semaglutide and tirzepatide administration on weight in women with stage I-III breast cancer.

e24140 Background: Weight gain and obesity are significant problems for women receiving adjuvant therapy for breast cancer and obesity is associated with adverse breast cancer outcomes. In addition, obesity is associated with negative impact on overall physical and mental health. The GLP-1 agonists, semaglutide (S) and tirzepatide (T), are effective in achieving weight loss and have been associated with decreased incidence of diabetes, stroke and overall mortality in the non-diabetic as well as diabetic populations. There are limited data on the efficacy and safety of GLP1 agonists in women with breast cancer. Methods: We performed a retrospective analysis of the association of S and T use with weight loss in patients with stage I-III breast cancer diagnosed and treated at the Yale Cancer Center/Yale New Haven Health Network between 2017 and 2022. After institutional review board approval, a database including 7149 patients including 92,989 office visits was constructed. Maximal weight loss after S/T prescription as well as mean weight loss were calculated. S and T treated patient’s stage distribution and rates of recurrence were compared to untreated patients. For patients without metastatic disease, repeated measures regression analysis was utilized to evaluate changes in weight and BMI. Results: Of the 5430 evaluable patients with non-metastatic disease, 70 (1.3%) were prescribed S or T. Mean age was 58 (41-78). 74% received endocrine therapy. Mean pretreatment weight was 95.8 kg and BMI was 35.9 kg/m2. Mean weight loss for S/T treated patients was 3.03 kg (3.9-2.13, p < .0001) corresponding to reduction in BMI of 1.1 kg/m2 (0.7-1.5 p < .0001). We also calculated maximal weight loss after S/T prescription. Mean maximal weight loss was 8.89 kg (6.71-10.98 P < .0001) corresponding to a mean maximal reduction in BMI of 3.2 kg/m2 (2.3-4.2 P < .0001). Rates of local, locoregional, and distant breast cancer recurrence were 1.5%, 0%, 1.5% in the S/T treated patients and 1.3%, 4.7% and 3.3% in the untreated patients. None of these differences were statistically significant. Conclusions: In this retrospective analysis, GLP-1 agonist are associated with clinically meaningful weight loss in overweight and obese women with early breast cancer. Recurrence risk did not appear to be preliminarily impacted by treatment. Additional research is needed on long term safety as well as weight loss maintenance with these drugs in breast cancer survivors.

A pilot study evaluating exercise intervention and body composition changes in patients with breast cancer and survivors.

e12527 Background: In breast cancer patients and survivors, higher weight and adipose tissue levels have been associated with cardiovascular disease, diabetes, osteoporosis, and cancer recurrence. Additionally, various breast cancer treatments can increase body weight, adipose tissue, and inflammatory markers, raising multiple health concerns for breast cancer patients. Recent studies have found exercise programs alongside breast cancer treatment decreased adipose tissue; however, the weight loss and lifestyle results were not maintained following the exercise program. It remains unclear what strategies are effective in implementing long term lifestyle changes. Methods: In this pilot study, breast cancer patients and survivors (N=24, individual=12, group=12) followed an exercise program for 6 months, followed by 6 months of follow up. Participants ranged from ages 36 to75. Participants were randomized into group and individual exercise sections. Anthropometric measurements were taken at baseline, 3 months and 1 year. One-year measures were used to indicate continued lifestyle changes. Results: Significant differences in fat % body composition were found between baseline and 3 months in both group and individual with an average change of 1.12% (5.9% max) and 1.32% (5.4% max) respectively (P=0.0090). In addition, the baseline and 1-year average change of both group 2.8% (8.8% max) and individual 1.5% (9.6% max) sections was also seen and statistically significant (P=0.0040). Patients in individual and group exercise sections had up to 9.6% and 8.8% decrease in adipose tissue over 1 year, respectively.However, no significant difference was found between the individual and group exercise sections (P=0.3244). Conclusions: Patients from both the individual and group exercise sections continued to decrease adipose tissue composition throughout the 1-year study period, including after formal exercise course cessation at 6 months. This indicates that both group and individual exercise courses may offer similar health benefits to breast cancer survivors. We are continuing long term data collection to evaluate sustainability of the intervention benefits and to monitor breast cancer recurrence rates. Clinical trial information: NCT04013568 . [Table: see text]

Abstract GS02-08: Five-year outcomes of the IDEA trial of endocrine therapy without radiotherapy after breast-conserving surgery for postmenopausal patients age 50-69 with genomically-selected favorable Stage I breast cancer

Abstract Background: Multiple studies have shown a low risk of ipsilateral breast events (IBE) or other recurrences for selected patients age 65-70 or older with Stage I breast cancers treated with breast conserving surgery (BCS) and endocrine therapy (ET) without adjuvant radiotherapy (RT). We designed a prospective single-arm trial, IDEA (Individualized Decisions for Endocrine therapy Alone), to see if younger postmenopausal patients could also be successfully treated without RT, adding a genomic assay to classic selection factors. Methods: Postmenopausal patients aged 50-69 with pT1N0 unifocal invasive breast cancer with margins 2 mm or wider after BCS whose tumors were ER+, PR+, and Her2- with Oncotype DX 21-gene recurrence score (RS) 18 or lower were eligible to avoid RT if they consented to take at least 5 years of ET and surveillance on study. The primary endpoint was the rate of breast cancer recurrence at 5 years of follow-up after BCS. A valid 5–year assessment was defined as a clinical assessment within 4 months prior to the 5-year anniversary or later. Follow-up time was calculated from the date of BCS until first recurrence [ipsilateral breast events (IBE) or regional or distant failures] or to last clinical follow-up. The time-to-event endpoint was calculated using the product-limit method of Kaplan and Meier measured from the date of BCS. Results: 200 eligible patients were enrolled from 13 US institutions between June 2015 and October 2018. Median age was 63 years (IQR 58-66); mean RS was 11.2 (SD 4.8). Tumors were grade 1 in 85 patients, grade 2 in 109, and grade 3 in 6. Mean tumor size was 10 mm (SD 4.6). Lymphovascular invasion was present in 16 tumors and an extensive intraductal component in 11. Median follow-up time was 5.21 years (IQR 5.01-5.97); 8 of 14 patients with less than 56 months of follow-up were lost to follow-up. Overall and breast cancer-specific survival rates at 5 years were both 100%; 2 deaths occurred later than 5 years. The 5-year freedom from recurrence was 99% (95% CI, 96%-100%). One of the two events occurring by 5 years was an isolated axillary recurrence at 21 months treated with axillary dissection and breast and regional nodal irradiation. The other was an IBE at 49 months, treated with repeat BCS. Both these patients had been compliant with ET. Six additional patients recurred later than 5 years after BCS (5 IBEs, 1 IBE plus regional recurrence). Crude rates of IBE for the entire follow-up period for patients aged 50-59 and 60-69 were 3.3% (2/60) and 3.6% (5/140), respectively; crude rates of overall relapse were 5.0% (3/60) and 3.6% (5/140). Conclusions: This multicenter trial of ET without RT following BCS achieved a very low risk of relapse for postmenopausal patients with Stage I cancers using a genomic assay in combination with classic clinical and biologic features for treatment selection, including for patients younger than age 60. IDEA demonstrates a 5-year probability of recurrence consistent with or lower than the 4% risk estimated a priori, and the patients accrued were younger when compared to prior prospective trials (e.g., PRIME II, minimum age 65; CALGB 9343, minimum age 70; LUMINA, median age 67). The results of ongoing NRG BR007 trial, which randomly allocates women meeting these eligibility criteria to receive RT or not, and similar randomized and single-arm studies will help determine whether the option of avoiding initial RT can be offered to a broader group of women than current guidelines recommend. Long-term follow-up beyond the 5-year required period of ET will be important to determine if the risk of recurrence increases, particularly after discontinuation of ET. Citation Format: Reshma Jagsi, Kent Griffith, Eleanor Harris, Jean Wright, Abram Recht, Alphonse Taghian, Lucille Lee, Meena Moran, William Small, Candice Johnstone, Asal Rahimi, Gary Freedman, Mahvish Muzaffar, Bruce Haffty, Kathleen Horst, Simon Powell, Jody Sharp, Michael Sabel, Anne Schott, Mahmoud El-Tamer. Five-year outcomes of the IDEA trial of endocrine therapy without radiotherapy after breast-conserving surgery for postmenopausal patients age 50-69 with genomically-selected favorable Stage I 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 GS02-08.

Abstract PO5-23-05: The Impact of Bi-Annual Diagnostic Imaging on Detecting Ipsilateral Breast Recurrence in Patients Undergoing Breast Conserving Surgery for Breast Cancer

Abstract Introduction: Breast conserving surgery (BCS) represents the preferred option for surgical treatment for a majority of patients with early-stage breast cancer who are eligible for this approach. When compared with mastectomy approaches, BCS provides patients with equivalent survival while preserving the affected breast. It is necessary to achieve clear surgical margins as positive lumpectomy margins are associated with an increased risk for ipsilateral breast tumor recurrence. With advances in imaging techniques, as well as effective systemic therapy and contemporary radiation therapy, local recurrence after BCS has decreased and overall survival for patients has improved. Retrospective studies have quantified the recurrence rate in unifocal breast cancer as 8 - 15% at 20 years. The NCCN recommends annual mammography at least 6 months after post-lumpectomy radiation therapy, but there is little data regarding more frequent surveillance after lumpectomy in the early post-operative setting. The purpose of this study was to evaluate the impact of short interval surveillance mammography on the detection of early in-breast recurrence in patients undergoing BCS. Methods: Our IRB-approved Breast Cancer Database was queried for patients enrolled from 11/2009 to 6/2023 who underwent breast conservation surgery for a diagnosis of in situ or invasive breast cancer in this retrospective analysis. Per our institutional protocol, patients were recommended to undergo diagnostic mammography of the treated breast(s) every 6 months for 2 years after BCS. After the initial 2 year period, bilateral mammography was performed annually in the absence of other indications. Additional supplemental imaging such as breast ultrasound and MRI were performed at physician discretion and based on patient risk and breast density. Variables of interest included the presence of pathogenic germline mutations, family history of breast cancer, and disease characteristics. Our primary endpoint was ipsilateral breast tumor recurrence. Results: Of 2491 patients who underwent breast conservation surgery for in situ or invasive breast cancer, 191 (7.7%) developed recurrent disease, including ipsilateral and contralateral recurrence, and distant disease, in the study period. A total of 83 (3.2%) patients developed ipsilateral breast recurrence during the entire study period. Of those, 19 (22.9%) were detected within the first two years after surgery. Six of the 19 patients (31.6%) had their recurrences detected on yearly diagnostic mammography while 6 (31.6%) patients had their recurrences detected on interval 6-month unilateral diagnostic imaging. In both groups, 5/6 recurrences were invasive disease after an original diagnosis of invasive cancer, and the remaining patient had recurrent DCIS. The remaining 7/19 patients (36.8%) had their ipsilateral recurrences detected on palpation or other diagnostic imaging. In this group as well, there was one case of recurrent DCIS, with the remaining 6 cases representing recurrent invasive cancer. Of the 19 patients with ipsilateral recurrences, none had pathogenic germline mutations. 4 of the 19 patients (21%) had positive margins after their initial lumpectomy surgery with re- excisions required to achieve clear margins. Conclusion: Interval diagnostic surveillance imaging every 6 months after breast conserving surgery identified almost one-third of the ipsilateral breast tumor recurrences that occurred within the first 2 years after surgery in our population. While our numbers are small, the relationship of re-excision lumpectomy surgery to subsequent risk for local recurrence has been described by others, and bears further study. Particularly in view of our observation that the majority of in-breast recurrences were invasive, our data supports the practice of more frequent imaging follow up in the first 2 years after breast conserving surgery. Citation Format: Pabel Miah, Laura Fiedler, Anthony Baez, Athanasios Sevdalis, Alyssa Marmer, Charles DiMaggio, Linda Pak, Richard Shapiro, Karen Hiotis, Deborah Axelrod, Amber Guth, Freya Schnabel. The Impact of Bi-Annual Diagnostic Imaging on Detecting Ipsilateral Breast Recurrence in Patients Undergoing Breast Conserving Surgery for 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 PO5-23-05.

Abstract PO5-11-08: Assessing practice patterns of antidepressant medication and tamoxifen use among patients with hormone receptor-positive breast cancer

Abstract Background: Treatment with endocrine therapy such as tamoxifen has been identified as one of the most important variables linked with survival among women with hormone receptor-positive breast cancer (BC). There is significant risk reduction of BC recurrence and BC mortality at 15 years among patients treated with tamoxifen for 5 years compared to no endocrine therapy. Tamoxifen is metabolized in the liver via multiple cytochrome P (CYP) isoforms. To ensure optimal efficacy of tamoxifen, consideration must be given to concomitant use of other commonly prescribed drugs such as antidepressants. Some selective serotonin reuptake inhibitors (SSRIs) are potent inhibitors of CYP2D6, an enzyme that metabolizes tamoxifen into its active metabolite, endoxifen, which has anti-tumor effect. Such inhibition can reduce the plasma concentration of endoxifen which could lead to higher rates of BC recurrence. This resulted in an FDA black box warning discouraging concurrent prescriptions of tamoxifen and SSRIs, yet clinical data to support this warning is lacking. Our aim is to describe the practice patterns of concomitant use of tamoxifen and antidepressant medication at our institution. Methods: This is a single institution retrospective study that included adult women, ages 18-99, with stage I-IV BC, who received adjuvant tamoxifen and were taking an antidepressant medication between years 2016-2021. Patients were identified from a tumor registry database. Patient demographics and tumor characteristics were collected via electronic medical record. Results: A total of 419 patients met the inclusion criteria. At the start of tamoxifen therapy, 348 women were on at least one antidepressant, mostly for Major Depressive Disorder (86%). Of those women, 22% were prescribed a strong/moderately potent CYP inhibitor (paroxetine, fluoxetine, duloxetine, or bupropion) and 43% were prescribed weak or non-CYP inhibiting SSRIs (citalopram, escitalopram, fluvoxamine, and sertraline). The most commonly prescribed antidepressants at the start of tamoxifen, alone or in combination with a second antidepressant, were: venlafaxine (30%), escitalopram (17%), sertraline (13%), citalopram (12%) and duloxetine (10%). Main prescribers of antidepressants were primary care physicians (70%), psychiatrists (10%) followed by academic medical oncologists (7%) and regional medical oncologists (6%). Interestingly, the majority of women continued taking the same antidepressant after starting tamoxifen (76%) while, at least 10% of patients changed anti-depressant classes prior to starting tamoxifen, due to concern for drug-drug interaction. When a different class of antidepressant was chosen after starting tamoxifen (22%), serotonin and norepinephrine reuptake inhibitors (SNRIs) were the most frequent class (48%), followed by a different SSRI (42%). The time in which the antidepressant change occurred was variable, but most commonly prior to initiating tamoxifen. Conclusion: Concurrent use of tamoxifen and antidepressant medications is common. Theoretical risk of reduced efficacy of tamoxifen with inhibitors of CYP leads to medication changes for some but not all patients requiring tamoxifen and an antidepressant medication. This can have clinical implications as stability on a specific antidepressant is important for patients and adjustment may impact control of their mood disorder. In some cases, even if a drug-drug interaction was identified, some patients chose to continue their current antidepressant due to concerns of mood de-stabilization, and in other cases, aromatase inhibitors were started as an alternative. These findings highlight differences in practice patterns for which additional guidance may be helpful in bringing awareness and standardization to care. Citation Format: Mariah Ondeck, Bennett Osantowski, Nerea Lopetegui-Lia, Wei Wei, Alexandra Murray, Amanda Maggiotto, Halle Moore, Erin Roesch. Assessing practice patterns of antidepressant medication and tamoxifen use among patients with hormone receptor-positive 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 PO5-11-08.

356 The Effect of Regional Anesthesia on Breast Cancer Recurrence

OBJECTIVES/GOALS: To determine the impact of regional anesthesia (RA) on rates of breast cancer recurrence, breast cancer specific mortality, post mastectomy pain syndrome, and chronic opioid use among patients who received regional anesthesia during primary breast cancer surgery. METHODS/STUDY POPULATION: Study population: Patients who underwent primary breast cancer surgery at Emory University and among a national patient cohort. Methods: This is a retrospective analysis of patients who underwent primary breast cancer surgery. Invasive breast cancer specific survival & breast cancer-specific survival will be estimated using Kaplan-Meier method and compared among patient groups. Cox proportional hazards will be utilized to estimate the unadjusted & adjusted risk of breast cancer recurrence and breast cancer-specific mortality between the two groups. RESULTS/ANTICIPATED RESULTS: We will present on our work comparing rates of breast cancer recurrence among patients who received regional anesthesia compared to patients who did not. DISCUSSION/SIGNIFICANCE: This study aims to establish the effect of regional anesthesia on breast cancer recurrence,breast cancer specific mortality, post mastectomy pain syndrome, and chronic opioid use following primary breast cancer surgery.

Abstract 3474: Racial disparities in receipt of surveillance mammography after breast cancer diagnosis

Abstract Background: The 5-year survival rate for breast cancer (BC) stands at an estimated 91%, with approximately 3.8 million BC survivors in the U.S. This large population of breast cancer survivors remains at risk of loco-regional recurrence, with variations noted across racial groups. White survivors face a locoregional breast cancer recurrence rate of 1.8%, whereas Black, Asian, and Hispanic survivors experience higher rates of 3.9%, 3.6%, and 3.1%, respectively. Notably, Black BC survivors with recurrent breast cancer exhibit a median survival time of 1.8 years compared with 3.6 years observed for White BC survivors. Current recommendations from the U.S. Preventative Services Task Force and the American College of Radiology advocate for surveillance through annual mammography and routine clinical visits following breast-conserving surgery and lumpectomies. However, there are gaps in the data available regarding disparities in the utilization of surveillance mammography by race/ethnicity. Thus, the goal of this study is to estimate race/ethnic disparities in surveillance mammography utilization and its impact on survival among breast cancer survivors at a large comprehensive cancer center. Methods: A retrospective cohort study of female breast cancer survivors ≥19 years diagnosed and/or treated at the Duke Cancer Institute (DCI) between 2014 and 2022 was conducted. Data was abstracted on patient socio-demographics, cancer type (invasive ductal and ductal in situ carcinomas) and utilization of surveillance mammography within 2-5 years post initial breast cancer diagnosis. Chi-squared testing will be used to analyze rates of mammography surveillance receipt among different races presenting with BC at DCI. Kaplan-Meier estimates will be used for analysis on survival. Results: A total of 10,904 women with a mean age of 43.7 years were included in the study. The study cohort is comprised of 69% non-Hispanic (NH) White, 24% NH Black, 2.2% Hispanic, 0.5% NH Native American, 1% NH other, and 3.2% NH Asian women. There were 1,791 cases of ductal in situ carcinomas and 9,113 invasive ductal carcinoma cases. NH Black women had the lowest 5-year relative survival rate (81.5%) of all represented racial groups: NH White 89.1%, Hispanic 95.3%, NH Native 87.8%, Asian 97.9%, and NH Other 88.0%. Ongoing analysis will be completed to estimate disparities in the use of post-treatment surveillance mammography amongst breast cancer survivors. Conclusions: This study will inform efforts to increase post-treatment surveillance and improve adherence to survivorship guidelines with the ultimate goal of reducing mortality disparities among breast cancer survivors. Citation Format: Jasmine G. Wilkerson, Frances Wang, Yadurshini Raveendran, Tomi Akinyemiju. Racial disparities in receipt of surveillance mammography after breast cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3474.

The association between complementary and alternative medicine use with breast cancer recurrence in Taif city, Saudi Arabia

Background: Breast cancer (BC) is the most common cancer among women worldwide. Among all types of cancer, 11.7% of cases diagnosed in 2020 were BC. Compare this to Saudi Arabia, where 28.8 out of every 100,000 women were diagnosed with BC. Furthermore, BC patients are more likely than other cancer survivors to use complementary and alternative medicine (CAM). Study aimed to investigate association between CAM use and BC recurrence rates in Saudi Arabia. Methods: A cross-sectional study was conducted on 106 participants recruited from breast surgery clinics. Targeted women were diagnosed with BC and treated at Al Hada armed forces hospital. The data were collected by interviewing the patients using a validated questionnaire. Results: The prevalence of CAM usage among BC patients was 35.8%. The recurrence rate of BC was 26.4%. CAM users accounted for 28.57% of the total, while non-CAM users comprised 71.43%. In addition, 50% of recurrences were distant metastases, and 50% occurred more than two years after diagnosis. Conclusions: In conclusion, more than one-third of BC patients in this region incorporate CAM into their treatment regimen. Our findings reveal a practical but not statistical significance of a lower recurrence rate of BC among CAM users compared to non-CAM. These results emphasize the importance of healthcare providers engaging in detailed discussions with BC patients regarding CAM usage in conjunction with planned medical and surgical therapies.

Increased risk of contralateral breast cancer for BRCA1/2 wild-type, high-risk Korean breast cancer patients: a retrospective cohort study

BackgroundThis study aimed to investigate the contralateral breast cancer (CBC) recurrence rate in Korean breast cancer patients according to their BRCA1/2 germline mutation status, focusing particularly on the CBC recurrence risk in BRCA1/2 negative (BRCAx) patients.MethodsWe conducted a retrospective study on 13,107 primary breast cancer patients. The patients were divided into high-risk and low-risk groups for hereditary breast cancer based on the Korean National Health Insurance Service’s eligibility criteria for BRCA1/2 germline mutation testing. The high-risk group was further categorized into the BRCAmutation group, the BRCAxgroup, and the not tested group. We evaluated the overall survival and cumulative risk of developing CBC in these patients.ResultsAmong 4494 high-risk patients, 973 (21.7%) underwent genetic testing for BRCA1/2 germline mutation, revealing mutations in 158 patients (16.2%). We observed significant overall survival differences across all four groups, with the high-risk, not-tested group demonstrating notably worse overall survival (p < 0.001). However, when adjusted for other prognostic factors, there was no significant differences in hazard ratio of death between the four groups. The cumulative risk of CBC also varied among the groups. Patients with BRCA1/2 mutations showed a 7.3-fold increased risk of CBC compared to the low-risk group (95% CI 4.11–13.0, p < 0.001). Interestingly, BRCAx patients also demonstrated a significantly higher risk of CBC (HR 2.77, 95% CI 1.76–4.35, p < 0.001). The prognostic importance of the BRCAx for CBC recurrence persisted after adjusting for the age and subtype, but became insignificant when the family history of breast cancer was adjusted.ConclusionBreast cancer patients who are at high risk of hereditary breast cancer but with wild-type BRCA 1/2 genes (BRCAx) have increased risk of developing contralateral breast cancer when compared to the low-risk patients. More careful surveillance and follow-up can be offered to these patients especially when they have family history of breast cancer.

Based on whole-exome sequencing to explore the rule of Herceptin and TKI resistance in breast cancer patients

BackgroundBreast cancer is the second leading cause of cancer-related death in women, and drug resistance during treatment is a major challenge. However, the mechanisms underlying drug resistance are not fully understood. Here we applied whole-exome sequencing (WES) to clarify resistant rules to Herceptin and tyrosine kinase inhibitors (TKIs).MethodsThere are 12 HER2+ breast cancer patients who were done WES. Samples from tumor and surrounding tissues underwent DNA sequencing and analysis. Various experimental and bioinformatics techniques were employed, including genomic capture, mutation analysis (Genome Analysis Toolkit (GATK), etc.), bioinformatics assessments, and drug-gene interaction investigations. Ultimately, the study explored the association of APOB gene expression with breast cancer recurrence rates, immune cell infiltration, and drug response.ResultsThe C > T mutation frequency was highest in the Herceptin-insensitive (HI) and verification groups, codenamed YI, contrasting with the Herceptin-sensitive (HE) group. No microsatellite instability (MSI)-H patients were in the HE group, but both HI and YI groups had 1 each. Significant differences in transition-transversion (TiTv) were observed in the HI and YI groups rather than the HE group. In the TKI- insensitive (TI) group, C > T mutations were highest, differing from the TKI-sensitive (TE) group. TE group included 2 MSI-H patients. Significant differences in TiTv were found in the TI group rather than the TE group. Mutated APOB may resist Herceptin and TKI, increasing immune infiltration. We identified potential drugs targeting it.ConclusionsOur study suggested that a higher percentage of C > T mutations, significant differences in TiTv, and MSI-H status may indicate Herceptin resistance, while a higher percentage of C > T mutations, significant differences in TiTv, and the absence of MSI-H may indicate TKI resistance in breast cancer patients. For patients resistant to both Herceptin and TKI, mutated APOB may play a crucial role in resistance.

Metal-Organic Framework-Based Nano-Activators Facilitating Microwave Combined Therapy via a Divide-and-Conquer Tactic for Triple-Negative Breast Cancer.

Aiming at the clinical problems of high recurrence and metastasis rate of triple-negative breast cancer, a divide-and-conquer tactic is developed. The designed nanoactivators enhance microwave thermo-dynamic-chemotherapy to efficiently kill primary tumors, simultaneously ameliorate the immunosuppressive microenvironment, activate the tumor infiltration of T lymphocytes, and enhance the accumulation and penetration of PD-1/PD-L1 immune agents, ultimately boosting the efficacy of immune checkpoint blocking therapy to achieve efficient inhibition of distal tumors and metastases. Metal-organic framework (MOF)-based MPPT nano-activator is synthesized by packaging chemotherapeutic drug Pyrotinib and immunosuppressant PD-1/PD-L1 inhibitor 2 into MnCa-MOF and then coupling target molecule triphenylphosphine, which significantly improved the accumulation and penetration of Pyrotinib and immunosuppressant in tumors. In addition to the combined treatment of microwave thermo-dynamic-chemotherapy under microwave irradiation, Mn2+ in the nano-activator comprehensively promotes the cGAS-STING pathway to activate innate immunity, microwave therapy, and hypoxia relief are combined to ameliorate the tumor immunosuppressive microenvironment. The released Pyrotinib down-regulates epidermal growth factor receptor and its downstream pathways PI3K/AKT/mTOR and MAPK/ERK signaling pathways to maximize the therapeutic effect of immune checkpoint blocking, which helps to enhance the antitumor efficacy and promote long-term memory immunity. This nano-activator offers a generally promising paradigm for existing clinical triple-negative breast cancer treatment through a divide-and-conquer strategy.

Assessing the impact of frequent mammography after breast cancer treatment from a single-institution retrospective analysis

Background Despite prior attempts to establish guidelines, many radiologists still recommend frequent (every six month) mammography after breast conserving surgery. Ideally this recommendation would be based on the incremental value (recurrences detected earlier) of non-annual screening, compared to the associated harm (from false positive results leading to patient distress, unnecessary biopsies/procedures and costs). The aim of this study was to analyze the outcomes of performing biannual mammograms at our institution in order to determine if this may provide any additional benefit to annual mammograms. Methods A retrospective analysis of 359 female patients with stage 0-III breast cancer who underwent breast-conservation surgery was performed. Data were obtained on breast cancer characteristics, imaging, pathology, and recurrence rates. Descriptive analyses were subsequently performed. Results A total of 569 6-month and 18-month mammograms were completed after breast-conservation therapy. This led to 22 biopsies, only one of which detected a recurrence (in a high-risk patient who was unable to complete recommended treatment). Conclusions The data suggest that annual surveillance mammography following breast conserving therapy (BCT) is likely sufficient for detection of recurrences, with increased screening leading to increased harm without benefit. More frequent screening should be limited to select high-risk patients.

A Biosignature Integrating Immune and Metabolic Signaling Axes to Assess Limited Radiation Therapy Response in Early-Stage Breast Cancer from a Low-Risk Cohort

Radiation therapy (RT) post breast conserving surgery (BCS) reduces in-breast recurrence (IBR) rate in early-stage invasive breast cancer (BC) patients. The RT treatment recommendation is often driven by clinicopathological (CP) factors; however, CP factors alone have limited ability to identify which women significantly benefit from RT, or those with higher IBR risk after BCS plus RT. Biologic factors driving unique phenotypes, in addition to CP, may improve prediction of RT response. In this study we evaluated the role of immune and metabolic signaling axes in predicting RT response in hormone receptor positive, HER2 negative, early-stage BC patients. Biomarkers from immune and metabolic signaling axes were studied in a cohort of 939 women from Sweden, at a CLIA certified lab (Laguna Hills, CA). Formalin fixed paraffin embedded tissues were assayed for protein expression using multiplex immunofluorescence and multi-spectral imaging. Immune and metabolic axes were assessed using biomarkers combined with a non-linear model, adjusting for patient age. RT prediction by the model was assessed, along and adjusted for CP factors and also among patients over 50-yrs. The model defined patient risk groups that were analyzed for IBR rate using Kaplan Meier analyses and Cox proportional hazards to test for RT-risk group interaction. Within the cohort, 440 patients had hormone receptor positive, HER2 negative BC treated with BCS (negative margins) and +/- RT without chemotherapy, where 296 patients had complete biomarker data. CP factors individually were not predictive for RT benefit, but grade was prognostic for IBR rate (p = 0.02) after BCS without RT. In multivariable analysis, adjusting for CP factors (grade, palpability, continuous size and age), the model was predictive for RT benefit (p-interaction = 0.046), identifying patients (n = 129) with worse RT benefit (HR = 7.8) compared to baseline RT benefit. The model was not prognostic for IBR rate in patients treated with BCS without RT (16% 10-yr IBR rate) but identified patients with increased IBR rates after BCS plus RT (HR = 3.9, p<0.001), where corresponding 10-yr IBR rates increased from 3% to 15%. The model was also predictive for RT benefit in women over 50-yrs (p-interaction = 0.05). The model identified 28% of women over 50-yrs who had increased IBR rates after BCS plus RT (HR = 4.0, p = 0.004), where corresponding 10-yr IBR rates increased from 3% to 12%. The model incorporating metabolic and immune signaling axes assessed in the study was predictive for RT benefit among women with early-stage hormone receptor positive, HER2 negative BC. While CP factors were not predictive of RT benefit, the inclusion of metabolic and immune signaling axes improved identification of patients with high residual risk after BCS plus RT and can potentially aid in personalized treatment of early-stage breast cancer based on individualized risk.

The worldwide impact of HER2-targeted treatments in women with breast cancer: An epidemiological modeling study.

543 Background: HER2-targeted therapies (trastuzumab, pertuzumab, and T-DM1) have revolutionized the treatment and epidemiological landscape of HER2+ breast cancer, resulting in population-level increases in survival and decreases in disease recurrence. The aim of this epidemiological modeling study was to quantify the estimated global impact of HER2-targeted therapies, by estimating the number of women diagnosed with HER2+ early breast cancer (eBC) who have avoided (or will avoid) metastatic disease recurrence following treatment. Methods: We used data and projections from cancer registries, observational studies, clinical trials, and drug sales volumes (ie, utilization) to create annual country-level synthetic cohorts of patients diagnosed with HER2+ eBC, for the years 2004-2033 in 185 countries. The real-world uptake of HER2-targeted treatments and treatment flow was estimated in the main scenario. The impact of chemotherapy alone was estimated in the counterfactual scenario, assuming 100% chemotherapy worldwide. The occurrence of distant recurrences was modeled in both scenarios using weighted transitional probability averages based on invasive disease-free survival curves from clinical trials. Results: In total, during the 3-decade study period, we predicted that 11.9 million (M) women would be diagnosed with HER2+ eBC, out of which 7.5M were estimated to be treated with HER2-targeted therapies in a real-world uptake scenario. In the counterfactual scenario with only chemotherapy available, a total of 2.9M women were estimated to experience a metastatic disease recurrence, compared to only 2.1M women in the base scenario of predicted real-world uptake of HER2+ targeted therapies. This corresponds to a reduction of 26% or 768,000 women who may avoid metastatic recurrence since the introduction of HER2-targeted therapies (Table). Conclusions: HER2+ targeted therapies have substantially improved breast cancer outcomes and continue to contribute to the reduction in breast cancer recurrence rates. Further research may elucidate treatment-related reductions in costs to society as a result of population-level improvements in disease outcomes for breast cancer survivors. Given the expected rise in the burden of breast cancer globally, therapeutic advances and increased treatment utilization may further accelerate global patient benefit. [Table: see text]

Breast cancer-related lymphedema and recurrence of breast cancer: Protocol for a prospective cohort study in China.

The primary aim is to determine the factors associated with breast cancer-related lymphedema and to identify new associated factors for the recurrence of breast cancer and depression. The secondary objective is to investigate the incidence of breast cancer-related events (breast cancer-related lymphedema, recurrence of breast cancer, and depression). Finally, we want to explore and validate the complex relationship among multiple factors influencing breast cancer complications and breast cancer recurrence. A cohort study of females with unilateral breast cancer will be conducted in West China Hospital between February 2023 and February 2026. Breast cancer survivors in the age range of 17-55 will be recruited before breast cancer surgery. We will recruit 1557 preoperative patients with a first invasive breast cancer diagnosis. Consenting breast cancer survivors will complete demographic information, clinicopathological factors, surgery information, baseline information, and a baseline depression questionnaire. Data will be collected at four stages: the perioperative stage, chemotherapy therapy stage, radiation therapy stage, and follow-up stage. Data including the incidence and correlation of breast cancer-related lymphedema, breast cancer recurrence, depression, and medical cost will be collected and computed through the four stages above. For every statistical analysis, the participants will be classified into two groups based on whether they develop secondary lymphedema. Incidence rates of breast cancer recurrence and depression will be calculated separately for groups. Multivariate logistic regression will be used to determine whether secondary lymphedema and other parameters can predict breast cancer recurrence. Our prospective cohort study will contribute to establishing an early detection program for breast cancer-related lymphedema and recurrence of breast cancer, which are both associated with poor quality of life and reduced life expectancy. Our study can also provide new insights into the physical, economic, treatment-related and mental burdens of breast cancer survivors.

AB044. SOH23ABS_117. Value of the 21-gene expression assay in predicting locoregional recurrence rates in estrogen receptor positive breast cancer: a systematic review and network meta-analysis

AB044. SOH23ABS_117. Value of the 21-gene expression assay in predicting locoregional recurrence rates in estrogen receptor positive breast cancer: a systematic review and network meta-analysis

Abstract P4-03-18: Group-based trajectories of endocrine therapy adherence and risk of recurrence in a Danish premenopausal breast cancer cohort

Abstract Background: Adjuvant endocrine therapy (AET) approximately halves the risk of recurrence among the two-thirds of premenopausal breast cancer patients whose tumors overexpress the estrogen receptor (ER+). AET is recommended for a minimum five-year duration, but many premenopausal women discontinue AET prematurely. Adherence to AET is dynamic and influenced by many behavioral, societal, clinical, and genetic factors. Describing longitudinal patterns of AET adherence is an important first step towards identifying patients at highest risk of nonadherence–-and therefore recurrence–-who may benefit from adherence-enhancing interventions. We used group-based trajectory models to (1) describe AET adherence patterns, and (2) estimate associations between AET adherence and breast cancer recurrence in a Danish premenopausal, ER+ breast cancer cohort. Methods: Our cohort included 4,487 premenopausal women diagnosed with ER+, stage I–III primary breast cancer registered in the Danish Breast Cancer Group (DBCG) clinical database and treated with AET (2002–2011). We followed all patients from initiation of AET until recurrence, mortality, 10 years of follow-up, another primary malignancy, or the end of available follow-up. We excluded individuals with less than 1.5 years of follow-up as breast cancer recurrences that occur in this time are unlikely to be related to AET. At semi-annual follow-up visits, women were registered as having received (or not) a six-month supply of AET. We created daily indicators to determine if a woman had at least 80% of days covered by an AET fill within each six-month period for the first 4.5 years following AET initiation, yielding 9 variables indicating time-varying adherence. We used these indicators to characterize adherence trajectory groups. We defined recurrence as local, regional or distant metastases or contralateral breast cancer registered in the DBCG using follow-up data through 2017. We fit Cox regression models, adjusted for age and clinical factors, to estimate the association between adherence trajectory groups and recurrence. Results: We identified distinct trajectory groups in the cohort (Table 1)—high adherence (69%), slow decline (23%), and quick decline (8%). Women with quick decline were more likely to have stage I disease, have no positive lymph nodes, to not be treated with chemotherapy, and to have lumpectomy instead of mastectomy when compared to women with high adherence. Compared with high adherence women, the estimated rate of breast cancer recurrence was higher among those with slow decline (HR=1.12, 95%CI=1.04–1.21) and those with quick decline (HR=1.38, 95%CI=1.22–1.56). Conclusions: Group-trajectory modeling facilitated empirical description of AET adherence patterns in a premenopausal breast cancer cohort. As expected, women who more rapidly became AET-nonadherent were at increased risk of breast cancer recurrence compared with those who remained adherent. Future analyses will explore the contribution of specific socioeconomic, genetic, and clinical factors to AET adherence patterns, which will inform the design of interventions to improve AET adherence and reduce recurrence risk in breast cancer patients. Table 1. Trajectory group and the observed proportion of individuals adherent to their adjuvant endocrine therapy (AET) over 4.5 years of follow-up Citation Format: Kirsten M. Woolpert, Julie A. Schmidt, Thomas P. Ahern, Timothy L. Lash, Lindsay J. Collin, Bent Ejlertsen, Deirdre Cronin-Fenton. Group-based trajectories of endocrine therapy adherence and risk of recurrence in a Danish premenopausal breast cancer cohort [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-18.

Effectiveness of Prophylactic Mastectomy

Introduction: The growing incidence and recurrence rate of breast cancer has influenced multiple strategies such as surgical interventions that serve as preventive measures for women at high risk. Prophylactic mastectomy seems to be the most effective tool in the primary prevention of breast cancer, but opinions are not uniform, especially among specialists. The goal of this presentation is to examine the effect of risk-reducing mastectomy, including breast cancer incidence, breast cancer mortality, disease-free survival, physical morbidity, and psychosocial outcomes in cohort of patients who underwent prophylactic mastectomy. Materials and Methods: We retrospectively reviewed the outcomes of 20 years of experience with prophylactic mastectomies performed at the department from 1999 to 2019. In this study were included patients who underwent bilateral prophylactic mastectomy with no breast cancer, and patients with breast cancer, if they underwent contralateral risk-reducing mastectomy, however, only the prophylactic side was considered in the analysis. Patients with bilateral breast cancer were excluded. Results: A total of 749 risk-reducing prophylactic mastectomy in 545 patients were performed at our department from 1999 to 2019. Bilateral prophylactic mastectomies were performed in 204 patients (37,4%), and 341 (62,6%) underwent a unilateral risk-reducing mastectomy secondary to cancer in the contralateral breast. Overall, 243 patients with BRCA1 mutations and 113 with BRCA2 mutations were included. Conclusion: Prophylactic mastectomy is highly preventive against breast cancer. Although further clinical studies are needed to determine the effectiveness of prophylactic mastectomies in individual indications. With the effectiveness of prophylactic mastectomy should also be taken into consideration the quality of life after the immediate breast reconstruction, and the associated complications.