Receptor-positive Human Epidermal Growth Factor Research Articles

Treatment and survival of patients diagnosed with high-risk HR+/HER2− breast cancer in the Netherlands: a population-based retrospective cohort study

Several factors may increase the risk of recurrence of patients diagnosed with hormone receptor-positive human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer (BC). We aim to determine the proportion of patients with high-risk HR+/HER2- BC within the total HR+/HER2- BC cohort and compare their systemic treatments and survival rates with those of patients with low- and intermediate-risk HR+/HER2- BC and triple-negative (TN) BC. Women diagnosed with nonmetastatic invasive HR+/HER2- BC and TNBC in the Netherlands between 2011 and 2019 were identified from the Netherlands Cancer Registry. Patients with HR+/HER2- BC were categorised according to risk profile, defined by nodal status, tumour size, and histological grade. High-risk HR+/HER2- BC was defined by either four or more positive lymph nodes or one to three positive lymph nodes with a tumour size of ≥5 cm or a histological grade 3 tumour. Overall survival (OS) and relative survival (RS) were calculated using the Kaplan-Meier and Pohar-Perme method. In this study of 87 455 patients with HR+/HER2- BC, 44 078 (50%) patients were diagnosed with low risk, 28 452 (33%) with intermediate risk, and 11 285 (13%) with high-risk HR+/HER2- BC. In 3640 (4%) patients, the risk profile could not be defined. Endocrine therapy and chemotherapy were used in 38% and 7% of low-risk, 90% and 47% of intermediate-risk, and 94% and 73% of high-risk patients, respectively. The 10-year OS and RS rates were 84.1% [95% confidence interval (95% CI) 83.5% to 84.7%] and 98.7% (95% CI 97.3% to 99.4%) in low-risk, 75.1% (95% CI 74.2% to 76.0%) and 91.7% (95% CI 89.7% to 93.3%) in intermediate-risk, and 63.4% (95% CI 62.0% to 64.7%) and 72.3% (70.1% to 74.3%) in high-risk patients. The 10-year OS and RS rates of 12 689 patients with TNBC were 69.7% (95% CI 68.6% to 70.8%) and 79.1% (95% CI 77.0% to 80.9%), respectively. The poor prognosis of patients with high-risk HR+/HER2- BC highlights the need for a better acknowledgement of this subgroup and supports ongoing clinical trials aimed at optimising systemic therapy.

Consensus on the clinical use of CDK4/6 inhibitors for the treatment of hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer (2023 edition)

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have led transformative breakthrough of clinical therapy for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER-2)-negative breast cancer patients. CDK4/6 inhibitors that have been marketed in China include Ribociclib, Palbociclib, Abemaciclib and Dalpiciclib. For HR-positive HER-2-negative locally advanced and metastatic breast cancer, CDK4/6 inhibitors combined with endocrine therapy have become standard regimen, which can prolong the survival of patients. In the adjuvant treatment stage of early breast cancer, CDK4/6 inhibitors have also achieved positive results and been approved for indications. At present, CDK4/6 inhibitors have been widely used in clinical practice in China. In order to further improve the standardized application of CDK4/6 inhibitors in China, the Breast Cancer Expert Committee of the National Center for Cancer Quality Control and the Professional Committee of Clinical Research of Cancer Drugs of the Chinese Anti-Cancer Association organized the related expert to update the consensus based on the "CDK4/6 inhibitor consensus on clinical application of in the treatment of hormone receptor positive human epidermal growth factor receptor 2 negative advanced breast cancer (2021 edition)" . The updated consensus systematically introduces the pharmacological characteristics, drug monitoring and adverse event management, etc., of CDK4/6 inhibitors to promote the accuracy of clinical decision-making with the ultimate goal to prolong the overall survival of patients and improve the quality of life.

Efficacy and safety of tucidinostat in patients with advanced hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer: real-world insights.

Tucidinostat, which is a subtype-selective histone deacetylase inhibitor, has been approved in China for the treatment of hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). However, existing evidence mainly stemmed from randomized controlled trials, and might have limitations in representing the complexities of clinical practice and diverse patient populations. Therefore, there is a need to explore the efficacy and optimal therapeutic modality for tucidinostat in real-world clinical settings. The objective of this real-world study was to analyze the clinical data of 47 patients with HR+/HER2- ABC who received tucidinostat treatment at West China Hospital, Sichuan University, between August 2020 and May 2023. The primary outcomes were progression-free survival (PFS) and clinical benefit rate [CBR; defined as partial response (PR) and stable disease (SD) for ≥6 months on clinical evaluation]. A total of 47 patients were included, and the median follow-up time was 18.20 months. The median line of tucidinostat therapy was 3 (range, 1-9). In all, 52.17% patients were treated with tucidinostat plus fulvestrant, while 38.30% were treated with tucidinostat plus aromatase inhibitors. Notably, 10.64% of the patients with rapidly progressing visceral metastases received tucidinostat plus endocrine therapy as maintenance treatment after achieving disease control with chemotherapy. The median PFS was 4.43 months [95% confidence interval (CI), 2.77-10.53], and the median overall survival was 19.57 months (95% CI, 12.83-not reached). The 6-month CBR for the overall population was 41.86%. Patients undergoing maintenance therapy demonstrated a significantly longer PFS than did those who did not receive it as maintenance therapy (14.13 vs. 3.93 months; P=0.01). Univariate Cox regression analysis showed that use of tucidinostat in lines 1-2, use of tucidinostat plus fulvestrant, presence of one metastatic site, and lack of brain metastasis were favorable factors for PFS. Thrombocytopenia was the most frequently reported adverse event, with an incidence rate of 31.91% at all grades and 14.89% at grade ≥3. Four (8.51%) patients discontinued the treatment. For patients with HR+/HER2- ABC, tucidinostat combination therapy offers certain survival benefits with controllable safety. Furthermore, compared with non-maintenance therapy, maintenance therapy after chemotherapy may have promising efficacy.

461P Impact of comorbidities on real-world patient-reported outcomes of patients (pts) with hormone receptor-positive human epidermal growth factor 2-negative (HR+/HER2-) advanced breast cancer (ABC) enrolled in the POLARIS trial

461P Impact of comorbidities on real-world patient-reported outcomes of patients (pts) with hormone receptor-positive human epidermal growth factor 2-negative (HR+/HER2-) advanced breast cancer (ABC) enrolled in the POLARIS trial

Optimal treatment strategy for hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer patients with 1-2 suspicious axillary lymph node metastases on breast magnetic resonance imaging: upfront surgery vs. neoadjuvant chemotherapy.

It is unclear whether upfront surgery or neoadjuvant chemotherapy is appropriate for first treatment in hormone receptor (HR)-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients with 1-2 suspicious axillary lymph node (ALN) metastases on preoperative breast magnetic resonance imaging (MRI). We identified 282 patients with HR+HER2- breast cancer and 1-2 suspicious ALN metastases on baseline breast MRI (147 received upfront surgery; 135 received neoadjuvant chemotherapy). We evaluated the predictive clinicopathological factors for pN2-3 in the adjuvant setting and axillary pathologic complete response (pCR) in the neoadjuvant setting. Lymphovascular invasion (LVI)-positive and clinical tumors >3cm were significantly associated with pN2-3 in patients who received upfront surgery. The pN2-3 rate was 9.3% in patients with a clinical tumor ≤ 3cm and LVI-negative versus 34.7% in the others (p < 0.001). The pN2-3 rate in patients with a clinical tumor ≤ 3cm and LVI-negative and in the others were 9.3% versus 34.7% in all patients (p < 0.001), 10.7% versus 40.0% (p = 0.033) in patients aged < 50 years, and 8.5% versus 31.0% in patients aged ≥ 50 years (p < 0.001), respectively. In the neoadjuvant setting, patients with tumor-infiltrating lymphocytes (TILs) ≥ 20% had a higher axillary pCR than those with TILs < 20% (46.7% vs. 15.3%, p < 0.001). A similar significant finding was also observed in patients < 50 years. Upfront surgery may be preferable for patients aged ≥ 50 years with a clinical tumor < 3cm and LVI-negative, while neoadjuvant chemotherapy may be preferable for those aged < 50 years with TILs ≥ 20%.

105P Real-world systemic treatment choices and survival outcomes of patients diagnosed with non-metastatic high-risk HR+/HER2- breast cancer in the Netherlands

This study determines the proportion of patients with high-risk hormone receptor-positive human epidermal growth factor receptor-2-negative (HR+/HER2-) breast cancer (BC) within the total cohort of patients with non-metastatic HR+/HER2- BC and compares their systemic treatments and survival rates with those of patients with low- and intermediate-risk HR+/HER2- BC and triple-negative (TN) BC. All women (≥18 years) diagnosed with non-metastatic invasive HR+/HER2- BC or TNBC in the Netherlands between 2011 and 2019 were identified from the Netherlands Cancer Registry. Patients with HR+/HER2- BC were classified as low-, intermediate-, or high-risk, based on the number of positive lymph nodes, tumour size, and histological grade. Overall survival (OS) was evaluated using Kaplan-Meier survival analyses. Relative survival (RS) was estimated with the Pohar Perme method and defined as the ratio between OS and the expected survival of the Dutch population, using data from Statistics Netherlands. Survival data were available up to January 31, 2022. This study included 86,522 patients with HR+/HER2- BC. Of these, 51% had low-risk, 32% had intermediate-risk, and 13% had high-risk disease. In 4% of patients, the risk profile could not be defined. Endocrine therapy and chemotherapy use increased with an increasing risk classification: from 38% and 7% in low-risk, and 90% and 47% in intermediate-risk patients to 94% and 73% in high-risk patients. The 10-year OS and RS (95% confidence interval) were 84.2% (83.6-84.7) and 97.7% (96.8-98.4) in low-risk, 75.4% (74.5-76.2) and 92.4% (90.9-93.6) in intermediate-risk, and 64.4% (63.0-65.7) and 72.6% (70.8-74.3) in high-risk patients. The 10-year OS and RS of 12,448 patients with TNBC were 70.5% (69.4-71.6) and 78.3% (76.7-79.8), respectively. This study shows that 13% of patients with non-metastatic HR+/HER2- BC had high-risk disease. Although the majority of these patients received endocrine therapy and chemotherapy, the 10-year OS and RS rates were low and even worse than those of patients with TNBC. These data indicate an unmet medical need for modification of systemic treatment in this subgroup of patients.

Development and Validation of a Quantitative LC-MS/MS Method for CDK4/6 Inhibitors Palbociclib, Ribociclib, Abemaciclib, and Abemaciclib-M2 in Human Plasma.

The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, palbociclib, ribociclib, and abemaciclib, are standard-of-care agents for patients with hormone receptor-positive human epidermal growth factor receptor 2-negative metastatic breast cancer. In support of therapeutic drug monitoring and clinical pharmacokinetic studies, a liquid chromatography coupled with tandem mass spectrometry assay for the simultaneous quantitation of CDK4/6 inhibitors and the major active metabolite M2 of abemaciclib in human plasma has been developed. Analytes were extracted from 50 μL of human plasma by precipitating proteins with methanol and then collecting the supernatant. Reversed-phase high-performance liquid chromatography was performed for analyte separation using a biphasic gradient at a flow rate of 0.25-0.5 mL/min. The total run time was 9.5 minutes. The analytes were detected using MS/MS with electrospray ionization operating in positive ion mode. Validation according to the US Food and Drug Administration's guidance showed that the new assay produced accurate (94.7%-107%) and precise (within-run: 1.2%-8.2%; between-run: 0.6%-7.5%) measurements of all analytes over a concentration range of 5-2000 ng/mL. Overall, analyte recoveries were consistent (mean values: 110%-129%). The analytes were also stable in human plasma and the final extract under various storage conditions. Finally, the clinical applicability of the assay was confirmed by quantitation of all analytes in plasma samples obtained from patients treated with CDK4/6 inhibitors. Reproducibility of the measured analyte concentrations in study samples was confirmed successfully by incurred sample reanalysis. A sensitive liquid chromatography coupled with tandem mass spectrometry method to measure CDK4/6 inhibitors was developed and validated according to the Food and Drug Administration criteria. Quantitation of all analytes in clinical plasma samples confirmed that the assay is suitable for therapeutic drug monitoring and clinical pharmacokinetic studies of CDK4/6 inhibitors.

Breast Cancer Statistics in Korea, 2019.

This article provides an annual update of Korean breast cancer statistics, including the incidence, tumor stage, type of surgical treatment, and mortality. The data was collected from the Korean Breast Cancer Society registry system and Korean Central Cancer Registry. In 2019, 29,729 women were newly diagnosed with breast cancer. Breast cancer has continued to increase in incidence since 2002 and been the most common cancer in Korean women since 2019. Of the newly diagnosed cases in 2019, 24,820 (83.5%) were of invasive carcinomas, and 4,909 (16.5%) were of carcinoma in situ. The median age of women with breast cancer was 52.8 years, and breast cancer was most commonly diagnosed in the age group of 40-49 years. The number of patients who have undergone breast conserving surgery has continued to increase since 2016, with 68.6% of patients undergoing breast conserving surgery in 2019. The incidence of early-stage breast cancer continues to increase, with stage 0 or I breast cancer accounting for 61.6% of cases. The most common subtype of breast cancer is the hormone receptor-positive human epidermal growth factor receptor 2-negative subtype (63.1%). The 5-year relative survival rate of patients with breast cancer from 2015 to 2019 was 93.6%, with an increase of 14.3% compared to that from 1993 to 1995. This report improves our understanding of breast cancer characteristics in South Korea.

APOBEC Mutational Signatures in Hormone Receptor-Positive Human Epidermal Growth Factor Receptor 2-Negative Breast Cancers Are Associated With Poor Outcomes on CDK4/6 Inhibitors and Endocrine Therapy.

APOBEC mutagenesis underlies somatic evolution and accounts for tumor heterogeneity in several cancers, including breast cancer (BC). In this study, we evaluated the characteristics of a real-world cohort for time-to-treatment discontinuation (TTD) and overall survival on CDK4/6 inhibitors (CDK4/6i) plus endocrine therapy (ET) and immune checkpoint inhibitors. Comprehensive genomic profiling results from 29,833 BC samples were analyzed for tumor mutational burden and APOBEC signatures. For clinical outcomes, a deidentified nationwide (United States-based) BC Clinico-Genomic Database (CGDB) was evaluated with log-rank and Cox models. Patients with hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) BC who received first-line ET and CDK4/6i were included. Eligible patients from Mayo Clinic and Duke University were HR+ HER2- BC with sequencing data between September 2013 and July 2020. Of 29,833 samples sequenced, 7.9% were APOBEC+ with a high rate in invasive lobular carcinoma (16.7%) and in metastatic tumors (9.7%) relative to locally biopsied BC (4.3%; P < .001). In CGDB, 857 patients with HR+ HER2- BC received ET plus CDK4/6i in the first line. APOBEC+ patients had significantly shorter TTD on ET plus CDK4/6i than APOBEC- patients, 7.8 (95% CI, 4.3 to 14.6) versus 12.4 months (95% CI, 11.2 to 14.1; hazard ratio, 1.6; 95% CI, 1.03 to 2.39; P = .0036). Clinical benefit to immune checkpoint inhibitors was observed in HR+ HER2-, APOBEC+, tumor mutational burden-high patients, with four of nine CGDB patients (TTD 0.3-11.3 months) and four of six patients in Duke/Mayo cohorts (TTD 0.9-40.5 months) with a TTD of ≥ 3 months. APOBEC+ HR+ HER2- patients had shorter TTD on first-line ET plus CDK4/6i relative to APOBEC- patients. Further research is needed to optimize the treatment of APOBEC+ HR+ HER2- BC and to investigate the efficacy of immunotherapeutic strategies in this population.

The effect of non-oncology drugs on clinical and genomic risk in early luminal breast cancer

An effect of non-oncology medications on cancer outcome has been proposed. In this study, we aimed to systematically examine the impact of commonly prescribed non-oncology drugs on clinical risk and on the genomic risk [based on the Oncotype DX recurrence score (RS)] in early breast cancer (BC). We collected data on clinical risk (stage and grade), genomic risk (Oncotype DX RS), and on non-oncology medications administered to 1423 patients with estrogen receptor-positive human epidermal growth factor receptor 2-negative BC during the month of their surgery. The influence of various medications on clinical and genomic risks was evaluated by statistical analysis. Out of the multiple drugs we examined, levothyroxine was significantly associated with a high Oncotype DX RS (mean 24.78; P < 0.0001) and metformin with a low Oncotype DX RS (mean 14.87; P < 0.01) compared with patients not receiving other non-oncology drugs (mean 18.7). By contrast, there were no differences in the clinical risk between patients receiving metformin, levothyroxine, or no other non-oncology drugs. Notably, there was no association between the consumption of levothyroxine and metformin and proliferation marker (Ki67) levels, but both drugs were significantly associated with progesterone-related features, suggesting that they influence genomic risk through estrogen-dependent signaling. The results of this study indicate a significant impact of metformin and levothyroxine on clinical decisions in luminal BC, with potential impact on the clinical course of these patients.

Absolute Lymphocyte Count Is an Independent Prognostic Factor for ER-positive HER2-negative Advanced Breast Cancer Patients Treated With CDK4/6 Inhibitors.

The aim of this study was to elucidate the clinical significance of peripheral blood biomarkers, including absolute lymphocyte count (ALC), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and C-reactive protein (CRP) in patients with estrogen receptor-positive human epidermal growth factor receptor 2-negative advanced breast cancer treated with the CDK4/6 inhibitors, abemaciclib and palbociclib. A total of 83 patients treated with fulvestrant plus abemaciclib or palbociclib were included in this study. Progression-free survival (PFS) and overall survival (OS) were compared in relation to baseline levels of ALC, NLR, PLR and CRP. The cut-off values of ALC, NLR, PLR, and CRP for PFS were determined from the receiver operating characteristic curve using the Youden index for area under the curve and set at 1,212/μl, 1.964, 170 and 0.220 mg/dl, respectively. In the abemaciclib-treated group, ALC-high patients showed significantly better PFS than ALC-low patients (p=0.0151) and multivariate analysis revealed that ALC was an independent prognostic factor for PFS (p=0.0085). In the palbociclib-treated group, there was no significant relationship between any peripheral blood biomarkers and PFS. In both treatment groups, ALC-high patients showed significantly better OS than ALC-low patients (p=0.0169 and 0.0290, respectively). Multivariate analysis revealed ALC was an independent prognostic factor for OS in both abemaciclib- and palbociclib-treated groups (p=0.0112 and 0.0202, respectively). ALC is an independent prognostic factor for estrogen receptor-positive human epidermal growth factor receptor 2-negative advanced breast cancer patients treated with the CDK4/6 inhibitors abemaciclib and palbociclib.

Factors associated with overall survival after recurrence in patients with ER-positive/HER2-negative postmenopausal breast cancer: an ad hoc analysis of the JBCRG-C06 Safari study.

The Safari study (UMIN000015168) was a retrospective, multicenter study in which 1072 consecutive cases of estrogen receptor-positive advanced breast cancer treated using 500mg fulvestrant were registered. We previously reported the relationship between the patient factors and overall survival after the diagnosis using the same cases and the same factors for the analysis of time to treatment failure in patients with estrogen receptor-positive advanced breast cancer. The current study is an ad hoc analysis that focused on the relationship between the patient factors and overall survival after recurrence by adding factors generally associated with overall survival after recurrence. The overall survival after recurrence in patients with estrogen receptor-positive human epidermal growth factor receptor 2 negative recurrent breast cancer was analyzed via univariate and multivariate analyses with a Cox proportional hazards model. A total of 598 cases were used for the analysis of overall survival after recurrence. Multivariate analysis revealed that favorable overall survival (median, 6.4years) was significantly correlated with long time from recurrence to fulvestrant use (≥3years), low nuclear or histological grade (G3 vs. G1), long time to treatment failure of initial palliative endocrine therapy (≥12months) and long time to initial palliative chemotherapy (≥2years). The results of this study indicate that sequential endocrine monotherapy may be a useful treatment option for patients with estrogen receptor-positive/human epidermal growth factor receptor 2 negative recurrent breast cancer who have been successfully treated with initial long-term palliative endocrine therapy.

Association of Adjuvant Hormone Therapy Timing With Overall Survival Among Patients With Hormone Receptor–Positive Human Epidermal Growth Factor Receptor-2–Negative Early Breast Cancer Without Chemotherapy

Studies have shown that delayed initiation of surgery and adjuvant chemotherapy is associated with lower rates of breast cancer survival. However, it remains unclear whether delayed initiation of adjuvant hormone therapy (AHT) is associated with survival. To assess the association of time to adjuvant hormone therapy (TTH) with breast cancer survival and evaluate the factors associated with AHT. This cohort study examined data from the National Cancer Database from 2004 through 2014 to assess the association of TTH (stratified as ≤150 and >150 days) with cancer survival. All patients included were diagnosed with stage I to stage III hormone receptor-positive, human epidermal growth factor receptor-2 (ERBB2; formerly HER2)-negative invasive breast cancer and underwent AHT without chemotherapy. Data were analyzed from April 2019 to May 2020. AHT was administered at different time points following surgical procedures for breast cancer treatment. An inverse probability of treatment weighting (IPTW) model was constructed to evaluate overall survival by adjusting for treatment facility, patient demographics, tumor characteristics, and treatment; multivariable logistic regression was conducted to assess factors associated with delayed treatment. A total of 144 103 patients (median [IQR] follow-up, 36.6 months [25.5-49.2 months]; mean [SD] age, 63.7 [11.6] years) were identified, which included 142 916 (99.2%) women, 11 574 (8.0%) Black patients, and 126 013 (87.4%) White patients. Of these, 134 873 patients (93.6%) had a TTH of 150 days or less and 9230 patients (6.4%) had a TTH longer than 150 days. The IPTW-based Cox model demonstrated that patients with delayed AHT (ie, a TTH past 150 days) were associated with decreased survival (hazard ratio [HR], 1.31; 95% CI, 1.26-1.35; P < .001) compared with those receiving the timely treatment (TTH ≤150 days). Several sensitivity analyses (including IPTW with stabilized weight [HR, 1.31; 95% CI, 1.19-1.45; P < .001], propensity score matching [HR, 1.41; 1.13-1.76; P = .002], and propensity score regression adjustment [HR, 1.29; 95% CI, 1.16-1.43; P < .001]) and exploratory subgroup analyses yielded similar trends. Factors associated with delayed AHT included Black racial identity (OR, 1.66; 95% CI, 1.55-1.77), nonprivate insurance (eg, no insurance: OR, 1.46; 95% CI, 1.26-1.70), living in large metropolitan or metropolitan areas (reference vs urban, less urban, or rural: OR, 0.82; 95% CI, 0.76-0.87), treatment in a community hospital (reference vs academic or research: OR, 0.91; 95% CI, 0.84-0.98), Charlson-Deyo Comorbidity Index score 2 or higher (OR, 1.17; 95% CI, 1.04-1.32), poor grade differentiation (OR, 1.42; 95% CI, 1.32-1.53), II and III pathological stage (stage III: OR, 3.13; 95% CI, 2.76-3.54), estrogen receptor-positive (ER+)/progesterone receptor-negative (PR-) or ER-/PR+ (OR, 1.22; 95% CI, 1.13-1.31), receiving breast conservation surgery (reference vs mastectomy: OR, 0.87; 95% CI, 0.79-0.94), and radiotherapy (reference vs no radiotherapy: OR, 0.56; 95% CI, 0.52-0.61). The delay of the initiation of AHT past 150 days was associated with diminished survival in hormone receptor-positive, ERBB2-negative patients with breast cancer who did not receive chemotherapy. Efforts should be made to address factors associated with delayed treatment to improve survival.

Trilaciclib: A First-in-class Therapy to Reduce Chemotherapy-induced Myelosuppression

Oral cyclin-dependent kinase (CDK) 4/6 inhibitors are routinely used to treat metastatic hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer in combination with endocrine therapy; however, they have not been widely used for other tumour types. Trilaciclib is an intravenous CDK 4/6 inhibitor that causes reversible cell cycle arrest in the G1 phase and transient haematopoietic stem and progenitor cell arrest. Ultimately, this protects the bone marrow and immune system from the cytotoxic impact of chemotherapy. Trilaciclib has been evaluated in extensive-stage small cell lung cancer in combination with chemotherapy as a myeloprotective agent and was approved by the US Food and Drug Administration for this use in February 2021. In metastatic triple-negative breast cancer, trilaciclib plus chemotherapy had a survival benefit over chemotherapy alone. This is being further investigated in a phase III trial. This review outlines the mechanism of this novel agent and describes preclinical and clinical data, characterizing its use in extensive-stage small cell lung cancer and advanced triple-negative breast cancer.

Overcoming resistance to endocrine therapy in hormone receptor-positive human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer: a meta-analysis and systemic review of randomized clinical trials.

New targeted therapies have been developed to overcome resistance to endocrine therapy (ET) and improve the outcome of HR+/HER2- advanced breast cancer (ABC). We conducted a meta-analysis and systemic review on randomized controlled trials evaluating various targeted therapies in combination with ET in HR+/HER2- ABC. PUBMED and EMBASE databases were searched for eligible trials. Hazard ratios (HRs) for progression-free survival (PFS), odds ratios (ORs) for objective response rate (ORR), clinical benefit rate (CBR), and toxicity were meta-analyzed. Twenty-six studies with data on 10 347 patients were included and pooled. The addition of cyclin-dependent kinase 4/6 inhibitors to ET significantly improved median PFS (pooled HR = 0.547, P < 0.001), overall survival (pooled HR= 0.755, P < 0.001), and tumor response rates (ORR, pooled OR= 1.478, P < 0.001; CBR, pooled OR= 1.201, P < 0.001) with manageable toxicities (pooled OR= 3.280, P < 0.001). The mammalian targets of rapamycin inhibitors and exemestane were not clinically beneficial for this pooled population including ET-naïve and ET-resistant patients. Moderate improvement in PFS (pooled HR = 0.686, P < 0.001) yet pronounced toxicities (pooled OR = 2.154, P < 0.001) were noted in the combination of phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitors with fulvestrant. Future studies are warranted to optimize the population and the dosing sequence of these available options.

Ribociclib plus fulvestrant for advanced breast cancer: Health-related quality-of-life analyses from the MONALEESA-3 study

PurposeIn the MONALEESA-3 Phase III trial of patients with hormone receptor–positive human epidermal growth factor receptor–negative advanced breast cancer, ribociclib plus fulvestrant significantly improved progression-free survival (PFS) and overall survival (OS). Here, we present patient-reported outcomes from the trial, including health-related quality of life (HRQOL). MethodsPatients were randomized (2:1) to receive ribociclib plus fulvestrant or placebo plus fulvestrant. Time to definitive 10% deterioration (TTD) from baseline in HRQOL (global health status [GHS] from the EORTC QLQ-C30 questionnaire) and pain (BPI-SF questionnaire) were assessed using Kaplan-Meier estimates; a stratified Cox regression model was used to estimate the hazard ratio (HR) and 95% CIs. ResultsDeterioration ≥10% in the EORTC-QLQ-C30 GHS was observed in 33% of patients in the ribociclib group vs 34% of patients in the placebo (reference) group (HR for TTD ≥ 10% = 0.81 [95% CI, 0.62–1.1]). Similar findings were noted for TTD ≥5% (HR = 0.79 [95% CI, 0.61–1.0]) and TTD ≥15% (HR = 0.81 [95% CI, 0.60–1.08]). TTD ≥10% in emotional functioning (HR = 0.76 [95% CI, 0.57–1.01]) trended in favor of the ribociclib group, whereas results for fatigue and pain were similar between arms. TTD ≥10% in BPI-SF pain severity index score (HR = 0.77 [95% CI, 0.57–1.05]) and worst pain item score (HR = 0.81 [95% CI, 0.58–1.12]) trended in favor of ribociclib vs placebo. ConclusionsIn addition to significantly prolonging PFS and OS compared with placebo plus fulvestrant, adding ribociclib to fulvestrant maintains HRQOL.

Plasma-Based Longitudinal Evaluation of ESR1 Epigenetic Status in Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer.

BackgroundEndocrine therapy (ET) is the mainstay of treatment for hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer; however, adaptive mechanisms emerge in about 25–30% of cases through alterations in the estrogen receptor ligand-binding domain, with a consequent ligand-independent estrogen receptor activity. Epigenetic-mediated events are less known and potentially involved in alternative mechanisms of resistance. The aim of this study was to test the feasibility of estrogen receptor 1 (ESR1) epigenetic characterization through liquid biopsy and to show its potential longitudinal application for an early ET sensitivity assessment.MethodsA cohort of 49 women with hormone receptor-positive HER2-negative MBC was prospectively enrolled and characterized through circulating tumor DNA using methylation-specific droplet digital PCR (MS-ddPCR) before treatment start (BL) and after 3 months concomitantly with computed tomography (CT) scan restaging (EV1). ESR1 epigenetic status was defined by assessing the methylation of its main promoters (promA and promB). The most established cell-free tumor DNA (ctDNA) factors associated with ET resistance [ESR1 and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations] were assessed through next-generation sequencing. Associations were tested through Mann–Whitney U test, matched pairs variations through Wilcoxon signed rank test, and survival was analyzed by log-rank test.ResultsThe ET backbone was mainly based on aromatase inhibitors (AIs) (70.83%) in association with CDK4/6 inhibitors (93.75%). Significantly lower promA levels at baseline were observed in patients with liver metastases (P = 0.0212) and in patients with ESR1 mutations (P = 0.0091). No significant impact on PFS was observed for promA (P = 0.3777) and promB (P = 0.7455) dichotomized at the median while a ≥2-fold increase in promB or in either promA or promB at EV1 resulted in a significantly worse prognosis (respectively P = 0.0189, P = 0.0294). A significant increase at EV1 was observed for promB among patients with PIK3CA mutation (P = 0.0173). A trend was observed for promB in ESR1 wild-type patients and for promA in the ESR1 mutant subgroup.ConclusionThe study proofed the concept of an epigenetic characterization strategy based on ctDNA and is capable of being integrated in the current clinical workflow to give useful insights on treatment sensitivity.

Artificial Intelligence Treatment Decision Support For Complex Breast Cancer Among Oncologists With Varying Expertise.

The aim of the current study was to assess treatment concordance and adherence to National Comprehensive Cancer Network breast cancer treatment guidelines between oncologists and an artificial intelligence advisory tool. Study cases of patients (N = 1,977) who were at high risk for recurrence or who had metastatic disease and cell types for which the advisory tool was trained were obtained from the Chinese Society for Clinical Oncology cancer database (2012 to 2017). A cross-sectional observational study was performed to examine treatment concordance and guideline adherence among an artificial intelligence advisory tool and 10 oncologists with varying expertise-three fellows, four attending physicians, and three chief physicians. In a blinded fashion, each oncologist provided treatment advice on an average of 198 cases and the advisory tool on all cases (N = 1,977). Results are reported as rates and logistic regression odds ratios. Concordance for the recommended treatment was 0.56 for all physicians and higher for fellows compared with chief and attending physicians (0.68 v 0.54; 0.49; P = .001). Concordance differed by hormone receptor subtype-TNM stage, with the lowest for hormone receptor-positive human epidermal growth factor receptor 2/neu-positive cancers (0.48) and highest for triple-negative breast cancers (0.71) across most TNM stages. Adherence to National Comprehensive Cancer Network guidelines was higher for oncologists compared with the advisory tool (0.96 v 0.82; P < .003) and lower for fellows compared with attending physicians (0.93 v 0.98; 0.96; P = .04). Study findings reflect a complex breast cancer case mix, the limits of medical knowledge regarding optimum treatment, clinician practice patterns, and use of a tool that reflects expertise from one cancer center. Additional research in different practice settings is needed to understand the tool's scalability and its impact on treatment decisions and clinical and health services outcomes.

Abstract P5-04-29: Efficacy and safety of low-dose everolimus in Chinese HR-positive, HER2-negative metastatic breast cancer patients

Abstract Background: Everolimus has been testified to be effective among postmenopausal women with hormone receptor-positive human epidermal growth factor receptor-2 negative (HR+/HER2-) metastatic breast cancer (MBC). However, everolimus at dose of 10mg was accompanied by a higher incidence of mTOR-inhibitor class-effect adverse events (AEs) which usually leading to dose reduction or interruption. Additionally, some studies suggested that there was no correlation between dose intensity (5 vs. 10 mg labeled dose) and efficacy. Consequently, we conducted the present study aiming to explore the efficacy and safety of everolimus at dose of 5 mg plus endocrine therapy in Chinese population. Methods: 68 HR+/HER2- MBC patients were included in this exploratory study who received everolimus at the dose of 5mg in Zhejiang Cancer Hospital between September 2014 and September 2017. Progression free survival(PFS) and overall survival(OS) were estimated by the Kaplan- Meier method, and the hazard ratios(HRs) and corresponding 95% confidence intervals(CIs) were estimated using the Cox proportional harzard model. Besides, objective response rate(ORR), clinical benefitrate(CBR) and safety profile were also evaluated. Results: After a median follow up of 14 months, PFS was 5.3 months (95%CI 4.2-6.4), and OS was immature. 16(23.5%) were at the first or second-line, 52(76.5%) were at third-line or later. PFS for the first and second-line is significantly longer than that for the third-line or later (12.9 months vs. 4.6 months, P=0.009, HR=0.395, 95% CI=0.192-0.811). 11(16.2%) achieved partial response (PR), 42(61.7%) had stable disease (SD), and 15(22.1%) reported progressive disease (PD). The ORR and CBR were 16.2%, 35.2%, respectively. Most common all grade adverse events were stomatitis(26.5%), fatigue(10.0%), infection(11.8%), thrombocytopenia(5.9%), anemia(4.4%), hyperglycemia(4.4%). The most common ≥3 grade adverse events were stomatitis(4.4 %), infection(2.2%) and thrombocytopenia(1.1%). Conclusions: The combination of low-dose everolimus and endocrine therapy was highly effective especially at the earlier line in Chinese population. And the safety profiles were similar to previous studies but the incidences were greatly lower. The combination of low-dose everolimus and endocrine therapy may become a proper option for HR+/HER2- MBC. Citation Format: Shao X, Wang X, Chen Z, Zheng Y. Efficacy and safety of low-dose everolimus in Chinese HR-positive, HER2-negative metastatic breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-29.

Significance of intrinsic breast cancer subtypes on the long-term prognosis after neoadjuvant chemotherapy

BackgroundThe prognosis of breast cancer and the treatment response to neoadjuvant chemotherapy (NAC) differ depending on the intrinsic molecular subtypes. We evaluated the prognostic significance of immunohistological subtypes in patients with recurrent breast cancer after treatment with NAC and surgery.MethodsA total of 237 patients with breast cancer treated with NAC and subsequent curative surgery between 2007 and 2015 were analyzed. The correlation between intrinsic molecular subtypes and clinicopathological features, prognosis, and pathological complete response (pCR) rate of NAC were investigated retrospectively.ResultsThere were 55 (23.2%) patients with recurrence after surgery. No significant difference in post-recurrence survival (PRS) was noted among the subtypes (p = 0.397). In patients with estrogen receptor-positive human epidermal growth factor receptor (HER) 2-negative (luminal) malignancy, PRS was significantly better in the pCR group than in the non-pCR group (p = 0.031). Conversely, pCR was not a significant predictor of improved PRS in patients with triple-negative breast cancer (TNBC; p = 0.329). Multivariate analysis revealed that the efficacy of NAC [hazard ratio (HR) 300.204, p < 0.001] and the initial metastasis site (HR 15.037, p = 0.005) were independent predictors for PRS in patients with luminal breast cancer, while Ki-67 (HR 51.171, p = 0.020) and the initial metastasis site (HR 13.318, p = 0.048) were independent predictors for PRS in patients with TNBC.ConclusionsThe prognostic factors for each intrinsic subtype should be evaluated separately in patients with recurrent breast cancer following NAC and surgery.