Outcomes of older adults with early-stage triple-negative breast cancer (TNBC) receiving chemotherapy: a single-institution experience.

BACKGROUND: Despite lower chemotherapy use in older triple-negative breast cancer (TNBC) patients, their outcomes match younger counterparts. We compared outcomes in early-stage TNBC patients by age receiving chemotherapy at a major cancer center with a national TNBC database. METHODS: Retrospective study using institutional data on stage I-III TNBC (ER/PR < 10%) women with neoadjuvant/adjuvant chemotherapy. Based on their ages at diagnosis, patients were stratified into four categories: ≤40, 41-59, 60-69, and ≥ 70 years. Demographic and clinical characteristics recorded included race, disease stage, ER/PR positivity, treatment regimen, lymphatic or vascular invasion (LVI), histologic grade, Ki-67 level, body mass index (BMI), and pathologic complete response (pCR) following neoadjuvant treatment and are summarized using descriptive statistics. The primary endpoints were overall survival (OS), disease-free survival (DFS), and distant disease-free survival (DDFS); all were estimated using the Kaplan-Meier method. Both univariate and multivariate (MV) Cox regressions were applied to evaluate the impact of important covariates on these time-to-event endpoints. RESULTS: Of the 2336 patients studied, 492 (21.1%) were ≤ 40 years old, 1239 (53.1%) were 41-59, 461 (19.7%) were 60-69, and 144 (6.2%) were ≥ 70. In the univariate regression model of OS/DFS/DDFS, age ≥ 70 was significantly associated with worse OS (p = 0.0217); other factors associated with worse OS were non-anthracycline-based chemotherapy, higher tumor stage, and neoadjuvant chemotherapy. The multivariate Cox regression model, adjusted for race and stage, showed no significant effects of age on OS; however, patients ≥ 70 years old who received non-anthracycline treatment combinations had worse DFS (hazard ratio = 0.349 vs. 1.049, p = 0.0293) and DDFS (hazard ratio = 0.317 vs. 1.016, p = 0.0251) than patients ≤ 40 years old. DFS from MV model after adjusting for age, race, and disease stage, the hazard ratio between anthracycline + taxane treatments and anthracycline + other treatments in patients ≥ 70 years old was statistically significantly lower than in patients ≤ 40 years old (hazard ratios [HRs] = 0.349 vs. 1.049, p = 0.0293). CONCLUSIONS: Our findings indicate that outcomes such as DFS are less favorable in older compared to younger patients with early-stage TNBC, primarily in those who did not receive an anthracycline based chemotherapy regimen.

Measures of functional status in older patients treated with palbociclib for advanced breast cancer.

INTRODUCTION: Limited data are available on the effects of treatment for advanced breast cancer (ABC) in older patients because this population has limited enrollment in clinical trials. Data generated from the prospective, noninterventional POLARIS study of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative ABC may help bridge the gap in our understanding of the tolerability and outcomes in this vulnerable population. MATERIALS AND METHODS: We evaluated measures of geriatric impairments and activities of daily living in patients with ABC aged ≥70 years in POLARIS to evaluate the change within six months of palbociclib initiation. Geriatric impairments and activities of daily living (functional) status were assessed using the Geriatric 8 (G8) and Activities of Daily Living (ADL) screening tools. The G8, ADL, and Eastern Cooperative Oncology Group performance status (ECOG PS) scores were assessed at baseline and month six through end of treatment with palbociclib. ECOG PS scores were also stratified by G8 and ADL score severity subgroups (G8: ≤14 = impaired subgroup; >14 = not at all impaired subgroup; ADL: <18 = dependent subgroup, 18 = independent subgroup). RESULTS: At data cutoff in November 2020, of 1282 POLARIS patients of all ages, 287 (22.4%) were ≥ 70 years old and completed ≥6 months of palbociclib therapy. At baseline, 117 (45%; n = 260) of these patients had an ECOG PS score of 0, 143 (55%; n = 260) had ECOG PS score > 0, 248 (86%) had G8 scores (mean [SD] 13.6 [2.14]), and 256 (89%) had ADL scores (17.7 [1.03]) among the available 287 patients. At six months, 102 (40%; n = 255) had an ECOG PS score of 0, 153 (60%; n = 255) had ECOG PS score > 0, 198 (69%) had G8 scores (13.6 [1.99]), and 211 (74%) had ADL scores (17.6 [1.22]) among the 287 available patients. There was no mean change (standard deviation) from baseline to 6 months in mean ECOG PS scores (0.0 [0.61], P = 0.24), G8 scores (0.0 [2.17], P = 0.89), or ADL scores (0.0 [1.00], P = 0.62). DISCUSSION: In this subgroup analysis of older patients with ABC from POLARIS, functional status and impairment outcomes were preserved in older patients receiving palbociclib. G8, ADL, and ECOG PS scores were generally maintained during the first six months of palbociclib therapy. CLINICALTRIALS: govidentification number. NCT03280303.

Outcomes of male patients with HR+/HER2- advanced breast cancer receiving palbociclib in the real-world POLARIS study.

PURPOSE: Data on treatments for male breast cancer patients are limited owing to rarity and underrepresentation in clinical trials. The real-world POLARIS study gathers data on palbociclib use for the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) in female and male patients. This sub-analysis describes real-world palbociclib treatment patterns, clinical outcomes, and quality of life (QoL) in male patients. METHODS: POLARIS is a prospective, noninterventional, multicenter, real-world study of patients with HR+/HER2- ABC receiving palbociclib. Assessments included medical record reviews, patient QoL questionnaires (European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire-Core 30), site characteristics questionnaires, and physician treatment selection surveys. Variables included demographics, disease history, global health status/QoL, clinical assessments and adverse events. Analyses were descriptive in nature. For clinical outcomes, real-world tumor responses and progression were determined by physician assessment in routine clinical practice. Real-world progression-free survival (rwPFS) was described using the Kaplan-Meier method. RESULTS: At data cutoff, 15 male patients were enrolled (median age, 66 years). Nine patients received palbociclib as a first-line treatment and 6 as a second-line or later treatment. Patients received a median of 20 cycles of palbociclib. Neutropenia was experienced by 2 patients and grade ≥ 3 adverse events were reported in 11 patients. Global health status/QoL scores remained generally consistent during the study. One patient (6.7%) achieved a complete tumor response, 4 (26.7%) a partial response, and 8 (53.3%) stable disease. Median rwPFS was 19.8 months (95% CI, 7.4-38.0). Median follow-up duration was 24.7 months (95% CI, 20.0-35.7). CONCLUSION: This real-world analysis showed that palbociclib was well tolerated and provides preliminary data on treatment patterns and outcomes with palbociclib in male patients with HR+/HER2- ABC, helping inform the use of palbociclib in this patient subgroup. TRIAL IDENTIFIER: NCT03280303.

Real-World Analysis of Clinical and Demographic Characteristics, Treatment Patterns, and Outcomes in Predominantly Older Patients with HR+/HER2- Metastatic Breast Cancer Receiving Abemaciclib in Routine Clinical Practice.

INTRODUCTION: Hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) is the most frequently diagnosed metastatic breast cancer (mBC) subtype. Combinations of endocrine therapy (ET) with cyclin-dependent kinase 4/6 inhibitors (CDK4 & 6is) improve outcomes compared with ET alone. The efficacy and safety of abemaciclib among patients with HR+/HER2- mBC has been demonstrated in the MONARCH clinical trials; however, there is a paucity of real-world evidence, particularly in older patients. METHODS AND MATERIALS: This retrospective cohort study analyzed the electronic medical record data/charts of adult patients with HR+/HER2- mBC receiving abemaciclib in US-based community oncology settings (1 September 2017 to 30 September 2019). Patients with other primary malignancies, clinical trial enrollment, and incomplete charts were excluded. Patient characteristics, treatment attributes and patterns, and real-world outcomes (clinical benefit rate [CBR] and stable disease among patients with response data available, time to chemotherapy [TTC], time to treatment discontinuation [TTD], and progression-free survival [PFS]) were summarized. Multivariable models evaluated the association between demographic/clinical characteristics and outcomes. RESULTS: Of the 448 final patients, 99% were female, with a median age of 67 years (25% were ≥ 75 years) and median follow-up of 11 months; most (60%) initiated abemaciclib within 2 years of mBC diagnosis. Patients received a median of 1 (P25 = 0, P75 = 3) prior line of therapy for mBC before abemaciclib, including other CDK4 & 6is (48%) and prior chemotherapy (31%); most (57%) had visceral disease. The CBR for the overall population was 53%, with 48% achieving stable disease. The median TTC was not reached; median TTD was 249 days (95% confidence interval [CI]: 202, 304). The median PFS was 329 days (95% CI 266, 386). The discontinuation rate of abemaciclib owing to adverse events (30%) trended higher with age (years) (P = 0.027): 18-49 (n = 42; 19%), 50-64 (n = 155; 25%), 65-74 (n = 138; 32%), 75-84 (n = 82; 37%), ≥ 85 (n = 31; 49%); only 23% of patients overall had a dose hold or reduction prior to discontinuation. CONCLUSIONS: These patients were older than those in the MONARCH studies with substantial visceral disease, and prior chemotherapy and CDK4 & 6i use. Discontinuation rates were higher than in previous real-world studies (11.9%), highlighting the need for proactive management to optimize outcomes, particularly in older patients with mBC.

A phase II study of neoadjuvant atezolizumab and nab-paclitaxel in patients with anthracycline-resistant early-stage triple-negative breast cancer.

PURPOSE: Neoadjuvant anti-PD-(L)1 therapy improves the pathological complete response (pCR) rate in unselected triple-negative breast cancer (TNBC). Given the potential for long-term morbidity from immune-related adverse events (irAEs), optimizing the risk-benefit ratio for these agents in the curative neoadjuvant setting is important. Suboptimal clinical response to initial neoadjuvant therapy (NAT) is associated with low rates of pCR (2-5%) and may define a patient selection strategy for neoadjuvant immune checkpoint blockade. We conducted a single-arm phase II study of atezolizumab and nab-paclitaxel as the second phase of NAT in patients with doxorubicin and cyclophosphamide (AC)-resistant TNBC (NCT02530489). METHODS: Patients with stage I-III, AC-resistant TNBC, defined as disease progression or a < 80% reduction in tumor volume after 4 cycles of AC, were eligible. Patients received atezolizumab (1200 mg IV, Q3weeks × 4) and nab-paclitaxel (100 mg/m2 IV,Q1 week × 12) as the second phase of NAT before undergoing surgery followed by adjuvant atezolizumab (1200 mg IV, Q3 weeks, × 4). A two-stage Gehan-type design was employed to detect an improvement in pCR/residual cancer burden class I (RCB-I) rate from 5 to 20%. RESULTS: From 2/15/2016 through 1/29/2021, 37 patients with AC-resistant TNBC were enrolled. The pCR/RCB-I rate was 46%. No new safety signals were observed. Seven patients (19%) discontinued atezolizumab due to irAEs. CONCLUSION: This study met its primary endpoint, demonstrating a promising signal of activity in this high-risk population (pCR/RCB-I = 46% vs 5% in historical controls), suggesting that a response-adapted approach to the utilization of neoadjuvant immunotherapy should be considered for further evaluation in a randomized clinical trial.

Characteristics and Outcomes in Cases of US Male Patients with Metastatic Breast Cancer Receiving Abemaciclib in Routine Clinical Practice.

INTRODUCTION: Breast cancer in males constitutes approximately 1% of all breast cancer cases globally. Despite extensive treatment experience with abemaciclib in women with metastatic breast cancer (MBC), real-world evidence in male MBC is lacking. METHODS: This analysis was a part of a broader, retrospective study that analyzed electronic medical records and charts of 448 men and women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) MBC who initiated an abemaciclib-containing regimen from January 2017 through September 2019. Data were collected from the Florida Cancer Specialists & Research Institute and the Electronic Medical Office Logistics Health Oncology Warehouse Language™ databases and summarized descriptively. Real-world best response was described: complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). RESULTS: Data for six male patients with MBC who were treated with abemaciclib in combination with an aromatase inhibitor (AI) or fulvestrant are presented. Four patients were aged ≥ 75 years, and four patients had ≥ 3 metastatic sites, including visceral involvement. Abemaciclib was initiated in/after third-line (≥ 3L) in four patients, and patients had history of treatment with AI (n = 4), chemotherapy (n = 3), and/or prior cyclin-dependent kinase 4 and 6 inhibitors (n = 2) in the metastatic setting. Abemaciclib + fulvestrant was the most common abemaciclib-containing regimen (n = 4). Best response was documented in four patients: 1 each with CR, PR, SD, and PD. CONCLUSION: Prevalence of male MBC in this dataset was consistent with expected prevalence in the broader population. Most male patients received an abemaciclib-containing regimen in ≥ 3L, with anti-cancer activity observed despite heavy metastatic burden and prior treatments in a metastatic setting.

Evaluation of Alisertib Alone or Combined With Fulvestrant in Patients With Endocrine-Resistant Advanced Breast Cancer: The Phase 2 TBCRC041 Randomized Clinical Trial.

Importance: Aurora A kinase (AURKA) activation, related in part to AURKA amplification and variants, is associated with downregulation of estrogen receptor (ER) α expression, endocrine resistance, and implicated in cyclin-dependent kinase 4/6 inhibitor (CDK 4/6i) resistance. Alisertib, a selective AURKA inhibitor, upregulates ERα and restores endocrine sensitivity in preclinical metastatic breast cancer (MBC) models. The safety and preliminary efficacy of alisertib was demonstrated in early-phase trials; however, its activity in CDK 4/6i-resistant MBC is unknown. Objective: To assess the effect of adding fulvestrant to alisertib on objective tumor response rates (ORRs) in endocrine-resistant MBC. Design, Setting, and Participants: This phase 2 randomized clinical trial was conducted through the Translational Breast Cancer Research Consortium, which enrolled participants from July 2017 to November 2019. Postmenopausal women with endocrine-resistant, ERBB2 (formerly HER2)-negative MBC who were previously treated with fulvestrant were eligible. Stratification factors included prior treatment with CDK 4/6i, baseline metastatic tumor ERα level measurement (<10%, ≥10%), and primary or secondary endocrine resistance. Among 114 preregistered patients, 96 (84.2%) registered and 91 (79.8%) were evaluable for the primary end point. Data analysis began after January 10, 2022. Interventions: Alisertib, 50 mg, oral, daily on days 1 to 3, 8 to 10, and 15 to 17 of a 28-day cycle (arm 1) or alisertib same dose/schedule with standard-dose fulvestrant (arm 2). Main Outcomes and Measures: Improvement in ORR in arm 2 of at least 20% greater than arm 1 when the expected ORR for arm 1 was 20%. Results: All 91 evaluable patients (mean [SD] age, 58.5 [11.3] years; 1 American Indian/Alaskan Native [1.1%], 2 Asian [2.2%], 6 Black/African American [6.6%], 5 Hispanic [5.5%], and 79 [86.8%] White individuals; arm 1, 46 [50.5%]; arm 2, 45 [49.5%]) had received prior treatment with CDK 4/6i. The ORR was 19.6%; (90% CI, 10.6%-31.7%) for arm 1 and 20.0% (90% CI, 10.9%-32.3%) for arm 2. In arm 1, the 24-week clinical benefit rate and median progression-free survival time were 41.3% (90% CI, 29.0%-54.5%) and 5.6 months (95% CI, 3.9-10.0), respectively, and in arm 2 they were 28.9% (90% CI, 18.0%-42.0%) and 5.4 months (95% CI, 3.9-7.8), respectively. The most common grade 3 or higher adverse events attributed to alisertib were neutropenia (41.8%) and anemia (13.2%). Reasons for discontinuing treatment were disease progression (arm 1, 38 [82.6%]; arm 2, 31 [68.9%]) and toxic effects or refusal (arm 1, 5 [10.9%]; arm 2, 12 [26.7%]). Conclusions and Relevance: This randomized clinical trial found that adding fulvestrant to treatment with alisertib did not increase ORR or PFS; however, promising clinical activity was observed with alisertib monotherapy among patients with endocrine-resistant and CDK 4/6i-resistant MBC. The overall safety profile was tolerable. Trial Registration: ClinicalTrials.gov Identifier: NCT02860000.

A biomarker of aging, p16, predicts peripheral neuropathy in women receiving adjuvant taxanes for breast cancer.

Identifying patients at higher risk of chemotherapy-induced peripheral neuropathy (CIPN) is a major unmet need given its high incidence, persistence, and detrimental effect on quality of life. We determined if the expression of p16, a biomarker of aging and cellular senescence, predicts CIPN in a prospective, multi-center study of 152 participants enrolled between 2014 and 2018. Any women with newly diagnosed Stage I-III breast cancer scheduled to receive taxane-containing chemotherapy was eligible. The primary outcome was development of grade 2 or higher CIPN during chemotherapy graded by the clinician before each chemotherapy cycle (NCI-CTCAE v5 criteria). We measured p16 expression in peripheral blood T cells by qPCR before and at the end of chemotherapy. A multivariate model identified risk factors for CIPN and included taxane regimen type, p16Age Gap, a measure of discordance between chronological age and p16 expression, and p16 expression before chemotherapy. Participants with higher p16Age Gap-higher chronological age but lower p16 expression prior to chemotherapy - were at the highest risk. In addition, higher levels of p16 before treatment, regardless of patient age, conferred an increased risk of CIPN. Incidence of CIPN positively correlated with chemotherapy-induced increase in p16 expression, with the largest increase seen in participants with the lowest p16 expression before treatment. We have shown that p16 expression levels before treatment can identify patients at high risk for taxane-induced CIPN. If confirmed, p16 might help guide chemotherapy selection in early breast cancer.

Making National Cancer Institute-Designated Comprehensive Cancer Center Knowledge Accessible to Community Oncologists via an Online Tumor Board: Longitudinal Observational Study.

BACKGROUND: Expert knowledge is often shared among multidisciplinary academic teams at tumor boards (TBs) across the country, but these conversations exist in silos and do not reach the wider oncology community. OBJECTIVE: Using an oncologist-only question and answer (Q&A) website, we sought to document expert insights from TBs at National Cancer Institute-designated Comprehensive Cancer Centers (NCI-CCCs) to provide educational benefits to the oncology community. METHODS: We designed a process with the NCI-CCCs to document and share discussions from the TBs focused on areas of practice variation on theMednet, an interactive Q&A website of over 13,000 US oncologists. The faculty translated the TB discussions into concise, non-case-based Q&As on theMednet. Answers were peer reviewed and disseminated in email newsletters to registered oncologists. Reach and engagement were measured. Following each Q&A, a survey question asked how the TB Q&As impacted the readers' practice. RESULTS: A total of 23 breast, thoracic, gastrointestinal, and genitourinary programs from 16 NCI-CCC sites participated. Between December 2016 and July 2021, the faculty highlighted 368 questions from their TBs. Q&As were viewed 147,661 times by 7381 oncologists at 3515 institutions from all 50 states. A total of 277 (75%) Q&As were viewed every month. Of the 1063 responses to a survey question on how the Q&A affected clinicians' practices, 646 (61%) reported that it confirmed their current practice, 163 (20%) indicated that a Q&A would change their future practice, and 214 (15%) reported learning something new. CONCLUSIONS: Through an online Q&A platform, academics at the NCI-CCCs share knowledge outside the walls of academia with oncologists across the United States. Access to up-to-date expert knowledge can reassure clinicians' practices, significantly impact patient care in community practices, and be a source of new knowledge and education.

Clinical outcomes and Oncotype DX Breast Recurrence Score® in early-stage BRCA-associated hormone receptor-positive breast cancer.

BACKGROUND: BRCA-associated breast cancers tend to have distinctive features compared to sporadic breast cancers; further characterization can aid in optimizing treatment. METHODS: The study evaluated a patient cohort with early-stage estrogen receptor positive, HER2 negative invasive breast cancer who had Oncotype DX Breast Recurrence Score® analysis and genetic testing for hereditary breast and ovarian cancer syndrome. Data on patients and their breast cancers with outcomes were collected and analyzed. RESULTS: 745 patients were included, of whom 33 had pathogenic BRCA mutations (8 BRCA1, 25 BRCA2). Patients with BRCA mutations were younger and received more adjuvant chemotherapy, but less endocrine therapy and radiation therapy. BRCA-associated breast cancers had less progesterone receptor expression, higher nuclear grade, and higher Oncotype DX Breast Recurrence Scores® with median Recurrence Score® 29, compared to 16 in cancers without mutations (p < 0.0001). Breast cancer recurrence developed in 18% of patients with BRCA mutations and 9% of patient without mutations, although multivariate analysis of relapse-free survival was not significant, HR 1.519 (95% confidence interval [CI] 0.64-3.58; p = 0.3401). After adjusting for Recurrence Score®, overall survival by BRCA status was improved HR 0.448 (95% CI 0.06-3.34; p = 0.4333). CONCLUSIONS: BRCA-associated early-stage hormone receptor-positive breast cancers have higher Oncotype DX Breast Recurrence Score® compared to those without mutations. BRCA status did not significantly impact relapse-free survival and overall survival. Larger clinical trials are needed to further assess the findings, and if confirmed, could impact clinical management of BRCA-associated breast cancers.

Exploring and supporting older women's chemotherapy decision-making in early-stage breast cancer.

BACKGROUND: Few studies have focused on the therapeutic decision-making process in older adults with breast cancer. This study investigated older adult breast cancer patients' perspectives on neo/adjuvant chemotherapy, thereby identifying informational needs and preferences as patients navigate the treatment decision-making process. MATERIALS AND METHODS: Women ≥65 years diagnosed with early-stage breast cancer were recruited from an academic cancer center after deciding whether or not to receive neo/adjuvant chemotherapy. Participants completed surveys assessing sociodemographic characteristics, health literacy/numeracy, and shared decision making. They took part in individual semi-structured interviews to explore their perspectives, experiences, and values regarding treatment. Interviews were audio-recorded and transcribed. Transcripts were analyzed using the Sort and Sift, Think and Shift qualitative approach. Quantitative data was summarized using descriptive statistics. RESULTS: Of the 26 participants (age range 65-92 years; 81% non-Hispanic White; 72% ≥ college degree; 50% unmarried), 58% elected to undergo chemotherapy and 42% declined. The majority of participants had adequate health literacy/numeracy and engaged in shared decision-making. Thematic analysis revealed several commonalities regardless of the decision to undergo chemotherapy. Participants sought information regarding their disease/treatment. They referenced subjective experiences of friends/family members with cancer. Self-perception of health and the side effects of chemotherapy were also key factors. Participants placed importance on the maintenance of quality of life throughout treatment. CONCLUSIONS: Decision-making strategies in older patients were shaped by knowledge, values, and the anecdotal experiences of others. Results can inform the development of decision support tools for older patients and physicians to better facilitate the shared decision-making process.

Efficacy and safety of palbociclib in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with preexisting conditions: A post hoc analysis of PALOMA-2.

OBJECTIVE: In the PALOMA-2 trial, palbociclib in combination with letrozole prolonged progression-free survival (PFS) and exhibited an acceptable safety profile in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (ABC). This post hoc analysis of PALOMA-2 evaluated the efficacy and safety of palbociclib plus letrozole in patients with preexisting conditions grouped by Medical Dictionary for Regulatory Activities (MedDRA) System Organ Class (SOC). METHODS: Postmenopausal patients without prior treatment for ABC were randomized 2:1 to receive palbociclib (125 mg/d on a 3 weeks on/1 week off schedule) plus letrozole (2.5 mg/d, continuous) or placebo plus letrozole. Patients were grouped by the following MedDRA SOC preexisting conditions: gastrointestinal, musculoskeletal, metabolic, and vascular/cardiac. Median PFS was estimated by the Kaplan-Meier method, and treatment emergent adverse events (AEs) were compared between treatment arms within each preexisting condition subgroup. RESULTS: At baseline, 276 (41.4 %) patients had preexisting gastrointestinal disorders, 390 (58.6 %) had musculoskeletal disorders, 259 (38.9 %) had metabolic disorders, and 382 (57.4 %) had vascular/cardiac disorders. Baseline characteristics were similar between subgroups and between each arm within subgroups. Regardless of baseline preexisting condition, palbociclib plus letrozole prolonged PFS compared with placebo plus letrozole. Treatment-emergent AEs associated with palbociclib plus letrozole and dose modifications due to AEs were similar across preexisting condition subgroups. CONCLUSION: This post hoc analysis of PALOMA-2 demonstrated a favorable effect of palbociclib on PFS and a safety profile consistent with previous observations, regardless of underlying preexisting condition. Pfizer Inc (NCT01740427).

Phase I/II Trial of Exemestane, Ribociclib, and Everolimus in Women with HR+/HER2- Advanced Breast Cancer after Progression on CDK4/6 Inhibitors (TRINITI-1).

PURPOSE: Standard-of-care treatment for metastatic hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer includes endocrine therapy (ET) combined with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i). Optimal treatment after progression on CDK4/6i is unknown. The TRINITI-1 trial investigated ribociclib, a CDK4/6i that has recently demonstrated significant overall survival benefit in two phase III trials, in combination with everolimus and exemestane in patients with HR+, HER2- advanced breast cancer (ABC) after progression on a CDK4/6i. PATIENTS AND METHODS: This multicenter, open-label, single-arm, phase I/II study included patients with locally advanced/metastatic HR+/HER2- breast cancer. The primary endpoint was clinical benefit rate (CBR) at week 24 among patients with ET-refractory disease with progression on a CDK4/6i. Other endpoints included safety and biomarker analysis. RESULTS: Of 104 patients enrolled (phases I and II), 96 had prior CDK4/6i. Recommended phase II doses (all once daily days 1-28 of 28-day cycle) were ribociclib 300 mg, everolimus 2.5 mg, and exemestane 25 mg (group 1) and ribociclib 200 mg, everolimus 5 mg, and exemestane 25 mg (group 2). CBR among 95 efficacy-evaluable patients (phases I and II) at week 24 was 41.1% (95% confidence interval, 31.1-51.6), which met the primary endpoint (predetermined threshold: 10%). Common adverse events included neutropenia (69.2%) and stomatitis (40.4%). No new safety signals were observed; no grade 3/4 QTc prolongation was reported. CONCLUSIONS: Preliminary TRINITI-1 safety and efficacy results support further investigation of CDK4/6 blockade and targeting of the PI3K/AKT/mTOR signaling pathway in patients with ET-refractory HR+/HER2- ABC after progression on a CDK4/6i.

Impact of adjuvant endocrine therapy in older patients with comorbidities and estrogen receptor-positive, node-negative breast cancer-A National Cancer Database analysis.

BACKGROUND: Data are lacking about the benefit of adjuvant endocrine therapy (ET) in older patients with multiple comorbidities. The authors sought to determine the effect of ET on the survival of older patients who had multiple comorbidities and estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, pathologic node-negative (pN0) breast cancer. METHODS: Women aged ≥70 years in the National Cancer Database (2010-2014) with Charlson/Deyo comorbidity scores of 2 or 3 who had pathologic tumor (pT1)-pT3/pN0, ER-positive/HER2-negative breast cancer were divided into 2 cohorts: adjuvant ET and no ET. Propensity scores were used to match patients based on age, comorbidity score, facility type, pT classification, chemotherapy, surgery, and radiation therapy. A Cox proportional hazards model was used to estimate the effect of ET on overall survival (OS). RESULTS: In the nonmatched cohort (n = 3716), 72.8% of patients received ET (n = 2705), and 27.2% did not (n = 1011). The patients who received ET were younger (mean age, 76 vs 79 years; P < .001) and had higher rates of breast conservation compared with those who did not receive ET (lumpectomy plus radiation: 43.4% vs 23.8%, respectively; P < .001). In the matched cohort (n = 1972), the median OS was higher in the ET group (79.2 vs 67.7 months; P < .0001). In the adjusted analysis, ET was associated with improved survival (hazard ratio, 0.70; 95% CI, 0.59-0.83). CONCLUSIONS: In older patients who have pN0, ER-positive/HER2-negative breast cancer with comorbidities, adjuvant ET was associated with improved OS, which may have been overestimated given the confounders inherent in observational studies. To optimize outcomes in these patients, current standard recommendations should be considered stage-for-stage based on life expectancy and the level of tolerance to treatment.

Phase I Study of Elacestrant (RAD1901), a Novel Selective Estrogen Receptor Degrader, in ER-Positive, HER2-Negative Advanced Breast Cancer.

PURPOSE: This phase I study (RAD1901-005; NCT02338349) evaluated elacestrant, an investigational oral selective estrogen receptor degrader (SERD), in heavily pretreated women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer, including those with estrogen receptor gene alpha (ESR1) mutation. The primary objective was to determine the maximum tolerated dose and/or recommended phase II dose (RP2D). METHODS: The study consisted of a 3 + 3 design (elacestrant capsules) followed by expansion at RP2D (400-mg capsules, then 400-mg tablets) for the evaluation of safety and antitumor activity. Elacestrant was taken once daily until progression or intolerability. RESULTS: Of 57 postmenopausal women enrolled, 50 received RP2D (400 mg once daily): median age, 63 years; median three prior anticancer therapies, including cyclin-dependent kinase 4,6 inhibitors (CDK4/6i; 52%), SERD (52%), and ESR1 mutation (circulating tumor DNA; 50%). No dose-limiting toxicities occurred; the most common adverse events at RP2D (400-mg tablet; n = 24) were nausea (33.3%) and increased blood triglycerides and decreased blood phosphorus (25.0% each). Most adverse events were grade 1-2 in severity. The objective response rate was 19.4% (n = 31 evaluable patients receiving RP2D), 15.0% in patients with prior SERD, 16.7% in patients with prior CDK4/6i, and 33.3% in patients with ESR1 mutation (n = 5/15). The clinical benefit rate (24-week) was 42.6% overall (n = 47 patients receiving RP2D), 56.5% (n = 23, ESR1 mutation), and 30.4% (n = 23, prior CDK4/6i). Elacestrant clinical benefit was associated with decline in ESR1 mutant allele fraction. CONCLUSION: Elacestrant 400 mg orally once daily has an acceptable safety profile and demonstrated single-agent activity with confirmed partial responses in heavily pretreated patients with estrogen receptor-positive metastatic breast cancer. Notably, responses were observed in patients with ESR1 mutation as well as those with prior CDK4/6i and prior SERD. A phase III trial investigating elacestrant versus standard endocrine therapy is ongoing.

Patient-reported symptom severity, interference with daily activities, and adverse events in older and younger women receiving chemotherapy for early breast cancer.

BACKGROUND: To the authors' knowledge, it is unknown whether patient-reported symptom severity and symptom interference with daily activities differ between younger (aged <65 years) and older (aged ≥65 years) women receiving similar chemotherapy regimens for early breast cancer (EBC). METHODS: Study participants rated 17 side effects of chemotherapy regimens currently in use in clinical practice (2014-2019). RESULTS: Of 284 women with EBC (stage I-III), approximately 57% were aged <65 years and 43% were aged ≥65 years. For anthracycline-based regimens, a higher percentage of younger women reported moderate, severe, or very severe (MSVS) hot flashes (49% vs 18%) (P < .001). For nonanthracycline regimens, a higher percentage of younger women reported MSVS hot flashes (38% vs 19%) (P = .009) and a lower percentage reported MSVS arthralgia (28% vs 49%) (P = .005). With regard to symptom interference with daily activities, a higher percentage of younger women being treated with anthracycline-based regimens reported MSVS hot flashes (32% vs 7%) (P = .001) and myalgia (38% vs 18%) (P = .02). For nonanthracycline chemotherapy, a higher percentage of younger women reported MSVS interference for hot flashes (26% vs 9%) (P = .006) and lower percentages reported abdominal pain (13% vs 28%) (P = .02). Overall, there were no significant differences noted among younger versus older patients with regard to hospitalizations (19% vs 12%; P = .19), dose reductions (34% vs 31%; P = .50), dose delays (22% vs 25%; P = .59), or early treatment discontinuation (16% vs 16%; P = .9546). CONCLUSIONS: Older and younger women with EBC who were treated with identical chemotherapy regimens generally experienced similar levels of symptom severity, symptom-related interference with daily activities, and adverse events. LAY SUMMARY: In this study, women receiving chemotherapy for early breast cancer rated the severity of 17 symptoms and symptom interference with their activities of daily living. Older (aged ≥65 years) and younger (aged <65 years) women who received identical chemotherapy regimens generally experienced similar levels of symptom severity, symptom-related interference with daily activities, and adverse events.

A phase II study of Mirvetuximab Soravtansine in triple-negative breast cancer.

Folate receptor alpha (FRα) has been reported to be expressed in up to 80% of triple-negative breast cancers (TNBC) with limited expression in normal tissues, making it a promising therapeutic target. Mirvetuximab soravtansine (mirvetuximab-s) is an antibody drug conjugate which has shown promise in the treatment of FRα-positive solid tumors in early phase clinical trials. Herein, are the results of the first prospective phase II trial evaluating mirvetuximab-s in metastatic TNBC. Patients with advanced, FRα-positive TNBC were enrolled on this study. Mirvetuximab-s was administered at a dose of 6.0 mg/kg every 3 weeks. 96 patients with advanced TNBC consented for screening. FRα staining was performed on tumor tissue obtained from 80 patients. The rate of FRα positivity by immunohistochemistry was 10.0% (8/80). Two patients were treated on study, with best overall responses of stable disease in one and progressive disease in the other. Adverse events were consistent with earlier studies. The study was terminated early due to the low rate of FRα positivity in the screened patient population and lack of disease response in the two patients treated. The observed rate of FRα positivity was considerably lower than previously reported and none of the patients had a partial or complete response. Treatment with mirvetuximab-s should only be further explored in TNBC if an alternate biomarker strategy is developed for patient selection on the basis of additional preclinical data.

POLARIS: a prospective, multicenter, noninterventional study assessing palbociclib in hormone receptor-positive advanced breast cancer.

This report describes the rationale, purpose and design of the POLARIS study. POLARIS is an ongoing noninterventional, prospective, multicenter study. Female and male patients in the USA and Canada diagnosed with hormone receptor-positive/HER2-negative metastatic breast cancer were enrolled in the study and treated with the cyclin-dependent kinase 4/6 inhibitor palbociclib when hormone receptor-positive/HER2-negative metastatic breast cancer was deemed to be indicated by their physician. The study will provide real-world data on palbociclib prescribing and treatment patterns in routine clinical practice, associated clinical outcomes, treatment sequencing in the advanced/metastatic setting, patient quality of life and geriatric-specific assessments. The tumor genomic landscape in relation to clinical outcomes will be explored. POLARIS will identify benefits and side effects of palbociclib across multiple lines of therapy and in discrete subsets of patients. Clinical Trial Registration: NCT03280303 (ClinicalTrials.gov).

Delayed initiation of adjuvant chemotherapy in older women with breast cancer.

BACKGROUND: Adjuvant chemotherapy benefits early-stage breast cancer (BC) patients. Older women receive guideline-adherent treatment less frequently and experience treatment delays more frequently. We evaluated factors associated with delaying adjuvant chemotherapy and the delays' survival impact in a large population-based cohort of elderly BC patients. METHODS: Patients age >66 years diagnosed 2001-2015 with localized or regional BC were identified in the SEER-Medicare and Texas Cancer Registry-Medicare databases. Time from surgery to chemotherapy (TTC) was categorized into four groups: 0-30, 31-60, 61-90, and >90 days. We identified predictors of delays, estimated overall (OS) and BC-specific (BCSS) survival, and determined the association between TTC and outcome adjusting for other variables. RESULTS: Among 28,968 women (median age 71 years), median TTC was 43 days. 10.7% of patients experienced TTC >90 days. Older age, Black or Hispanic race/ethnicity, unmarried status, more comorbidities, hormone receptor-positivity, mastectomy, Oncotype DX testing, and full state buy-in were associated with increased risk of delay. Five-year OS estimates by TTC group were 0.82, 0.81, 0.80, and 0.74, respectively (p<.001). BCSS demonstrated a similar trend (p<.001). Chemotherapy delay was associated with worse OS (HR=1.33, 95%CI 1.25-1.40) and BCSS (HR=1.39, 95%CI 1.27-1.53). In subgroup analysis, delayed chemotherapy was associated with worse OS and BCSS among patients with hormone receptor-positive (HR=1.56, 95%CI 0.97-2.51), HER2-positive (HR=1.99, 95%CI 1.04-3.79), and triple-negative (HR=2.15, 95%CI 1.38-3.36) tumors. CONCLUSION: Chemotherapy delays are associated with worse survival in older BC patients. Providers should avoid delays and initiate chemotherapy ≤90 days after surgery regardless of patients' BC subtype or age.

Association of Chemotherapy With Survival in Elderly Patients With Multiple Comorbidities and Estrogen Receptor-Positive, Node-Positive Breast Cancer.

Importance: Breast cancer risk and comorbidities increase with age. Data are lacking on the association of adjuvant chemotherapy with survival in elderly patients with multiple comorbidities and node-positive breast cancer. Objective: To examine the association of chemotherapy with survival in elderly patients with multiple comorbidities and estrogen receptor-positive, node-positive breast cancer. Design, Setting, and Participants: This retrospective cohort study included patients in the US National Cancer Database who were 70 years or older; had a Charlson/Deyo comorbidity score of 2 or 3; had estrogen receptor-positive, ERBB2 (formerly HER2 or HER2/neu)-negative breast cancer; and underwent surgery for pathologic node-positive breast cancer from January 1, 2010, to December 31, 2014. Propensity scores were used to match patients receiving adjuvant chemotherapy with those not receiving adjuvant chemotherapy based on age, comorbidity score, facility type, facility location, pathologic T and N stage, and receipt of adjuvant endocrine and radiation therapy. Data analysis was performed from December 13, 2018, to April 28, 2020. Exposures: Chemotherapy. Main Outcomes and Measures: The association of adjuvant chemotherapy with overall survival was estimated using a double robust Cox proportional hazards regression model. Results: Of a total of 2 445 870 patients in the data set, 1592 patients (mean [SD] age, 77.5 [5.5] years; 1543 [96.9%] female) met the inclusion criteria and were included in the initial nonmatched analysis. Of these patients, 350 (22.0%) received chemotherapy and 1242 (78.0%) did not. Compared with patients who did not receive chemotherapy, patients who received chemotherapy were younger (mean age, 74 vs 78 years; P < .001), had larger primary tumors (pT3/T4 tumors: 72 [20.6%] vs 182 [14.7%]; P = .005), and had higher pathologic nodal burden (75 [21.4%] vs 81 [6.5%] with stage pN3 disease and 182 [52.0%] vs 936 [75.4%] with stage pN1 disease; P < .001). More patients who received chemotherapy also received other adjuvant treatments, including endocrine therapy (309 [88.3%] vs 1025 [82.5%]; P = .01) and radiation therapy (236 [67.4%] vs 540 [43.5%]; P < .001). In the matched cohort, with a median follow-up of 43.1 months (95% CI, 39.6-46.5 months), no statistically significant difference was found in median overall survival between the chemotherapy and no chemotherapy groups (78.9 months [95% CI, 78.9 months to not reached] vs 62.7 months [95% CI, 56.2 months to not reached]; P = .13). After adjustment for potential confounding factors, receipt of chemotherapy was associated with improved survival (hazard ratio, 0.67; 95% CI, 0.48-0.93; P = .02). Conclusions and Relevance: This cohort study found that in node-positive, estrogen receptor-positive elderly patients with breast cancer and multiple comorbidities, receipt of chemotherapy was associated with improved overall survival. Despite attempts to adjust for selection bias, these findings suggest that physicians carefully selected patients likely to derive treatment benefit from adjuvant chemotherapy based on certain unmeasured variables. A standardized, multidisciplinary approach to care may be associated with long-term treatment outcomes in this subset of the population.