Faculty Bibliography

PURPOSE/OBJECTIVE:Endocrine therapy (ET) is an effective strategy to treat hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) but nearly all patients eventually progress. Our goal was to develop and validate a web-based clinical calculator for predicting disease outcomes in women with HR+ABC who are candidates for receiving first-line single-agent ET. METHODS:The meta-database comprises 891 patient-level data from the control arms of five contemporary clinical trials where patients received first-line single-agent ET (either aromatase inhibitor or fulvestrant) for ABC. Risk models were constructed for predicting 24-months progression-free survival (PFS-24) and 24-months overall survival (OS-24). Final models were internally validated for calibration and discrimination using ten-fold cross-validation. RESULTS:Higher number of sites of metastases, measurable disease, younger age, lower body mass index, negative PR status, and prior endocrine therapy were associated with worse PFS. Final PFS and OS models were well-calibrated and associated with cross-validated time-dependent area under the curve (AUC) of 0.61 and 0.62, respectively. CONCLUSIONS:The proposed ABC calculator is internally valid and can accurately predict disease outcomes. It may be used to predict patient prognosis, aid planning of first-line treatment strategies, and facilitate risk stratification for future clinical trials in patients with HR+ABC. Future validation of the proposed models in independent patient cohorts is warranted.

PURPOSE/OBJECTIVE:To assess the feasibility and efficacy of a non-hormonal hyaluronic acid (HLA) vaginal gel in improving vulvovaginal estrogen-deprivation symptoms in postmenopausal women with a history of hormone receptor-positive (HR+) cancer. METHODS:For this single-arm, prospective longitudinal trial, we identified disease-free patients with a history of HR+ breast cancer treated with aromatase inhibitors or HR+ endometrial cancer treated with surgery and postoperative radiation. Participants used HLA daily for the first 2 weeks, and then 3×/week until weeks 12-14; dosage was then increased to 5×/week for non-responders. Vulvovaginal symptoms and pH were assessed at 4 time points (baseline [T1], 4-6 weeks [T2], 12-14 weeks [T3], 22-24 weeks [T4]) with clinical evaluation, the Vaginal Assessment Scale (VAS), Vulvar Assessment Scale (VuAS), Female Sexual Function Index (FSFI), and Menopausal Symptom Checklist (MSCL). RESULTS:Of 101 patients, mean age was 55 years (range, 31-78), 68% (n = 69) were partnered, and 60% (n = 61) were sexually active. In linear mixed models, VAS/VuAS scores significantly improved at all assessment points (all p < 0.001). MSCL scores similarly improved (all p < 0.001). FSFI scores significantly improved from T1 to T2 (p < 0.03), T3 (p < 0.001), and T4 (p < 0.001). Severe vaginal pH (> 6.5) decreased from 26% at T1 to 19% at T4 (p = 0.18). CONCLUSIONS:HLA moisturization improved vulvovaginal health/sexual function of cancer survivors. While HLA administration 1-2×/week is recommended for women in natural menopause, a 3-5×/week schedule appears to be more effective for symptom relief in cancer survivors.

PURPOSE/OBJECTIVE:To determine the longitudinal impact of adjuvant chemotherapy and tamoxifen-only treatments on the reproductive potential of women with breast cancer by using a sensitive ovarian reserve marker anti-Mullerian hormone (AMH) as a surrogate. METHODS:One-hundred-and-forty-two women with a primary diagnosis of breast cancer were prospectively followed with serum AMH assessments before the initiation, and 12, 18 and 24 months after the completion of adjuvant chemotherapy or the start of tamoxifen-only treatment. The chemotherapy regimens were classified into Anthracycline-Cyclophosphamide-based (AC-based) and Cyclophosphamide-Methotrexate + 5-Fluorouracil (CMF). Longitudinal data were analyzed by mixed effects model for treatment effects over time, adjusting for baseline age and BMI. RESULTS:Both chemotherapy regimens resulted in significant decline in ovarian reserve compared to the tamoxifen-only treatment (p < 0.0001 either regimen vs. tamoxifen for overall trend). AMH levels sharply declined at 12 months but did not show a significant recovery from 12 to 18 and 18 to 24 months after the completion of AC-based or CMF regimens. The degree of decline did not differ between the two chemotherapy groups (p = 0.53). In contrast, tamoxifen-only treatment did not significantly alter the age-adjusted serum AMH levels over the 24-month follow up. Likewise, the use of adjuvant tamoxifen following AC-based regimens did not affect AMH recovery. CONCLUSIONS:Both AC-based regimens and CMF significantly compromise ovarian reserve, without a recovery beyond 12 months post-chemotherapy. In contrast, tamoxifen-only treatment does not seem to alter ovarian reserve. These data indicate that the commonly used chemotherapy regimens but not the hormonal therapy compromise future reproductive potential.

PURPOSE/OBJECTIVE:In MONARCH 1 (NCT02102490), single-agent abemaciclib demonstrated promising efficacy activity and tolerability in a population of heavily pretreated women with refractory HR+, HER2- metastatic breast cancer (MBC). To help interpret these results and put in clinical context, we compared overall survival (OS) and duration of therapy (DoT) between MONARCH 1 and a real-world single-agent chemotherapy cohort. METHODS:The real-world chemotherapy cohort was created from a Flatiron Health electronic health records-derived database based on key eligibility criteria from MONARCH 1. The chemotherapies included in the cohort were single-agent capecitabine, gemcitabine, eribulin, or vinorelbine. Results were adjusted for baseline demographics and clinical differences using Mahalanobis distance matching (primary analysis) and entropy balancing (sensitivity analysis). OS and DoT were analyzed using the Kaplan-Meier method and Cox proportional hazards regression. RESULTS:A real-world single-agent chemotherapy cohort (n = 281) with eligibility criteria similar to the MONARCH 1 population (n = 132) was identified. The MONARCH 1 (n = 108) cohort was matched to the real-world chemotherapy cohort (n = 108). Median OS was 22.3 months in the abemaciclib arm versus 13.6 months in the matched real-world chemotherapy cohort with an estimated hazard ratio (HR) of 0.54. The median DoT was 4.1 months in MONARCH 1 compared to 2.9 months in the real-world chemotherapy cohort with HR of 0.76. CONCLUSIONS:This study demonstrates an approach to create a real-world chemotherapy cohort suitable to serve as a comparator for trial data. These exploratory results suggest a survival advantage and place the benefit of abemaciclib monotherapy in clinical context.

OBJECTIVE:To assess whether woman who have BRCA mutations (WBM) experience more declines in ovarian reserve after chemotherapy treatment, as it induces oocyte death by deoxyribonucleic acid (DNA) damage, and BRCA mutations result in DNA damage repair deficiency. DESIGN/METHODS:Longitudinal cohort study. SETTING/METHODS:Academic centers. PATIENT(S)/METHODS:Of the 235 enrolled, 108 evaluable women with breast cancer were stratified into those never tested (negative family history; n = 35) and those negative (n = 59) or positive (n = 14) for a pathogenic BRCA mutation. INTERVENTION(S)/METHODS:Sera were longitudinally obtained before and 12-24 months after chemotherapy tratment, assayed for antimüllerian hormone (AMH), and adjusted for age at sample collection. MAIN OUTCOME MEASURE(S)/METHODS:Ovarian recovery, defined as the geometric mean of the after chemotherapy age-adjusted AMH levels compared with baseline levels. RESULT(S)/RESULTS:Compared with the controls, the before chemotherapy treatment AMH levels were 24% and 34% lower in those negative or positive for BRCA mutations, consistent with accelerated ovarian aging in WBM. The WBM had a threefold difference in AMH recovery after chemotherapy treatment (1.6%), when compared with BRCA negative (3.7%) and untested/low risk controls (5.2%). Limiting the analysis to the most common regimen, doxorubicin and cyclophosphamide followed by paclitaxel, showed similar results. These findings were mechanistically confirmed in an in vitro mouse oocyte BRCA knockdown bioassay, which showed that BRCA deficiency results in increased oocyte susceptibility to doxorubicin. CONCLUSION(S)/CONCLUSIONS:Women who have pathogenic BRCA mutations are more likely to lose ovarian reserve after chemotherapy treatment, suggesting an emphasis on fertility preservation. Furthermore, our findings generate the hypothesis that DNA repair deficiency is a shared mechanism between aging, infertility, and cancer. CLINICAL TRIAL REGISTRATION NUMBER/BACKGROUND:NCT00823654.

Alpelisib is a selective inhibitor of PI3Kα, shown to improve outcomes for PIK3CA mutant, hormone receptor positive (HR+) metastatic breast cancers (MBC) when combined with antiestrogen therapy. To uncover mechanisms of resistance, we conducted a detailed, longitudinal analysis of tumor and plasma circulating tumor DNA among such patients from a phase I/II trial combining alpelisib with an aromatase inhibitor (AI) (NCT01870505). The trial's primary objective was to establish safety with maculopapular rash emerging as the most common grade 3 adverse event (33%). Among 44 evaluable patients, the observed clinical benefit rate was 52%. Correlating genetic alterations with outcome, we identified loss-of-function PTEN mutations in 25% of patients with resistance. ESR1 activating mutations also expanded in number and allele fraction during treatment and were associated with resistance. These data indicate that genomic alterations that mediate resistance to alpelisib or antiestrogen may promote disease progression and highlight PTEN loss as a recurrent mechanism of resistance to PI3Kα inhibition.

OBJECTIVES/OBJECTIVE:The National Cancer Institute (NCI) National Clinical Trials Network performs phase II and III clinical trials, which increasingly rely on the submission of diagnostic formalin-fixed, paraffin-embedded tissue blocks for biomarker assessment. Simultaneously, advances in precision oncology require that clinical centers maintain diagnostic specimens for ancillary, standard-of-care diagnostics. This has caused tissue blocks to become a limited resource for advancing the NCI clinical trial enterprise and the practice of modern molecular pathology. METHODS:The NCI convened a 1-day workshop of multidisciplined experts to discuss barriers and strategic solutions to facilitate diagnostic block submission for clinical trial science, from the perspective of patient advocates, legal experts, pathologists, and clinical oncologists. RESULTS:The expert views and opinions were carefully noted and reported. CONCLUSIONS:Recommendations were proposed to reduce institutional barriers and to assist organizations in developing clear policies regarding diagnostic block submission for clinical trials.

Activating mutations in PIK3CA are frequent in human breast cancer, and phosphoinositide 3-kinase alpha (PI3Kα) inhibitors have been approved for therapy. To characterize determinants of sensitivity to these agents, we analyzed PIK3CA-mutant cancer genomes and observed the presence of multiple PIK3CA mutations in 12 to 15% of breast cancers and other tumor types, most of which (95%) are double mutations. Double PIK3CA mutations are in cis on the same allele and result in increased PI3K activity, enhanced downstream signaling, increased cell proliferation, and tumor growth. The biochemical mechanisms of dual mutations include increased disruption of p110α binding to the inhibitory subunit p85α, which relieves its catalytic inhibition, and increased p110α membrane lipid binding. Double PIK3CA mutations predict increased sensitivity to PI3Kα inhibitors compared with single-hotspot mutations.

BACKGROUND:Randomised trials comparing the efficacy of standard endocrine therapy (ET) versus experimental ET + bevacizumab (Bev) in 1st line hormone receptor-positive patients with metastatic breast cancer have thus far shown conflicting results. PATIENTS AND METHODS/METHODS:We pooled data from two similar phase III randomised trials of ET ± Bev (LEA and Cancer and Leukemia Group B 40503) to increase precision in estimating treatment effect. Primary end-point was progression-free survival (PFS). Secondary end-points were overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety. Exploratory analyses were performed within subgroups defined by patients with recurrent disease, de novo disease, prior endocrine sensitivity or resistance and reported grades III-IV hypertension and proteinuria. RESULTS:The pooled sample consisted of 749 patients randomised to ET or ET + Bev. Median PFS was 14.3 months for ET versus 19 months for ET + Bev (unadjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.66-0.91; p < 0.01). ORR and CBR with ET and ET + Bev were 40 versus 61% (p < 0.01) and 64 versus 77% (p < 0.01), respectively. There was no difference in OS (HR 0.96; 95% CI 0.77-1.18; p = 0.68). PFS was superior for ET + Bev for endocrine-sensitive patients (HR 0.68; 95% CI 0.53-0.89; p = 0.004). Grade III-IV hypertension (2.2 versus 20.1%), proteinuria (0 versus 9.3%), cardiovascular (0.5 versus 4.2%) and liver events (0 versus 2.9%) were significantly higher for ET + Bev (all p < 0.01). Hypertension and proteinuria were not predictors of efficacy (interaction test p = 0.33). CONCLUSION/CONCLUSIONS:The addition of Bev to ET increased PFS overall and in endocrine-sensitive patients but not OS at the expense of significant additional toxicity. TRIALS REGISTRATION/BACKGROUND:ClinicalTrial.Gov NCT00545077 and NCT00601900.