Anastrozole dose escalation for optimal estrogen suppression in postmenopausal early-stage breast cancer: A prospective trial.

BACKGROUND: We previously reported that postmenopausal women with ER+ breast cancer (BC) receiving adjuvant anastrozole 1 mg/day (ANA1) with estrone (E1) ≥1.3 pg/mL and estradiol (E2) ≥0.5 (inadequate estrogen suppression [IES]) had a 3.0-fold increased risk of a BC event. The objective of this study was to determine if increasing anastrozole to 10 mg/day (ANA10) could result in adequate estrogen suppression (AES: E1 <1.3 pg/mL and/or E2 <0.5) among those with IES on ANA1. METHODS: Postmenopausal women with ER+ BC planning to receive adjuvant ANA1 were eligible. E1 and E2 were assessed pre- and post-8-10 weeks of ANA1. Those with IES were switched to 8-10 week cycles of ANA10 followed by letrozole 2.5 mg/day. E1 and E2 were assessed after each cycle. Anastrozole concentrations were measured post-ANA1 and post-ANA10. Primary analyses included patients who documented taking at least 80% of planned treatment (adherent cohort). RESULTS: 132 (84.6%) of 156 eligible patients were ANA1-adherent. IES occurred in 40 (30.3%) adherent patients. 25 (78.1%) of 32 patients who began ANA10 were adherent, and AES was achieved in 19 (76.0%; 90%CI: 58.1-89.0%) patients. Anastrozole concentrations post-ANA1 and post-ANA10 did not differ by estrogen suppression status among adherent patients. AES was maintained/attained in 21 (91.3%) of 23 letrozole-adherent patients. CONCLUSIONS: Approximately 30% of ANA1-adherent patients had IES. Among those who switched to ANA10 and were adherent, 76% had AES. Further studies are required to validate emerging data that ANA1 results in IES for some patients and to determine the clinical benefit of switching to ANA10 or an alternative AI.

Preparing Hematology/Oncology Fellows for Success: Implementing an Annual Career Development and Research Retreat.

Multiple factors, including job satisfaction, personality traits, and training experiences, influence the career trajectory of hematology/oncology fellows. In an effort to expose hematology/oncology fellows to (1) the various careers in oncology, (2) a diverse group of speakers for future mentorship, and (3) research opportunities, and grant writing experience, we established an annual career development and research retreat. During the retreat, we engaged speakers who covered a range of career trajectories, including academic, private practice, industry, government, and administrative paths. We introduced clinicians and researchers with a track record of providing top-notch mentorship to fellows with aligning interests and detailed research opportunities and grant writing. The sessions were led by senior fellows, and we adopted an in-person and virtual hybrid model to allow speakers from various institutions to participate. Feedback from participants, as gathered through surveys, indicated positive responses: all respondents reported that this retreat was "extremely" or "very helpful," and a majority expressed their intent to pursue academic careers. The curriculum and structure of this retreat may help to inform the development of fellowship career development and research retreats at other institutions.

Effect of Metformin Versus Placebo on New Primary Cancers in Canadian Cancer Trials Group MA.32: A Secondary Analysis of a Phase III Randomized Double-Blind Trial in Early Breast Cancer.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Metformin has been associated with lower cancer risk in epidemiologic and preclinical research. In the MA.32 randomized adjuvant breast cancer trial, metformin (v placebo) did not affect invasive disease-free or overall survival. Here, we report metformin effects on the risk of new cancer. Between 2010 and 2013, 3,649 patients with breast cancer younger than 75 years without diabetes with high-risk T1-3, N0-3 M0 breast cancer (any estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2) were randomly assigned to metformin 850 mg orally twice a day or placebo twice a day for 5 years. New primary invasive cancers (outside the ipsilateral breast) developing as a first event were identified. Time to events was described by the competing risks method; two-sided likelihood ratio tests adjusting for age, BMI, smoking, and alcohol intake were used to compare metformin versus placebo arms. A total of 184 patients developed new invasive cancers: 102 metformin and 82 placebo, hazard ratio (HR), 1.25; 95% CI, 0.94 to 1.68; P = .13. These included 48 contralateral invasive breast cancers (27 metformin v 21 placebo), HR, 1.29; 95% CI, 0.72 to 2.27; P = .40 and 136 new nonbreast primary cancers (75 metformin v 61 placebo), HR, 1.24; 95% CI, 0.88 to 1.74; P = .21. Metformin did not reduce the risk of new cancer development in these nondiabetic patients with breast cancer.

A phase II study of bevacizumab and temsirolimus in advanced extra-pancreatic neuroendocrine tumors.

We assessed the efficacy and safety of combining bevacizumab with temsirolimus in patients with advanced extra-pancreatic neuroendocrine tumors. This NCI-sponsored multicenter, open-label, phase II study (NCT01010126) enrolled patients with advanced, recurrent, or metastatic extra-pancreatic neuroendocrine tumors. All patients were treated with temsirolimus and bevacizumab until disease progression or unacceptable toxicity. Temsirolimus 25 mg was administered i.v. on days 1, 8, 15, and 22 and bevacizumab 10 mg/kg i.v. on days 1 and 15 of a 4-week cycle. Discontinuation of temsirolimus or bevacizumab did not require discontinuation of the other agent. The primary endpoints were objective response rate and 6-month progression-free survival rate. Fifty-nine patients were enrolled in this study, and 54 were evaluated for efficacy and adverse events. While median progression-free survival was 7.1 months, the median duration of treatment with temsirolimus was 3.9 months and that with bevacizumab was 3.5 months. The objective response rate of combination therapy was 2%, and 6-month progression-free survival was 48%. The most frequently reported grade 3-4 adverse events included fatigue (13%), hypertension (13%), and bleeding (13%). Close to 54% of the patients discontinued treatment due to adverse events, refusal of further treatment, or treatment delays. Three deaths occurred in the study, of which two were due to treatment-related bowel perforations. Given the minimal efficacy and increased toxicity seen with the combination of bevacizumab and temsirolimus, we do not recommend the use of this regimen in patients with advanced extra-pancreatic neuroendocrine tumors.

Efficacy of first-line checkpoint inhibitors in combination with chemotherapy in high-grade extrapulmonary metastatic neuroendocrine carcinomas.

Poorly differentiated extrapulmonary neuroendocrine carcinomas (EP NECs) are aggressive cancers characterized by a high Ki-67 index, rapid tumor growth and poor survival, and are subdivided into small and large cell carcinoma. For small cell carcinoma of the lung, a pulmonary NEC, the combination of cytotoxic chemotherapy (CTX) and a checkpoint inhibitor (CPI) is considered standard therapy and superior to CTX alone. EP NECs are typically treated with platinum-based regimens, some clinicians have adopted the addition of a CPI to CTX based on data from trials in patients with small cell carcinoma of the lung. In this retrospective study of EP NECs, we report 38 patients treated with standard first-line CTX and 19 patients treated with CTX plus CPI. We did not observe any additional benefit of adding CPI to CTX in this cohort.

Adherence to Cancer Prevention Lifestyle Recommendations Before, During, and 2 Years After Treatment for High-risk Breast Cancer.

Importance: The American Institute for Cancer Research and American Cancer Society regularly publish modifiable lifestyle recommendations for cancer prevention. Whether these recommendations have an impact on high-risk breast cancer survival remains unknown. Objective: To investigate whether adherence to cancer prevention recommendations before, during, and 1 and 2 years after breast cancer treatment was associated with disease recurrence or mortality. Design, Setting, and Participants: The Diet, Exercise, Lifestyles, and Cancer Prognosis Study (DELCaP) was a prospective, observational cohort study designed to assess lifestyles before diagnosis, during treatment, and at 1 and 2 years after treatment completion, implemented ancillary to the Southwest Oncology Group (SWOG) S0221 trial, a multicenter trial that compared chemotherapy regimens in breast cancer. Participants were chemotherapy-naive patients with pathologic stage I to III high-risk breast cancer, defined as node-positive disease with hormone receptor-negative tumors larger than 1 cm or any tumor larger than 2 cm. Patients with poor performance status and comorbidities were excluded from S0221. The study was conducted from January 1, 2005, to December 31, 2010; mean (SD) follow-up time for those not experiencing an event was 7.7 (2.1) years through December 31, 2018. The analyses reported herein were performed from March 2022 to January 2023. Exposure: An aggregated lifestyle index score comprising data from 4 time points and 7 lifestyles, including (1) physical activity, (2) body mass index, (3) fruit and vegetable consumption, (4) red and processed meat intake, (5) sugar-sweetened beverage consumption, (6) alcohol consumption, and (7) smoking. Higher scores indicated healthier lifestyle. Main Outcomes and Measures: Disease recurrence and all-cause mortality. Results: A total of 1340 women (mean [SD] age, 51.3 [9.9] years) completed the baseline questionnaire. Most patients were diagnosed with hormone-receptor positive breast cancer (873 [65.3%]) and completed some education beyond high school (954 [71.2%]). In time-dependent multivariable analyses, patients with highest vs lowest lifestyle index scores experienced a 37.0% reduction in disease recurrence (hazard ratio, 0.63; 95% CI, 0.48-0.82) and a 58.0% reduction in mortality (hazard ratio, 0.42; 95% CI, 0.30-0.59). Conclusions and Relevance: In this observational study of patients with high-risk breast cancer, strongest collective adherence to cancer prevention lifestyle recommendations was associated with significant reductions in disease recurrence and mortality. Education and implementation strategies to help patients adhere to cancer prevention recommendations throughout the cancer care continuum may be warranted in breast cancer.

Evaluation of Hepatotoxicity from Peptide Receptor Radionuclide Therapy in Patients with Gastroenteropancreatic Neuroendocrine Tumors and a Very High Liver Tumor Burden.

The aim of the current study was to describe the risk of hepatotoxicity for patients with gastroenteropancreatic neuroendocrine tumors undergoing peptide receptor radionuclide therapy (PRRT) with a very high liver tumor burden, defined as tumor involving more than 75% of the liver. Methods: We conducted a retrospective analysis of 371 patients who received at least 1 cycle of 177Lu-DOTATATE at Mayo Clinic for advanced gastroenteropancreatic neuroendocrine tumors. We identified 15 total patients with more than 75% liver involvement on 68Ga-DOTATATE PET/CT and with either a contrast-enhanced abdominal MRI or dual-phase abdominal CT examination. Results: Of the 15 patients with more than 75% liver involvement, 1 experienced hepatotoxicity (i.e., worsening liver enzymes or bilirubin) as defined by the Common Terminology Criteria for Adverse Events, version 5.0. No patients had grade 3-5 hepatotoxicity (i.e., clinical signs of liver failure). Conclusion: When considering the risk of liver injury from PRRT due to burden of disease, our data suggest that PRRT may be a safe option in patients with more than 75% liver involvement. Future efforts should be made to determine the safety profile of PRRT in patients with varying degrees of liver involvement.

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.

Clinical management of metastatic hormone receptor-positive, HER2-negative breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study.

PURPOSE: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is), in combination with endocrine therapy (ET), are standard either in the first (1L) or second-line (2L) setting for the treatment of hormone receptor (HR) positive, HER2-negative metastatic breast cancer (MBC). However, the optimal sequencing of treatments after progression on CDK4/6i remains unknown. We performed a single-institution analysis to identify treatments and outcomes after progression on a CDK4/6i. METHODS: We identified patients with HR-positive, HER2-negative MBC prescribed a CDK4/6i in the 1L or 2L settings from December 2014 to February 2018 at Mayo Clinic in Rochester, Minnesota. Outcomes were collected through September 30, 2020. RESULTS: Palbociclib, in combination with letrozole or fulvestrant, was the most prescribed CDK4/6i. The 1L and 2L CDK4/6i cohorts exhibited comparable overall survival (OS), but progression-free survival (PFS) was longer in the 1L than the 2L cohort [28.2 months (95% CI 19.6-34.9) vs 19.8 months (95% CI 15.7-29.6)]. The most common post-CDK4/6i treatments were PI3K/mTOR inhibitors (PI3K/mTORi), single-agent ET, or chemotherapy. PFS in the 1L CDK4/6i cohort following PI3K/mTORi was 8.5 months (95% CI 5.5 months-NE), single-agent ET was 6.0 months (95% CI 3.3-14.0 months), and chemotherapy PFS was 5.4 months (95% CI 3.3 months-NE). CONCLUSIONS: Following progression on a CDK 4/6i, mPFS was short, with similar PFS times comparing chemotherapy and ET, with slightly longer PFS for targeted strategies (PI3K/mTOR). These results highlight a major need to better understand the mechanisms of CDK4/6i resistance and identify new therapeutic strategies for these patients.

Effect of Metformin vs Placebo on Invasive Disease-Free Survival in Patients With Breast Cancer: The MA.32 Randomized Clinical Trial.

Importance: Metformin, a biguanide commonly used to treat type 2 diabetes, has been associated with potential beneficial effects across breast cancer subtypes in observational and preclinical studies. Objective: To determine whether the administration of adjuvant metformin (vs placebo) to patients with breast cancer without diabetes improves outcomes. Design, Setting, and Participants: MA.32, a phase 3 randomized, placebo-controlled, double-blind trial, conducted in Canada, Switzerland, US, and UK, enrolled 3649 patients with high-risk nonmetastatic breast cancer receiving standard therapy between August 2010 and March 2013, with follow-up to October 2020. Interventions: Patients were randomized (stratified for hormone receptor [estrogen receptor and/or progesterone receptor {ER/PgR}] status, positive vs negative; body mass index, ≤30 vs >30; human epidermal growth factor receptor 2 [ERBB2, formerly HER2 or HER2/neu], positive vs negative; and any vs no chemotherapy) to 850 mg of oral metformin twice a day (n = 1824) or oral placebo twice a day (n = 1825) for 5 years. Main Outcomes and Measures: The primary outcome was invasive disease-free survival in hormone receptor-positive breast cancer. Of the 8 secondary outcomes, overall survival, distant relapse-free survival, and breast cancer-free interval were analyzed. Results: Of the 3649 randomized patients (mean age, 52.4 years; 3643 women [99.8%]), all (100%) were included in analyses. After a second interim analysis, futility was declared for patients who were ER/PgR-, so the primary analysis was conducted for 2533 patients who were ER/PgR+. The median duration of follow-up in the ER/PgR+ group was 96.2 months (range, 0.2-121 months). Invasive disease-free survival events occurred in 465 patients who were ER/PgR+. The incidence rates for invasive disease-free survival events were 2.78 per 100 patient-years in the metformin group vs 2.74 per 100 patient-years in the placebo group (hazard ratio [HR], 1.01; 95% CI, 0.84-1.21; P = .93), and the incidence rates for death were 1.46 per 100 patient-years in the metformin group vs 1.32 per 100 patient-years in the placebo group (HR, 1.10; 95% CI, 0.86-1.41; P = .47). Among patients who were ER/PgR-, followed up for a median of 94.1 months, incidence of invasive disease-free survival events was 3.58 vs 3.60 per 100 patient-years, respectively (HR, 1.01; 95% CI, 0.79-1.30; P = .92). None of the 3 secondary outcomes analyzed in the ER/PgR+ group had statistically significant differences. Grade 3 nonhematological toxic events occurred more frequently in patients taking metformin than in patients taking placebo (21.5% vs 17.5%, respectively, P = .003). The most common grade 3 or higher adverse events in the metformin vs placebo groups were hypertension (2.4% vs 1.9%), irregular menses (1.5% vs 1.4%), and diarrhea (1.9% vs 7.0%). Conclusions and Relevance: Among patients with high-risk operable breast cancer without diabetes, the addition of metformin vs placebo to standard breast cancer treatment did not significantly improve invasive disease-free survival. Trial Registration: ClinicalTrials.gov Identifier: NCT01101438.

Survival and Incidence Patterns of Pancreatic Neuroendocrine Tumors Over the Last 2 Decades: A SEER Database Analysis.

BACKGROUND: Pancreatic neuroendocrine tumors (pNETs) are rare cancers with outcomes determined by multiple factors including grade, stage, and clinical presentation. In this study, we aimed to determine the prognosis of patients with pNETs using a large population-based database. MATERIALS AND METHODS: In this population-based study, we identified patients with pNETs from the SEER 18 registry (2000-2016) using a combination of ICD-O-3 and histology codes. We calculated age-adjusted incidence rates using SEER*Stat 8.3.5. In addition, we analyzed overall survival (OS) using the Kaplan-Meier method, and investigated prognostic factors using a multivariable Cox proportional hazards model. RESULTS: A total of 8944 pNETs patients were identified. Annual incidence rates increased from 0.27 to 1.00 per 100 000. This was largely explained by an increase in number of patients diagnosed with localized disease in more recent years (2012-2016). Median OS was 68 months (95% CI [64, 73]) and 5-year OS rates in localized, regional, and metastatic disease were 83%, 67%, and 28%, respectively. There was a significant improvement in OS for patients diagnosed between 2009 and 2016 (median OS 85 months) compared with those diagnosed between 2000 and 2008 (median OS 46 months) (HR 0.66; 95% CI [0.62, 0.70]). This improvement in OS was consistent across all stages. CONCLUSIONS AND RELEVANCE: This study shows a steady increase pNETs incidence with notable stage migration to earlier stages in recent years. This increase in incidence is accompanied by a significant improvement in survival across different disease stages.

Pilot Study Characterizing the Hematology-Oncology Fellow Job Search Process: Tools Used and Identification of Potential New Resources.

While the search for post-fellowship employment is an essential part of early career development, little is known about the tools and techniques fellows use during their job search and the specific challenges they face during the process. In this pilot survey study of hematology-oncology (HO) fellows at a large academic training program, the majority of 20 respondents (43% of all fellows) reported a plan to specialize in medical oncology, and most planned to practice in an academic setting. Fellows who had started the job search process reported using several tools/techniques including online job centers and email distribution lists, word of mouth, prior connections with other institutions, and their HO fellowship program leadership, and most reported that their current institution provided help for their job search in at least one way. Job search challenges included learning about available positions, lack of mentorship on the process, lack of sufficient time for the process, and lack of preparation for negotiation. Fellows suggested additional resources that could be helpful to future job searchers including access to information about prior HO fellowship graduates, training in negotiation and interviewing, and career development mentorship. We plan to use this information to expand our own Career Development program for fellows enacting many of these suggestions, and we encourage the use of this information as pilot data for the development of larger studies across other medical and surgical specialties.

Assessment of Discrimination, Bias, and Inclusion in a United States Hematology and Oncology Fellowship Program.

Importance: Medical trainees frequently experience discrimination. Understanding their experiences is essential to improving learning environments. Objective: To characterize trainee experiences of discrimination and inclusion to inform graduate medical education (GME) policies. Design, Setting, and Participants: This qualitative study used an anonymous telephone interview technique to gather data from hematology and oncology fellows. All current trainees and recent graduates were eligible. Interviews were conducted anonymously with interviewer and participant in separate locations and recorded and transcribed. Data were analyzed in an iterative process into major themes using a general inductive analysis approach. Demographic information was obtained via anonymous survey. Data collection and analysis were conducted from July 2018 to November 2019. Main Outcomes and Measures: Emergent themes illustrating bias and inclusion in a GME program. Results: Among 34 fellows and recent graduates who were approached for this study, 20 consented and 17 were interviewed. Of those interviewed, 10 were men, and the median (range) age was 32 (29-53) years. The racial and ethnic distribution included 6 Asian individuals, 2 Black individuals, 3 Hispanic individuals, 2 multiracial individuals, and 4 White individuals. All fellows reported having experienced and/or witnessed discriminatory behavior. The themes elucidated were (1) foreign fellows perceived as outsiders, (2) US citizens feeling alien at home, (3) gender role-typing, (4) perception of futility of reporting, (5) diversity and inclusion, and (6) coping strategies. The majority of reported biases were from patients. Only 1 trainee reported any incidents. Reasons for not reporting were difficulty characterizing discrimination and doubt action would occur. Participants reported that diversity of cotrainees, involvement in committees, and open discussions promoted inclusivity. Conclusions and Relevance: In this study, reports of discriminatory behavior toward trainees were common. The anonymous hotline methodology cultivated a safe environment for candid discussions. These findings suggest that GME programs should assess their learning climate regarding bias and inclusivity anonymously and develop processes to support trainees.

Cancer Antigen 15-3/Mucin 1 Levels in CCTG MA.32: A Breast Cancer Randomized Trial of Metformin vs Placebo.

Background: Circulating levels of cancer antigen (CA) 15-3, a tumor marker and regulator of cellular metabolism, were reduced by metformin in a nonrandomized neoadjuvant study. We examined the effects of metformin (vs placebo) on CA 15-3 in participants of MA.32, a phase III randomized trial in early-stage breast cancer. Methods: A total of 3649 patients with T1-3, N0-3, M0 breast cancer were randomly assigned; pretreatment and 6-month on-treatment fasting plasma were centrally assayed for CA 15-3. Genomic DNA was analyzed for the rs11212617 single nucleotide polymorphism. Absolute and relative change of CA 15-3 (metformin vs placebo) were compared using Wilcoxon rank and t tests. Regression models adjusted for baseline differences and assessed key interactions. All statistical tests were 2-sided. Results: Mean (SD) age was 52.4 (10.0) years. The majority of patients had T2/3, node-positive, hormone receptor-positive, HER2-negative breast cancer treated with (neo)adjuvant chemotherapy and hormone therapy. Mean (SD) baseline CA 15-3 was 17.7 (7.6) and 18.0 (8.1 U/mL). At 6 months, CA 15-3 was statistically significantly reduced in metformin vs placebo arms (absolute geometric mean reduction in CA 15-3 = 7.7% vs 2.0%, P < .001; relative metformin: placebo level of CA 15-3 [adjusted for age, baseline body mass index, and baseline CA 15-3] = 0.94, 95% confidence interval = 0.92 to 0.96). This reduction was independent of tumor characteristics, perioperative systemic therapy, baseline body mass index, insulin, and the single nucleotide polymorphism status (all Ps > .11). Conclusions: Our observation that metformin reduces CA 15-3 by approximately 6% was corroborated in a large placebo-controlled randomized trial. The clinical implications of this reduction in CA 15-3 will be explored in upcoming efficacy analyses of breast cancer outcomes in MA.32.

Effect of metformin versus placebo on metabolic factors in the MA.32 randomized breast cancer trial.

Metformin may exert anticancer effects through indirect (mediated by metabolic changes) or direct mechanisms. The goal was to examine metformin impact on metabolic factors in non-diabetic subjects and determine whether this impact varies by baseline BMI, insulin, and rs11212617 SNP in CCTG MA.32, a double-blind placebo-controlled randomized adjuvant breast cancer (BC) trial. 3649 subjects with T1-3, N0-3, M0 BC were randomized; pretreatment and 6-month on-treatment fasting plasma was centrally assayed for insulin, leptin, highly sensitive C-reactive protein (hsCRP). Glucose was measured locally and homeostasis model assessment (HOMA) calculated. Genomic DNA was analyzed for the rs11212617 SNP. Absolute and relative change of metabolic factors (metformin versus placebo) were compared using Wilcoxon rank and t-tests. Regression models were adjusted for baseline differences and assessed interactions with baseline BMI, insulin, and the SNP. Mean age was 52 years. The majority had T2/3, node positive, hormone receptor positive, HER2 negative BC treated with (neo)adjuvant chemotherapy and hormone therapy. Median baseline body mass index (BMI) was 27.4 kg/m2 (metformin) and 27.3 kg/m2 (placebo). Median weight change was -1.4 kg (metformin) vs +0.5 kg (placebo). Significant improvements were seen in all metabolic factors, with 6 month standardized ratios (metformin/placebo) of 0.85 (insulin), 0.83 (HOMA), 0.80 (leptin), and 0.84 (hsCRP), with no qualitative interactions with baseline BMI or insulin. Changes did not differ by rs11212617 allele. Metformin (vs placebo) led to significant improvements in weight and metabolic factors; these changes did not differ by rs11212617 allele status.

Efficacy of Checkpoint Inhibitors in Neuroendocrine Neoplasms: Mayo Clinic Experience.

OBJECTIVES: Checkpoint inhibitors (CPIs) for low- and intermediate-grade neuroendocrine tumors (NETs) have been associated with limited efficacy; recent studies suggest CPIs may represent promising treatment for high-grade neuroendocrine neoplasms (NENs). METHODS: We examined 57 patients with NENs who were treated with CPIs to determine if NETs and neuroendocrine carcinomas (NECs) respond to immunotherapy. RESULTS: Patients with poorly differentiated NECs on CPI monotherapy had an objective response rate (ORR) of 0% and median progression-free survival (PFS) of 2.1 months (95% confidence interval [CI], 0.5-4.6). Patients with poorly differentiated NECs on dual CPI therapy had an ORR of 13% and PFS of 3.5 months (95% CI, 1.4-not reached [NR]). Patients with poorly differentiated NECs on CPI and cytotoxic therapy had an ORR of 36% with PFS of 4.2 months (95% CI, 1.6-NR). Well-differentiated grade 1 and 2 NETs on CPI monotherapy had an ORR of 25% with PFS NR. Well-differentiated grade 3 NETs had 0% ORR with a PFS of 2.9 months (95% CI, 1.4-4.2) on CPI monotherapy. CONCLUSIONS: Checkpoint inhibitor therapy shows limited activity in patients with NENs. Future studies should identify biomarkers that can help identify patients who are likely responders to immunotherapy.

Neuroendocrine Carcinoma of the Anus and Rectum: Patient Characteristics and Treatment Options.

INTRODUCTION: Anorectal neuroendocrine carcinomas (NECs) are uncommon malignancies with poor prognosis. Consensus guidelines exist for treating extrapulmonary NEC. However, limited data is available to guide treatment for anorectal NEC. In this study, we sought to review the clinical characteristics and outcomes of patients with NEC of the rectum and/or anus at Mayo Clinic. PATIENTS AND METHODS: This is a retrospective study of all patients with the diagnosis of NEC of the anus and/or rectum treated across Mayo Clinic sites since 2000. Baseline patient characteristics, tumor pathology, imaging profiles, treatment strategies utilized, and survival outcomes were analyzed. Kaplan-Meier analysis was used with a significance level of P < .05. RESULTS: The study included a total of 38 patients with primary NEC of the anus and/or rectum. The median age at diagnosis was 55.5 years. The median follow-up was 18.8 months. Fifteen patients had locoregional disease (LRD) at diagnosis. The remaining 23 had metastatic disease. Overall survival was significantly shorter in patients with LRD compared with those with metastatic disease at diagnosis (18.1 vs. 13.8 months; P = .039). The majority (n = 11) of patients with LRD were treated with concurrent chemoradiation therapy, and 10 underwent surgical resection of the primary tumor. The majority (13/15) of patients with LRD progressed, with the majority (11/15) of progressions being distant. The median progression-free survival for patients with LRD was 5.7 months (1-year progression-free survival, 26.7%). CONCLUSION: Anorectal NEC is an aggressive malignancy with poor prognosis requiring multidisciplinary discussion. In addition, the systemic nature of anorectal NEC with distant recurrences in LRD and poor outcomes in metastatic disease emphasizes the need to further develop better systemic treatment options that can potentially improve outcomes in NEC.