Metformin has been associated with lower breast cancer (BC) risk and improved outcomes in observational studies. Multiple biologic mechanisms have been proposed, including a recent report of altered sex hormones. We evaluated the effect of metformin on sex hormones in MA.32, a phase III trial of nondiabetic BC subjects who were randomly assigned to metformin or placebo. We studied the subgroup of postmenopausal hormone receptor-negative BC subjects not receiving endocrine treatment who provided fasting blood at baseline and at 6 months after being randomly assigned. Sex hormone-binding globulin, bioavailable testosterone, and estradiol levels were assayed using electrochemiluminescence immunoassay. Change from baseline to 6 months between study arms was compared using Wilcoxon sum rank tests and regression models. 312 women were eligible (141 metformin vs 171 placebo); the majority of subjects in each arm had T1/2, N0, HER2-negative BC and had received (neo)adjuvant chemotherapy. Mean age was 58.1 (SD=6.9) vs 57.5 (SD=7.9) years, mean body mass index (BMI) was 27.3 (SD=5.5) vs 28.9 (SD=6.4) kg/m² for metformin vs placebo, respectively. Median estradiol decreased between baseline and 6 months on metformin vs placebo (−5.7 vs 0 pmol/L; P < .001) in univariable analysis and after controlling for baseline BMI and BMI change (P < .001). There was no change in sex hormone-binding globulin or bioavailable testosterone. Metformin lowered estradiol levels, independent of BMI. This observation suggests a new metformin effect that has potential relevance to estrogen sensitive cancers.

Background: In 2012, the American Society for Clinical Oncology (ASCO) identified five key opportunities in oncology to improve patient care, recommending against imaging tests for the staging of patients with early breast cancer (EBC) at low risk for metastases. Similarly, the European Society of Medical Oncology (ESMO) guideline does not support radiological staging in asymptomatic EBC (aEBC). The purpose of this study was to assess local practice and outcomes of staging investigations (SIs) in aEBC at the Cancer Centre of Southeastern Ontario (CCSEO). Methods: A retrospective electronic and paper chart review was undertaken to identify all aEBC patients treated at our institution between January 2012 and December 2014. Patients with pathological staging of T1-T2 and N0-1 with any receptor status were included. We collected patient demographics, treatment and pathologic tumor characteristics. The use and outcomes of initial and follow-up SIs were recorded. Data were analyzed to determine associations between the use of SIs and clinical characteristics (chi-square tests, independent samples t-tests and Mann–Whitney U tests). Results: From 2012 to 2014, 295 asymptomatic EBC patients were identified. The mean age was 64, 81% were postmenopausal and 76% had breast conserving surgery. Stage distribution was as follows: stage I 42%, stage IIA 37% and stage IIB 21%. Receptor status was as follows: ER+ 84%, HER2+ 13% and triple negative 12%. Adjuvant chemotherapy was received by 36%, Trastuzumab by 10% and endocrine therapy by 76% of patients. Baseline SIs were performed in 168 patients (57%) for a total of 332 tests. Overt metastatic disease was found in five patients (one bone scan and four CT scans). Seventy-one out of the 168 patients (42%) who received initial staging imaging underwent 138 follow-up imaging tests, none of which were diagnostic for metastases. Nine patients with suspicious CT findings underwent biopsies, of which four were malignant (one metastatic breast cancer and three new primaries). Factors significantly associated with SI were as follows: younger age (p = 0.001), premenopausal status (p = 0.01), T2 stage (p < 0.001), N1 stage (p < 0.001), HER2 positive (p < 0.001), triple negative status (p = 0.007) and use of adjuvant chemotherapy (p < 0.001). Conclusions: Over a 3-year period at our institution, more than 50% of aEBC patients underwent a total of 470 initial and follow-up staging tests, yielding a cancer diagnosis (metastatic breast cancer or second primary cancer) in four patients. We, therefore, conclude that routine-staging investigations in aEBC patients have low diagnostic value, supporting current guidelines that recommend against the routine use of SI in this population.

A cost–utility analysis was performed based on the Rethinking Clinical Trials (REaCT) bone-targeted agents (BTA) clinical trial that compared 12-weekly (once every 12 weeks) (n = 130) versus 4-weekly (once every 4 weeks) (n = 133) BTA dosing for metastatic breast and castration-resistant prostate (CRPC) cancer. Using a decision tree model, we calculated treatment and symptomatic skeletal event (SSE) costs as well as quality-adjusted life-years (QALYs) for each treatment option. Deterministic and probabilistic sensitivity analyses were performed to assess the robustness of the study findings. The total cost of BTA treatment in Canadian dollars (C$) and estimated QALYs was C$8965.03 and 0.605 QALY in the 4-weekly group versus C$5669.95 and 0.612 QALY in the 12-weekly group, respectively. De-escalation from 4-weekly to 12-weekly BTA reduces cost (C$3293.75) and improves QALYs by 0.008 unit, suggesting that 12-weekly BTA dominates 4-weekly BTA in breast and CRPC patients with bone metastases. Sensitivity analysis suggests high levels of uncertainty in the cost-effectiveness findings. De-escalation of bone-targeted agents is cost-effective from the Canadian public payer’s perspective.

We report a case of dermatomyositis in a 59-year old female with advanced non-small-cell lung cancer post one cycle of first-line pembrolizumab monotherapy. Her symptoms resolved with high-dose met...

Aplastic anemia is a rare but potentially serious complication of immune checkpoint inhibitor therapy. The authors present a case of pembrolizumab-induced aplastic anemia that was refractory to ste... Plain language summary Immune checkpoint inhibitors (ICIs) are a form of anticancer therapy that enlists the body's own immune system to fight cancer cells. Although remarkably effective against so...