Epidemiologic studies have shown that diabetics receiving the biguanide metformin, as compared to sulfonylureas or insulin, have a lower incidence of breast cancer. Metformin increases levels of activated AMPK and decreases circulating IGF-1; encouraging its potential use in both cancer prevention and therapeutic settings. In anticipation of clinical trials in non-diabetic women, the efficacy of metformin in non-diabetic rat and mouse mammary cancer models was evaluated. Metformin was administered by gavage or in the diet, at a human equivalent dose, in standard mammary cancer models: (1) methylnitrosourea (MNU)-induced ER+ mammary cancers in rats, and (2) MMTV-Neu/P53KO ER- mammary cancers in mice. In the MNU rat model, metformin dosing (150 or 50 mg/Kg BW/day, by gavage) was ineffective in decreasing mammary cancer multiplicity, latency, or weight. Pharmacokinetic studies of metformin (150 mg/kg BW/day, by gavage) yielded plasma levels (Cmax and AUC) higher than humans taking 1.5 g/day. In rats bearing small palpable mammary cancers, short-term metformin (150 mg/kg BW/day) treatment increased levels of phospho-AMPK and phospho-p53 (Ser20) but failed to reduce Ki67 labeling or expression of proliferation-related genes. In the mouse model, dietary metformin (1500 mg/kg diet) did not alter final cancer incidence, multiplicity, or weight. Metformin did not prevent mammary carcinogenesis in two mammary cancer models; raising questions about metformin efficacy in breast cancer in non-diabetic populations.

A consensus conference including thirty experts was held in April, 2007, to discuss risk factors for breast cancer and their management. Four categories of risk were outlined, from breast cancer "average" through "very high" risk, the latter including individuals with high penetrance BRCA1 / 2 gene mutations. Guidelines for management of patients in each of these categories were discussed, with the major portion of the conference being devoted to individuals with BRCA1 / 2 mutations. Prevalence of these mutations in the general populations was estimated to be 1 in 250-500 individuals, with an increased prevalence in Ashkenazic Jews and other founder groups. Risk reduction strategies for these individuals include surveillance, with or without chemoprevention drugs, or surgical procedures to remove the organs at risk, i.e., bilateral mastectomy and / or bilateral salpingo-oophorectomy. These risk reduction strategies were evaluated fully, and recommendations were made for the care of patients in each of the risk categories. These guidelines for patient care were approved by the entire group of experts.

Purpose To evaluate whether differences in PAM50 breast cancer (BC) intrinsic (Luminal A, Luminal B, Basal-like, and HER2-enriched) subtype help explain the Black-White BC survival disparity. Methods Utilizing a stratified case-cohort design, this study included 1,635 women from the Pathways and Life After Cancer Epidemiology cohorts, selecting women with tumors based upon IHC classification, recurrences, and deaths. One millimeter punches were obtained from tumor tissue, and expression of the PAM50 genes for molecular subtype was determined by RT-qPCR of extracted RNA. Cox proportional hazards models were used to analyze associations between race and BC outcomes, adjusted for PAM50 BC subtype. All tests of statistical significance were two-sided. Results Black women had a higher prevalence of the Basal-like BC subtype. Adjusted for potential confounding variables and disease characteristics at diagnosis, Black women had higher risks of recurrence (HR=1.65, 95% CI: 1.06–2.57) and breast-cancer-specific mortality (HR=1.71, 95% CI: 1.02–2.86) than White women, but adjusting further for subtype did not attenuate survival disparities. By contrast, Hispanic women had a lower risk of recurrence (HR=0.54, 95% CI: 0.30–0.96) than Whites. Among those with the Basal-like subtype, Black women had a similar recurrence risk as women in other race groups but a higher recurrence risk for all other subtypes. Hispanic women had a lower recurrence risk within each subtype, though associations were not significant given limited power. Conclusions Although Black women had a higher risk of the Basal-like subtype, which has poor prognosis, this did not explain the Black-White breast cancer survival disparity.

s125 most commonly adopted strategy to overcome lack of data availability, especially in the private healthcare setting, in which data are scarcer. Therefore, the aim of this study is to describe costs of cancer treatment and supportive care infusion of drugs used in breast cancer treatment in a cancer clinic of the private healthcare setting. Methods: We reviewed the claims of cancer treatment and supportive care infusions in breast cancer patients treated in UNICA clinic (private clinic from São Paulo, Brazil) from 2014-2018. After identifying breast cancer patients, we descriptively evaluated infusions per drug. Data were summarized by median (minimum-maximum).

IntroductionWe hypothesized improved inter-laboratory comparability of estrogen receptor (ER) and progesterone receptor (PgR) across different assay methodologies with adjunctive statistical standardization, akin to bone mineral density (BMD) z-scores. We examined statistical standardization in MA.12, a placebo-controlled pre-menopausal trial of adjuvant tamoxifen with locally assessed hormone receptor +/- tumours, and in a cohort of post-menopausal British Columbia (BC) tamoxifen-treated patients.MethodsER and PgR were centrally assessed for both patient groups with real time quantitative reverse transcription polymerase chain reaction (qPCR) and immunohistochemistry (IHC). Effects on disease-free survival (DFS) were investigated separately for 345 MA.12 and 673 BC patients who had both qPCR and IHC assessments. Comparisons utilized continuous laboratory units and statistically standardized z-scores. Univariate categorization of ER/PgR was by number of standard deviations (SD) above or below the mean (z-score ≥1.0 SD below mean; z-score <1.0 SD below mean; z-score ≤1.0 SD above mean; z-score >1.0 SD above mean). Exploratory multivariate examinations utilized step-wise Cox regression.ResultsMedian follow-up for MA.12 was 9.7 years; for BC patients, 11.8 years. For MA.12, 101 of 345 (29%) patients were IHC ER-PgR-. ER was not univariately associated with DFS (qPCR, P = 0.19; IHC, P = 0.08), while PgR was (qPCR, P = 0.09; IHC, P = 0.04). For BC patients, neither receptor was univariately associated with DFS: for ER, PCR, P = 0.36, IHC, P = 0.24; while for PgR, qPCR, P = 0.17, IHC, P = 0.31. Multivariately, MA.12 patients randomized to tamoxifen had significantly better DFS (P = 0.002 to 0.005) than placebo. Meanwhile, jointly ER and PgR were not associated with DFS whether assessed by qPCR or by IHC in all patients, or in the subgroup of patients with IHC positive stain, for pooled or separate treatment arms. Different results by type of continuous unit supported the concept of ER level being relevant for medical decision-making. For postmenopausal BC tamoxifen patients, higher qPCR PgR was weakly associated with better DFS (P = 0.06).ConclusionsMA.12 pre-menopausal patients in a placebo-controlled tamoxifen trial had similar multivariate prognostic effects with statistically standardized hormone receptors when tumours were assayed by qPCR or IHC, for hormone receptor +/- and + tumours. The BC post-menopausal tamoxifen cohort did not exhibit a significant prognostic association of ER or PgR with DFS. Adjunctive statistical standardization is currently under investigation in other NCIC CTG endocrine trials.