Association of Body Composition with Odds of Breast Cancer by Molecular Subtype: Analysis of the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Nigerian Women (MEND) Study

BACKGROUND: The association between obesity and breast cancer (BC) has been extensively studied among US, European and Asian study populations, with often conflicting evidence. However, despite the increasing prevalence of obesity and associated conditions in Africa, the continent with the highest age-standardized BC mortality rate globally, few studies have evaluated this association, and none has examined in relation to molecular subtypes among African women. The current analysis examines the association between body composition, defined by body mass index (BMI), height, and weight, and BC by molecular subtype among African women. METHODS: We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) for the association between measures of body composition and BC and molecular subtypes among 419 histologically confirmed cases of BC and 286 healthy controls from the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Women of Nigerian Descent (MEND) case-control study. RESULTS: Higher BMI (aOR: 0.79; 95% CI: 0.67, 0.95) and weight (aOR: 0.83; 95% CI: 0.69, 0.98) were associated with reduced odds of BC in adjusted models, while height was associated with non-statistically significant increased odds of BC (aOR: 1.07, 95% CI: 0.90, 1.28). In pre/peri-menopausal, but not post-menopausal women, both higher BMI and weight were significantly associated with reduced odds of BC. Further, higher BMI was associated with reduced odds of Luminal A, Luminal B, and HER2-enriched BC among pre/peri-menopausal women, and reduced odds of triple-negative BC among post-menopausal women. CONCLUSIONS: Higher BMI and weight were associated with reduced odds of BC overall and by molecular subtype among West African women. Larger studies of women of African descent are needed to definitively characterize these associations and inform cancer prevention strategies

Projecting Survival in Papillary Thyroid Cancer: A Comparison of the Seventh and Eighth Editions of the American Joint Commission on Cancer/Union for International Cancer Control Staging Systems in Two Contemporary National Patient Cohorts

BackgroundThis study aims to compare the seventh and eighth editions of the American Joint Commission on Cancer/Union for International Cancer Control (AJCC/UICC) tumor, node, metastasis staging system for patients with papillary thyroid cancer (PTC) in two national patient cohorts.MethodsAdult PTC patients undergoing surgery were selected from the Surveillance, Epidemiology and End Results (SEER) program (2004-2012) and the National Cancer Database (2004-2012). Staging criteria for the seventh and eighth AJCC/UICC editions were applied separately to each cohort. Survival probabilities were estimated using the Kaplan-Meier method. Multivariable Cox proportional hazards models were used to estimate the association of stage with survival in both settings. The Akaike information criterion was used to assess model performance.ResultsAbout 23% of patients were downstaged from the seventh to the eighth edition in SEER, while 24% were downstaged in the National Cancer Database. Disease-specific survival (DSS) and overall survival (OS) were significantly related to stage at diagnosis when using both the seventh and eighth editions of the AJCC/UICC staging system (p < 0.001). Patients classified into higher stages (III and IV) in the eighth edition showed a worse prognosis than those classified into similar stages in the seventh edition. After adjustment, PTC stages as defined by both editions were significantly associated with DSS and OS. With respect to both DSS and OS, the eighth edition PTC model appeared to be a better fit to the data (smaller Akaike information criterion values) compared to the seventh edition.ConclusionBased on these large contemporary national cohorts, the eighth edition AJCC/UICC tumor, node, metastasis classification for PTC is superior to the seventh edition for predicting survival