1. Body fatness and breast cancer risk in relation to phosphorylated mTOR expression in a sample of predominately Black women
- Author
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Rochelle Payne Ondracek, Christine B. Ambrosone, Chi Chen Hong, Thaer Khoury, Warren Davis, Susmita Datta, Tongguang Cheng, Wiam Bshara, Angela Omilian, Song Yao, Song Liu, Elisa V. Bandera, and Weizhou Zhang
- Subjects
Adult ,0301 basic medicine ,Oncology ,medicine.medical_specialty ,Population ,Breast Neoplasms ,Body Mass Index ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Internal medicine ,Body fatness ,Odds Ratio ,medicine ,Body Size ,Humans ,Obesity ,Phosphorylation ,Prospective cohort study ,education ,RC254-282 ,Adiposity ,education.field_of_study ,African American/Black women ,New Jersey ,business.industry ,TOR Serine-Threonine Kinases ,Case-control study ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Odds ratio ,Middle Aged ,medicine.disease ,Black or African American ,030104 developmental biology ,Case-Control Studies ,030220 oncology & carcinogenesis ,Female ,New York City ,business ,Mechanistic target of rapamycin ,Body mass index ,Bioelectrical impedance analysis ,Research Article - Abstract
Background The mechanistic target of rapamycin (mTOR) pathway promoted by positive energy imbalance and insulin-like growth factors can be a mechanism by which obesity influences breast cancer risk. We evaluated the associations of body fatness with the risk of breast cancer varied with phosphorylated (p)-mTOR protein expression, an indication of the pathway activation. Methods Women with newly diagnosed breast cancer (n = 715; 574 [80%] Black and 141 [20%] White) and non-cancer controls (n = 1983; 1280 [64%] Black and 713 [36%] White) were selected from the Women’s Circle of Health Study. Surgical tumor samples among the cases were immunostained for p-mTOR (Ser2448) and classified as p-mTOR-overexpressed, if the expression level ≥ 75th percentile, or p-mTOR-negative/low otherwise. Anthropometrics were measured by trained staff, and body composition was determined by bioelectrical impedance analysis. Odds ratios (ORs) of p-mTOR-overexpressed tumors and p-mTOR-negative/low tumors compared to controls were estimated using polytomous logistic regression. The differences in the associations by the p-mTOR expression status were assessed by tests for heterogeneity. Results Cases with p-mTOR-overexpressed tumors, but not cases with p-mTOR-negative/low tumors, compared to controls were more likely to have higher body mass index (BMI), percent body fat, and fat mass index (P-heterogeneity P-heterogeneity = 0.27 and 0.48, respectively). Conclusions Our findings suggest that in this population composed of predominately Black women, body fatness is associated with breast cancer differently for p-mTOR overexpression and p-mTOR negative/low expression. Whether mTOR plays a role in the obesity and breast cancer association warrants confirmation by prospective studies.
- Published
- 2021