Gene transcription signature of obesity in breast cancer. Homo sapiens

Obesity is thought to contribute to worse disease outcome in breast cancer as a result of increased levels of adipocyte-secreted endocrine factors, insulin, and insulin-like growth factors (IGFs) that accelerate tumor cell proliferation and impair treatment response. We examined the effects of patient obesity on primary breast tumor gene expression, by profiling transcription of a set of tumors for which the patients’ body mass index (BMI) was ascertained. Sample profiles were stratified according to patients’ obesity phenotype defined as normal (BMI 30). Widespread alterations in gene expression were evident in breast tumors from obese patients as compared to tumors from other patients, allowing us to define an obesity-associated cancer transcriptional signature of 662 genes. Keywords: two group comparison Overall design: Primary breast tumor specimens were obtained from patients. Study volunteers completed questionnaires used to define historically normal (BMI=30) patient categories according to established WHO criteria.