Abstract B72: Obesity and breast cancer in African-American and Latina Women: A hospital-based comparison study

Abstract

Abstract Background: Obesity is considered a major risk factor for cancers, in particular breast cancer. This phenomenon is becoming a major public health concern. Hence, modifying life-styles that could reduce obesity offers the potential for prevention as well as improvement of outcomes from cancer. Though the exact mechanisms of the effects of obesity on the etiology and progression of breast cancer are yet unclear, some studies suggest that increased body fat is associated with increased levels of estrogen and growth factors such as insulin-like growth factor 1 (IGF-I) which promote tumorogenesis. The effects of obesity and breast cancer in African-American women and Latina women have been explored in a limited number of studies. The aim of this study is to investigate the association of obesity with breast cancer in our cohort of minority women. Methods: Our study is a hospital based comparative study of over 300 African-American and Latina women in South Los Angeles who visited the Mammography Screening unit and/or the Hematology Oncology Clinic at Martin Luther King Ambulatory Care Center (MACC, formerly known as King-Drew Medical Center). Information regarding BMI and clinical and lifestyle-factors were obtained by medical record abstraction. Logistic regression with multivariate analysis was used to determine the association between obesity, breast cancer, and additional variables. We also examined the effect of comorbidity on breast cancer. Results: Our results show a significant association of breast cancer with obesity. Women with breast cancer were more likely to be obese (BMI>30) than women without breast cancer (OR =1.33; P-value <0.01). Furthermore, upon stratification by menopausal status, there was a significant association of premenopausal cases with obesity (OR =1.36; P-value <0.01) but not with postmenopausal cases with obesity (P-value =0.08). In addition, when stratifying by the self-identified ethnicity of the subject, our study found that an association of obesity with breast cancer was significant only in African-American women (OR =1.97; P-value <0.01), especially premenopausal African American women (OR =2.02; P-value <0.01). We did not find an association of obesity with breast cancer in Latina women (OR =1.21; P-value =0.09). Next, we investigated whether obesity was associated with comorbidity-which may contribute to poorer outcome. We found an association of obesity with comorbidity, specifically with hypertension, after adjusting for case/control and ethnicity (OR = 1.90; P-value = 0.04). Comorbidity alone was also significantly associated with breast cancer, independent of obesity. Conclusion: Our data suggest an association of obesity with breast cancer, especially in premenopausal women and most significantly in the pre-menopausal African-American cohort. In addition, we show that hypertension as comorbidity plays a significant role in for breast cancer. Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):B72.