The Associations Of Healthy Lifestyle Index With Breast Cancer Incidence And Mortality In A Population-Based Study

Abstract

\n Purpose: To investigate how a healthy lifestyle index (HLI) is associated with breast cancer risk and survival in a population-based breast cancer study.Methods: The study included 1,319 breast cancer cases and 1,310 controls from the population-based Long Island Breast Cancer Study Project, and its follow-up study of mortality. We determined vital status using the National Death Index (521 deaths, 210 from breast cancer; median follow-up 214.5 months). A healthy lifestyle index (HLI) score, was generated from information on body fatness, physical activity, intake of plant and animal foods, alcohol consumption, breastfeeding and smoking, with higher values representing engagement in healthier behaviors. Multivariable logistic and Cox regression were used to estimate breast cancer odds ratios (ORs) mortality hazards ratios (HRs), respectively.Results: Compared to women in the low HLI tertile, women in the intermediate (OR=0.78, 95%CI=0.65-0.94) and high (OR=0.68, 95%CI=0.56-0.83) tertiles had a decreased odds of breast cancer, and a one-point increase in HLI score was associated a reduction in breast cancer risk (OR=0.85, 95%CI=0.79–0.92). Women in the intermediate (HR=0.75, 95%CI=0.61-0.91) and high (HR=0.74, 95%CI=0.60-0.92) tertiles had a decreased rate of all-cause mortality, and a one-point increase in HLI score was associated with a reduction in all-cause mortality (HR=0.83, 95%CI =0.76-0.91). These associations were significant among postmenopausal.Conclusion: A healthy lifestyle may be beneficial in reducing breast cancer risk and improving overall survival after breast cancer diagnosis, especially among postmenopausal women.