Cifu G, et al. – Given that breast cancer is the most common cancer in women and many lifestyle factors have been associated with an increased risk of breast cancer incidence and mortality, researchers theorized that an index-based approach to analyzing adherence to American Cancer Society (ACS) guidelines as a whole may better explain associations between lifestyle variables and breast cancer incidence and mortality. Thus, they developed an index based on ACS-specific guidelines, including body mass index, physical activity, alcohol intake, tobacco use, daily time spent watching television, and select dietary habits. They used Cox proportional hazards regression to model the association between lifestyle index and primary breast cancer and breast cancer-specific mortality in the National Institutes of Health- American Association of Retired Persons (NIH-AARP) cohort. The investigators found that a healthier pre-diagnosis lifestyle was associated with a decreased risk of breast cancer and all-cause mortality in the NIH-AARP cohort.