Nutrition and physical activity cancer prevention guidelines, cancer risk, and mortality in the women's health initiative

Abstract

Healthy lifestyle behaviors are recommended to reduce cancer risk and overall mortality. Adherence to cancer-preventive health behaviors and subsequent cancer risk has not been evaluated in a diverse sample of postmenopausal women. We examined the association between the American Cancer Society (ACS) Nutrition and Physical Activity Cancer Prevention Guidelines score and risk of incident cancer, cancer-specific mortality, and all-cause mortality in 65,838 postmenopausal women enrolled in the Women's Health Initiative Observational Study. ACS guidelines scores (0-8 points) were determined from a combined measure of diet, physical activity, body mass index (current and at age 18 years), and alcohol consumption. After a mean follow-up of 12.6 years, 8,632 incident cancers and 2,356 cancer deaths were identified. The highest ACS guidelines scores compared with the lowest were associated with a 17% lower risk of any cancer [HR, 0.83; 95% confidence interval (CI), 0.75-0.92], 22% lower risk of breast cancer (HR, 0.78; 95% CI, 0.67-0.92), 52% lower risk of colorectal cancer (HR, 0.48; 95% CI, 0.32-0.73), 27% lower risk of all-cause mortality, and 20% lower risk of cancer-specific mortality (HR, 0.80; 95% CI, 0.71-0.90). Associations with lower cancer incidence and mortality were generally strongest among Asian, black, and Hispanic women and weakest among non-Hispanic whites. Behaviors concordant with Nutrition and Physical Activity Cancer Prevention Guidelines were associated with lower risk of total, breast, and colorectal cancers and lower cancer-specific mortality in postmenopausal women.

Figure 1

Associations between ACS cancer prevention guidelines score and (A) any incident cancer, (B) all-cause mortality, and (C) cancer-specific mortality. HRs were calculated with the lowest scores (0–3) as the reference group (HR = 1.0), stratified by race/ethnicity, and adjusted for the following: age (continuous), education (≤high school, some college, ≥college), smoking pack-years (never smoking, <5, 5–19, 20+), NSAID use at baseline (yes, no), aspirin use at baseline (yes, no), unopposed estrogen use (never, former, current), estrogen + progestin use (never, former, current), multivitamin use at baseline (yes, no), total energy intake (continuous), parous (yes, no, unknown), mammogram (ever, never), colonoscopy/sigmoidoscopy (ever, never), family history (mother/father, full-blooded sister/brother, daughter/son, grandmother) of cancer (yes, no, unknown), and having a current healthcare provider (yes, no). Vertical bars represent 95% CIs. Horizontal dashed lines represent the null HR of 1.0. Likelihood ratio test for interaction between race/ethnicity and ACS guidelines score (continuous) on each outcome: any incident cancer, P = 0.050; allcause mortality, P = 0.116; and cancer-specific mortality, P = 0.555.