The 2018 World Cancer Research Fund/American Institute for Cancer Research Score and Cancer Risk: A Longitudinal Analysis in the NIH-AARP Diet and Health Study.

ABSTRACT

BACKGROUND: We examined associations between adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Cancer Prevention Recommendations using the standardized 2018 WCRF/AICR Score and cancer risk among older U.S. adults. METHODS: Participants included 215,102 adults in the NIH-AARP Diet and Health Study followed between 2004 and 2011 (mean 7.0 person-years). Scores (range 0-7 points) were calculated from self-reported weight, physical activity, and diet and alcohol intake measures. Outcomes included 17 cancers reviewed by WCRF/AICR (cases male n = 11,066; female n = 8,865) and top three U.S. cancers in males (total n = 4,658; lung n = 2,211; prostate n = 920; colorectal n = 1,527) and females (total n = 5,957; lung n = 1,475; post-menopausal breast n = 3,546; colorectal n = 936). Cox proportional hazard ratios (HRs) were estimated for score and cancer risk associations, stratifying by sex and smoking status. RESULTS: Each one-point score increase was associated with 6% to 13% reduced cancer risk across combined outcomes, except for male never smokers' risk for top three cancers and male current smokers' risk for both combined cancer outcomes. Higher scores were associated with decreased lung cancer risk only among male former smokers (HR, 0.84; 95% CI, 0.79-0.89) and female current smokers (HR, 0.89; 95% CI, 0.82-0.96). Higher scores were associated with 7% to 19% decreased breast cancer risk across smoking strata and 10% to 14% decreased colorectal cancer risk among male and female never and former smokers. CONCLUSIONS: Greater recommendations adherence was associated with reduced cancer risk. IMPACT Findings emphasize the importance of considering combined contributions of multiple lifestyle factors for cancer prevention among older adults and the potential modifying role of smoking history.