title: WCRF/AICR recommendation adherence and breast cancer incidence among postmenopausal women with and without non-modifiable risk factors.
abstract: Taller height, family history of breast cancer, greater number of years of potential fertility and nulliparity are established non-modifiable risk factors for postmenopausal breast cancer. Greater adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) diet, physical activity and body weight recommendations has previously been shown to be associated with lower breast cancer risk. However, no prior studies have evaluated whether women with non-modifiable risk factors receive similar benefits from recommendation adherence compared to women without these risk factors. In the Iowa Women's Health Study prospective cohort, we investigated whether associations of WCRF/AICR recommendation adherence differed by the presence/absence of non-modifiable breast cancer risk factors. Baseline (1986) questionnaire data from 36,626 postmenopausal women were used to create adherence scores for the WCRF/AICR recommendations (maximum score = 8.0). Overall and single recommendation adherence in relation to breast cancer risk (n = 3,189 cases) across levels of non-modifiable risk factors were evaluated using proportional hazards regression. Mean adherence score was 5.0 points (range: 0.5-8.0). Higher adherence scores (score ≥ 6.0 vs. ≤ 3.5, HR = 0.76, 95% CI = 0.67-0.87), and adherence to the individual recommendations for body weight and alcohol intake were associated with a lower breast cancer incidence. While not statistically significant among women with more non-modifiable risk factors (score ≥ 6.0 vs. ≤ 3.5, HR = 0.76, 95% CI = 0.36-1.63), hazard ratios were comparable to women with the no non-modifiable risk factors (score ≥ 6.0 vs. ≤ 3.5, HR = 0.74, 95% CI = 0.49-0.93) (p-interaction = 0.57). WCRF/AICR recommendation adherence is associated with lower breast cancer risk, regardless of non-modifiable risk factor status.
authors.affiliation: Office of Minority Health and Health Disparities Research, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC.
authors.forename: Sarah J O
authors.initials: SJ
authors.lastname: Nomura
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD.
authors.forename: Maki
authors.initials: M
authors.lastname: Inoue-Choi
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota-School of Public Health, Minneapolis, MN.|Prevention and Etiology Program, Masonic Cancer Center, Minneapolis, MN.
authors.forename: DeAnn
authors.initials: D
authors.lastname: Lazovich
authors.affiliation: Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, George Washington University, Washington, DC.
authors.forename: Kim
authors.initials: K
authors.lastname: Robien
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007484:Iowa; D008019:Life Style; D008875:Middle Aged; D017698:Postmenopause; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016387:Women's Health
keywords: body weight; breast cancer; cancer prevention; diet; physical activity