Is adherence to diet, physical activity, and body weight cancer prevention recommendations associated with colorectal cancer incidence in African American women?

Abstract

Purpose The purpose of this study was to evaluate whether adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations was associated with colorectal cancer incidence in the Black Women's Health Study (BWHS). Methods In this ongoing prospective cohort of African American women (analytic cohort N=49,103), 354 incident colorectal cancers were diagnosed between baseline (1995) and 2011. Adherence scores for seven WCRF/AICR recommendations (adherent=1 point, non-adherent level 1=0.5 points, non-adherent level 2=0 points) were created using questionnaire data and summed to an overall adherence score (maximum=7). Recommendation adherence and colorectal cancer incidence were evaluated using baseline and time-varying data in Cox regression models. Results At baseline, 8.5% of women adhered >4 recommendations. In time-varying analyses, the HR was 0.98 (95% CI: 0.84-1.15) per 0.5 point higher score and 0.51 (95% CI: 0.23-1.10) for adherence to >4 compared to <3 recommendations. Adherence to individual recommendations was not associated with colorectal cancer risk. Results were similar in models that considered baseline exposures only. Conclusions Adherence to cancer prevention recommendations was low and not associated with colorectal cancer risk among women in the BWHS. Research in diverse populations is essential to evaluate the validity of existing recommendations, and assess whether there are alternative recommendations that are more beneficial for cancer prevention in specific populations.

Dietary Patterns and Colorectal Cancer Risk: a Review of 17 Years of Evidence (2000–2016)

“…Corresponding results in women were 26% to 55% lower risk and 39% to 59% lower risk in men [39]**. Nomura et al and Makarem et al also calculated recommendation adherence scores in smaller cohort studies but found no association with colorectal cancer risk [40, 41]. None of the four studies examined risk by anatomic location of the cancer.…”

Association between meeting the WCRF/AICR cancer prevention recommendations and colorectal cancer incidence: results from the VITAL cohort

“…[10] In this study they created a three-level adherence score with low adherence women meeting <3 recommendations and high adherence women meeting >4 recommendations. Similar to Romaguera, the large low-adherence category of 0–2.5 recommendations likely limited the ability to detect associations between the high and low adherence and CRC risk.…”

“…[1] Meeting these recommendations has been associated with several outcomes, including lower total and site-specific cancer incidence [2–5] and all-cause and cancer mortality;[6–9] however, previous research into the association between meeting the WCRF/AICR and colorectal cancer (CRC) risk is limited,[2, 10] and has not examined whether observed associations differ by sex. Previous work has also not examined the associations between individual recommendations and CRC risk.…”

Mediating effects of cancer risk factors on the association between race and cancer incidence: analysis of the NIH-AARP Diet and Health Study

“…Very few studies have examined these associations among Blacks. In studies conducted in the Black Women’s Health Study only 8.5% of women met at least 4 of the guidelines, and although no association was observed between increased adherence and colorectal cancer incidence [10], increasing adherence was also associated with reduced breast cancer incidence [7]. Another study reported that BMI mediated nearly 18% of the association between Black race and breast cancer mortality, though non-significant [34].…”