Calcium, Vitamin D, Dairy Products, and Mortality Among Colorectal Cancer Survivors: The Cancer Prevention Study-II Nutrition Cohort

Yang B, McCullough ML, Gapstur SM, et al

J Clin Oncol. 2014;32:2335-2343

Study Summary

Diet and lifestyle changes may play an important role in cancer pathogenesis. Yang and fellow American Cancer Society investigators analyzed the role of calcium, vitamin D, and dairy product intake before and after diagnosis of nonmetastatic colorectal cancer. The study population comprised 2284 participants in a prospective cohort study.

In multivariate analysis, post-diagnosis total calcium intake was inversely associated with all-cause mortality (relative risk [RR] for those in the highest relative to the lowest quartiles, 0.72; 95% confidence interval [CI], 0.53-0.98; Ptrend = .02). An inverse association with all-cause mortality was also observed for postdiagnosis milk intake (RR, 0.72; 95% CI, 0.55-0.94; Ptrend = .02), but not for vitamin D intake. Prediagnosis intakes were not associated with mortality.

Viewpoint

Diet and modifiable lifestyle factors are important issues for survivors of localized colorectal cancer. Unfortunately, randomized trials in this setting are difficult to conduct, require prolonged follow-up, and may not be able to control for all lifestyle factors. Therefore, data from well-conducted prospective cohort studies may be good enough to make recommendations to patients.

This study suggests that increased milk and calcium intake is associated with improved outcomes. Limitations include the primarily white study population with known higher rates of lactase persistence; in addition, the lack of association with vitamin D intake is inconsistent with prior reports.[1] Increased milk and calcium intake, along with reduced red meat intake and regular exercise, can be discussion points for survivors of colorectal cancer interested in modifiable lifestyle risk factors.

Abstract