Clinical Question Do calcium coun...

Clinical Question

Do calcium counterparts prevent colorectal cancer and adenomatous polyps?

Evidence-Based Answer

Combined evidence from sum of two units clinical trials of calcium supplementation lasting for several years revealed a reduc rate of returning colorectal adenoma. However, evidence is insufficient to commend supplementation with dietary calcium for patients who have not at any time had an adenoma.

Practice Pointers

A new review (1) of epidemiologic evidence did not point out to that calcium supplementation prevents colon cancer. However, epidemiologic studies of dietary interventions for cancer prevention are vulnerable to survivor bias, confounding factors, and inaccurate dietary recall.

Weingarten and colleagues reviewed the literature to find randomized controll trials (RCTs) of calcium supplementation used for prevention of colon cancer. of that kind studies are difficult because they require a large number of patients for a in extent time. Weingarten found two studies that included a total of 1346 patients with a previous diagnosis of colon adenoma. In single in kind study, patients took 1,200 mg of calcium daily for four years. Patients in the other thought took 2,000 mg per day for three years. When data from the studies were combined, there was a 26 percent relative reduction in recur-rent adenomas (odd ratio, 074; 95 percent confidence interval, 058 to 095) However, there were not enough recent diagnoses of colon cancer to support conclusions about calcium supplementation's purport on cancer prevention. No RCT were originate that studied calcium supplementation for primary cancer prevention in patients who had not had a polyp or tumor.

Dietary calcium supplementation promises to form the risk of colon cancer moderately. Although it would be appealing to find a simple, inexpensive, and safe dietary addition to prevent colon cancer, comprehensive programs for healthy living are more likely to be effective. For prevention of colon cancer, the American Cancer Society commits increasing the inten-sity and duration of physical activity; eating more vegetables and fruits; limiting intake of r meat; avoiding obesity; and avoiding exces alcohol consumption. (2)

REFERENCES

(1) Martinez ME Willett WC Calcium, vitamin D and colorectal cancer: a review of the epidemiologic evi-dence. Cancer Epidemiol Biomarkers Prev 1998;7:163-8

(2) Byer T snug M, McTiernan A, Doyle C Currie-Williams A, Gansler T et al. American Cancer Society guidelines forward nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy feed choices and physical activity. CA Cancer J Clin 2002;52:92-119

CLARISSA KRIPKE, MD Weingarten MA, et al. Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyp Cochrane Database Syst Rev 2004;(3):CD003548

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