Mega-Dose Vitamins and Breast Cancer

In December 2002, M. L. Lesperance and colleagues published a study of patients with nonmetastatic breast cancer who had been treated with a course of beta-carotene, niacin, vitamin C, selenium, coenzyme Q10, and zinc at an alternative cancer clinic under the directorship of Abram Hoffer, MD, who also served as one of the authors of the article. Dr Hoffer obtained data from medical charts of his patients to provide a treatment group, which we will refer to as the orthomolecular medicine group. Lesperance and colleagues obtained a control group from the British Columbia Cancer Agency–Vancouver Island Centre (BCCA-VIC). The orthomolecular group consisted of female patients with unilateral breast cancer who had been prescribed a course of varying amounts of the supplements, and who had been followed for at least 2 months. They were advised to take the supplements whether or not they had radiation or chemotherapy. From a group of 271 breast cancer patients initially identified by Hoffer, a group of 90 was selected, made up of those with nonmetastatic unilateral breast cancer who had outcome records in the files of the BCCAVIC, were diagnosed between 1989 and 1998, were followed for at least 2 months, and began the supplementation within 180 days of diagnosis. Supplementation levels were as follows: most patients took approximately 25,000 IU daily of beta-carotene, over 1 g niacin, approximately 12 g of vitamin C daily, coenzyme Q10 (amount not given), between 1 and 750 mcg selenium, and approximately 50 mg zinc. Not all patients were prescribed the same supplementation levels. The control group (n = 180) was selected from 2360 women with nonmetastatic breast cancer referred to BCCA-VIC during the same time period. Two control patients were selected for each of the 90 supplement patients. Controls were matched on the basis of tumornode-metastasis stage; age (within 5 years); year of diagnosis (within 2 years); number of positive nodes for N1 patients; presence of lymphatic, vascular, or neural invasion; histopathology; estrogen receptor status; and whether systemic treatment (chemotherapy or hormonal therapy) was prescribed for the patient. Statistical methods used to compare the 2 groups included chi-square tests of homogeneity, Kaplan-Meier survival curves, log-rank tests, and Cox proportional hazards analysis. The 2 groups proved to be matched on most prognostic variables, with the exception that a larger number of the supplemented patients did not have radiation therapy after lumpectomy (16% of the supplemented vs 7% of the controls), whereas a larger percentage of the control patients had total mastectomy without radiation therapy. The general patterns of local treatment between the 2 groups were significantly different (P = .04). Results of statistical analysis indicated that there was no difference between the 2 groups in breast cancer– specific survival (BCSS) or disease-free survival (DFS) (P = .16 for BCSS and P = .07 for DFS). Survival of the supplemented group appeared somewhat lower than that of the control group; however, the sample size was not large enough to determine this difference reliably. The overall survival at 5 years was 72% for the supplemented group and 81% for the control group. This study had many good features. It provided a very tight control for a relatively large cohort of patients who sought alternative therapy soon after being diagnosed with cancer. Cases and controls both received local treatment (surgery and radiation therapy) at a single regional cancer center with established clinical practice guidelines. The authors also pointed out several problems with the study. Power calculations had been made on an estimate of a 25% to 30% increase in BCSS and DFS in the supplemented group over that of the control group. The resulting sample size, however, was too small to detect differences of the magnitude that were actually observed. The higher percentage of supplemented patients who did not receive radiation therapy after lumpectomy could have led to a higher rate of local, or perhaps systemic, recurrence. Whether patients in either group were taking other supplements was not known. Although Point-Counterpoint

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