Selenium supplements may increase skin cancer risk
found that selenium supplements not only did not reduce the risk of
recurrence for previous sufferers of nonmelanoma skin cancer but
may even increase the risk of certain forms of skin cancer.
Contrary to previous research findings, a new study in the US has found that selenium supplements not only did not reduce the risk of recurrence for previous sufferers of nonmelanoma skin cancer but may even increase the risk of certain forms of skin cancer.
The Nutritional Prevention of Cancer Trial was a double-blind, randomised, placebo-controlled clinical trial designed to test whether 200 micrograms daily of selenium as selenized yeast could prevent nonmelanoma skin cancer among 1312 patients from the Eastern United States who had previously had this disease.
Results from 1983 to 1993, showed no association between treatment and the incidence of basal and squamous cell carcinomas of the skin. However, this new report summarises the entire blinded treatment period, which ended on 31 January 1996. The scientists evaluated the association between treatment and time to first nonmelanoma skin cancer diagnosis and between treatment and time to multiple skin tumours overall and within subgroups, defined by baseline characteristics.
Although results through the entire blinded period continued to show that selenium supplementation was not statistically significantly associated with the risk of basal cell carcinoma, the researchers reported a statistically significant association between selenium supplementation and an elevated risk of squamous cell carcinoma and of total nonmelanoma skin cancer.
'The results from the trial conducted among individuals at high risk of nonmelanoma skin cancer continue to demonstrate that selenium supplementation is ineffective at preventing basal cell carcinoma and that it increases the risk of squamous cell carcinoma and total nonmelanoma skin cancer,' concluded the resarchers.
Full details of the research can be found in the October issue of the Journal of the National Cancer Institute . Correspondence should be addressed to James R. Marshall at the Roswell Park Cancer Institute in New York.
