In JAMA this week, researchers from across the US and Canada present results from a study of the long-term effects of vitamin E and selenium on the risk of prostate cancer in healthy men. A previous study showed neither selenium of vitamin E supplements reduced prostate cancer risk, but that study did show a statistically non-significant increase in prostate cancer risk with vitamin E use. To determine the long-term effects for this study, the researchers analyzed data from 34,887 men who were randomly assigned to receive selenium, vitamin E, both supplements, or a placebo. The team found that compared with the placebo group, in which 529 men developed prostate cancer, 620 men in the vitamin E group developed the disease, as did 575 in the selenium group, and 555 in the combination group. "The absolute increase in risk of prostate cancer per 1000 person-years was 1.6 for vitamin E, 0.8 for selenium, and 0.4 for the combination," the authors write. "Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men."
Also in JAMA this week, an international team of researchers reports that among women with high-grade serous ovarian cancer, BRCA2 mutation was associated with improved outcomes. Although the effects of BRCA mutations are fairly well-known in breast cancer, studies have produced conflicting results when it comes to ovarian cancer, the authors write. For this study, the team analyzed genomics and clinical data on 316 high-grade serous ovarian cancer cases, and found that BRCA2 mutations were associated with significantly better overall survival, five-year overall survival, and progression-free survival, compared with wild-type BRCA. The mutation was also associated with with a significantly higher sensitivity to primary chemotherapy, the team adds. However, neither BRCA1 mutations or methylation was associated with prognosis. "Among women with high-grade serous ovarian cancer, BRCA2 mutation, but not BRCA1 deficiency, was associated with improved survival, improved chemotherapy response, and genome instability compared with BRCA wild-type," the authors write.