The antioxidant supplement beta-carotene is safe for use during radiation therapy treatments for prostate cancer. It does not escalate the risk of prostate cancer death or metastases, despite previous safety concerns, according to a study published in the May issue of the International Journal of Radiation Oncology • Biology • Physics.
Because radiation therapy relies on the pro-oxidant effects of DNA, which entails damaging tumor cells while leaving normal cells unharmed, some scientists have suggested that supplemental antioxidants may impair the oxidizing effects of radiation and potentially lead to cancer recurrence.
To determine if antioxidants could potentially counteract the pro-oxidant effects of radiation therapy and increase a patient’s risk of death or metastases, researchers followed 383 prostate cancer patients who were randomized to receive either beta-carotene or placebo. The study was the largest of its kind to date, and its primary end point was prostate cancer death or bone metastases.
When comparing the patients who took the antioxidant beta-carotene versus those who did not, researchers found no significant disparities in lethal outcomes.
“This study shows that antioxidant supplementation with beta-carotene during radiation therapy does not appear to detract from the benefit of radiation therapy,” Danielle Margalit, MD, MPH, lead author of the study and a radiation oncologist at the Dana-Farber Cancer Institute in Boston, said. “It also suggests that patients may continue to eat a well-balanced diet that contains foods with natural sources of antioxidants at the recommended daily amount,” she added.
Source: ASTRO.