Effect of Selenium and Lycopene on Radiation Sensitivity in Prostate Cancer Patients Relative to Controls

SIMPLE SUMMARY: Prostate cancer (PC) is the most common cancer in elderly men, but its prevention by appropriate dietary interventions remains elusive. In this study, we show that the white blood cells of PC patients presented more DNA damage than those of healthy controls and were more prone to DNA damage induced by ionising radiation. Furthermore, our results indicate that this excess of DNA damage can be explained by low levels of lycopene (a carotenoid found in some red fruits such as tomatoes) and selenium (a mineral found in protein-rich foods such as beef and Brazil nuts). The results of this study suggest that a higher intake of foods rich in lycopene and selenium may help reduce the risk of prostate cancer and DNA damage caused by ionising radiation and/or oxidative stress. ABSTRACT: Almost half of prostate cancer (PC) patients receive radiation therapy as primary curative treatment. In spite of advances in our understanding of both nutrition and the genomics of prostate cancer, studies on the effects of nutrients on the radiation sensitivity of PC patients are lacking. We tested the hypothesis that low plasma levels of selenium and lycopene have detrimental effects on ionising radiation-induced DNA damage in prostate cancer patients relative to healthy individuals. The present study was performed in 106 PC patients and 132 age-matched controls. We found that the radiation-induced micronucleus (MN) and nuclear buds (NBuds) frequencies were significantly higher in PC patients with low selenium (p = 0.008 and p = 0.0006 respectively) or low lycopene (p = 0.007 and p = 0.0006 respectively) levels compared to the controls. The frequency of NBuds was significantly higher (p < 0.0001) in PC patients who had low levels of both selenium and lycopene compared to (i) controls with low levels of both selenium and lycopene and (ii) PC patients with high levels of both selenium and lycopene (p = 0.0001). Our results support the hypothesis that low selenium and lycopene levels increase the sensitivity to radiation-induced DNA damage and suggest that nutrition-based treatment strategies are important to minimise the DNA-damaging effects in PC patients receiving radiotherapy.