Analysis of Single Nucleotide Polymorphisms (SNPs) and Dose-volume Parameters on Predicting for Rectal Toxicity, Erectile Dysfunction, and Urinary Morbidity Following Treatment for Prostate Cancer Using Radiotherapy

The purpose of this study was to determine whether dosimetric parameters combined with genetic single nucleotide polymorphism (SNP) information improve the ability to predict for adverse events including rectal toxicity (proctitis), erectile dysfunction (ED), and urinary morbidity (UM) among men treated for prostate cancer using radiotherapy (RT). Analysis was completed by grouping patients based on dose-volume parameters and determining whether the presence or absence of a SNP showed an increased susceptibility to one of the endpoints. We identified 6 SNPs for proctitis, 2 SNPs for ED, and 8 SNPs for UM that showed a significant increase in the incidence of adverse events for patients receiving high doses while showing no effect on patients receiving low doses. Results indicate that for patients treated with high doses, genetics may determine which men are more susceptible to toxicity. Thus, genetic information may be of value in treatment decision-making for men diagnosed with prostate cancer.