Metabolomic Insights into Prostate Cancer Treatment and Relapse.

: High-risk prostate cancer is often treated with combined androgen deprivation therapy (ADT) and radiotherapy (RT). Blood biomarkers may enable treatments to be tailored to individual patients. Metabolomics, the study of small-molecule alterations in blood, is promising, and lipids are emerging as potential markers of poor prognosis. This study aims to investigate metabolic changes during prostate cancer treatment and their correlation to disease outcome. : This study included 136 blood plasma samples from 35 patients with high-risk prostate cancer treated with RT and ADT, recruited from the Uppsala/Umeå Comprehensive Cancer Consortium (U-CAN) project. Blood samples were collected before, during, and after treatment and analyzed at Metabolon Inc. (Durham, NC, USA). To study differences in metabolic levels during treatment, three different sampling time points were considered: before ADT, in-between ADT and RT, and after RT. Both multivariate (orthogonal projections to latent structures, OPLS) and univariate analyses were performed, where statistical significance in combination with a large fold change was considered indicative of a substantial change. : Significant changes in metabolite levels were observed. Many of the significant metabolites for the whole course of treatment were also significant during ADT but not during RT, indicating that changes during ADT dominated the overall treatment. Changes were found to be especially common in steroids and fatty acids. Multivariate analysis revealed significant differences in metabolites between relapsing and non-relapsing patients. Among the significant metabolites were cholesterol and epiandrosterone. : Metabolomics can identify biomarkers for prostate cancer treatment response and relapse. Further studies are needed to identify patterns and individual metabolites to personalize treatment strategies for prostate cancer.