Polymorphisms in the glutathione S-transferase M1, T1, and P1 genes and prostate cancer prognosis

Abstract

Background: Polymorphisms in glutathione S-transferase (GST) genes can increase oxidative stress, which may affect cancer prognosis. The aim of this study was to examine associations between GSTM1, T1, or P1 genetic variants and prostate cancer outcomes.

Methods: A population-based cohort of men (n = 752) from King County, Washington, diagnosed with prostate cancer in 1993-1996, and under long-term surveillance for mortality completed a follow-up survey about prostate cancer recurrence/progression. Cox PH models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for deaths from prostate cancer or other causes and prostate cancer recurrence/progression.

Results: There were 50 prostate cancer-specific deaths, 65 deaths from other causes, and 143 recurrence/progressions events during an average 9.6 years of follow-up. The adjusted HR for prostate cancer mortality was 3.8 (95% CI 1.6-8.9) among Caucasian men with the GSTM1-null genotype. There were no differences, however, in mortality from other causes or prostate cancer recurrence/progression between men with GSTM1-null versus not-null genotypes. The GSTT1 and GSTP1 genotypes were not associated with any of these outcomes.

Discussion: Results suggest that the GSTM1 genotype may be a useful biomarker to identify patients at higher risk for fatal prostate cancer.