Absence of Relationship Between Steroid Hormone Levels and Prostate Cancer Tumor Grade

Abstract

To analyze the relationship between plasma testosterone and estradiol levels on prostate biopsy and radical prostatectomy Gleason scores in a cohort of patients with newly diagnosed prostate cancer. Patients with prostate cancer evaluated at the Dana-Farber Cancer Institute from 2001 to 2005 who were enrolled in a prospective sample banking protocol were eligible for this study. Stored plasma was processed for total testosterone, total estradiol, and sex hormone-binding globulin levels using enzyme-linked immunosorbent assays. The frequency of high-grade biopsy and radical prostatectomy Gleason scores (>6) was the primary endpoint. Univariate and multivariate logistic regression analyses were performed to determine the relationship between the hormone levels and high-grade Gleason scores while adjusting for sex hormone-binding globulin, age, body mass index, and prostate-specific antigen. A total of 539 patients were included in this study, 199 of whom underwent radical prostatectomy. The median prostate-specific antigen level was 5.1 ng/dL, and 67% of the cancers were not palpable. The Gleason score was 2-6, 7, and 8-10 in 53%, 37%, and 10% of the cancers, respectively. On univariate analysis of the high-grade biopsy and radical prostatectomy Gleason score, the total testosterone, total estradiol, and estradiol-to-testosterone ratio were not significant as continuous or categorical variables. Adjusting these results for sex hormone-binding globulin level, body mass index, age, and prostate-specific antigen level did not change the conclusions, and these results were unchanged when categorizing high-grade prostate cancer as Gleason score 8-10. No relationship was found between the circulating steroid hormone levels and the Gleason score in this cohort.