Testosterone replacement therapy viable in patients with localized prostate cancer

Key Points

Atlanta-Testosterone replacement therapy (TRT) did not increase the risk of biochemical recurrence in hypogonadal men with localized prostate cancer, according to a study reported at the AUA annual meeting in Atlanta.

During a median follow-up of 28 months, four of 103 men treated with TRT had suspected PSA recurrence compared with eight of 50 men who underwent radical prostatectomy at the same time but did not receive TRT. Although serum testosterone increased significantly in men who received TRT, mean PSA increased only slightly in the entire cohort and not at all among men with high-risk features.

"We conclude that TRT in men with prostate cancer treated with radical prostatectomy leads to a rise in serum testosterone," said first author Alexander Pastuszak, MD, PhD, a urology resident at Baylor College of Medicine in Houston working with Mohit Khera, MD, MBA, MPH, and colleagues. "There were no changes in hemoglobin or hematocrit. There was a statistically, but not clinically, significant rise in PSA, but only in non-high-risk subjects."

To continue the evaluation of TRT in prostate cancer, investigators identified 103 men who started TRT following radical prostatectomy for localized prostate cancer during 2003 to 2011. They identified 50 men who underwent radical prostatectomy during the same time period but did not receive TRT.

The 103 TRT recipients consisted of 77 men who had low- or intermediate-risk prostate cancer and 26 who had high-risk cancer. Dr. Pastuszak and colleagues defined high risk as postoperative pathology with a Gleason score ≥8, positive surgical margins, or lymph node involvement.

Laboratory data included serum total testosterone, free testosterone, estrogen, sex hormone binding globulin, hemoglobin, hematocrit, and PSA. Baseline values were obtained before the start of TRT and then at 3-month intervals thereafter, with follow-up out to more than 3 years after prostatectomy.

The study and control groups differed with respect to several baseline characteristics, but notably the proportion with T3 disease: three of 103 versus eight of 50. The proportion of men with T3b disease differed significantly: two versus eight, including two of 26 high-risk patients in the study group versus five of 15 in the control group (p=.03).

At baseline, total testosterone averaged 261 ng/dL in the TRT group, increasing to 366 ng/dL at 12 to 18 months, 415 ng/dL at 18 to 24 months, 460.5 ng/dL at 24 to 36 months, and 491 ng/dL beyond 36 months (p<.001 vs. baseline at all time points).

With respect to PSA measures, the TRT group had a mean of 0.004 ng/mL, which was the same in high-risk and non-high-risk men. The mean value for the entire cohort increased at each measurement, reaching 0.009 ng/mL beyond 36 months (p<.001 vs. baseline). The baseline value in the control group was 0.007 ng/mL and did not change significantly throughout follow-up.

PSA increases slightly in non-high-risk men

Separate analyses of the high- and non-high-risk groups showed that the mean PSA value increased significantly only in the non-high-risk subgroup of men receiving TRT (0.004 ng/mL to 0.009 ng/mL, p<.001). In the control group, the mean PSA value did not change significantly at any point in time during follow-up.

"We continue to need larger cohorts for study," said Dr. Pastuszak. "This is a retrospective study, so therefore, we need clinical trials evaluating TRT in the setting of prostate cancer. Ultimately, there are a lot of questions regarding the impact of testosterone on prostate cancer, and we need to understand that at the molecular level."