ESTRO 2024 - Abstract Book

S2488

Clinical - Urology

ESTRO 2024

Androgen deprivation therapy (ADT) is a mainstay therapy for patients with prostate cancer that has been demonstrated to improve oncologic outcomes. Side effects due to suppression of testosterone from ADT are common; therefore, counseling patients about the long-term toxicity associated with ADT, including those associated with delayed testosterone recovery, is key. Existing studies have reported a wide range of average testosterone recovery intervals (4-18 months) with a recent meta-analysis suggesting that a large fraction of patients may never recover normal testosterone levels after cessation of ADT (1 – 5). Using body mass index (BMI) and diagnosis of diabetes or pre-diabetes as proxies for metabolic syndrome, we hypothesized that patients with metabolic dysfunction were at increased risk of non-recovery of testosterone after cessation of ADT and, if recovery were achieved, had a longer time to recovery of testosterone than healthy individuals.

Material/Methods:

Electronic medical records of 1903 patients with prostate cancer who received leuprolide from our institution between January 2000 and January 2023 were reviewed. After including only patients who received leuprolide for a duration of 4 to 40 months as a part of curative-intent therapy, 581 patients were included in our analysis. Patient characteristics including age, stage, prostate-specific antigen (PSA) level, Gleason score, BMI, history of diabetes (type 1 or 2), abnormal fasting serum glucose or hemoglobin A1c (“diabetes/prediabetes”), duration of ADT (injection doses and dates), and serum testosterone levels were collected. We estimated the time to testosterone recovery (TTR) based on the date of the last leuprolide injection to the first date on which serum testosterone rose to laboratory-defined normal limits after cessation of ADT. TTR was analyzed using the Kaplan-Meier method, the log-rank test, and the Cox Proportional Hazard models using R.

Results:

Of the 581 patients available for analysis, the mean age was 74.6 years (range 46.8 to 97.2 years). About one-third (34.6%) of patients had history of diabetes/prediabetes. A majority of patients were overweight or obese (38.4% BMI >30, 42.0% BMI 25 to 29.9, and 19.6% BMI < 24.9). In terms of duration of ADT, 16.4% received >24 months, 5.0% 24 months, 31.2% 18 months, 46.3% 6 months, and 1.2% <6 months. The median follow-up time was 31.5 months (range 6.0 to 100.2 months). A total of 370 men (63.7%) achieved testosterone recovery with a mean TTR of 9.7 months and a median TTR of 6.3 months (range 0.03 to 77.0 months). We found that obesity was a risk factor for non-recovery (p<0.001), with 39.2% obese patients did not achieve testosterone recovery compared to 34.6% non obese patients. The median TTR was 5.5 months for patients with BMI of <25, 6.2 months with BMI 25 to 29.9, and 7.4 months with BMI >30 (p<0.05) among those who achieved testosterone recovery. We also found that patients with diabetes/prediabetes (43.8%) had an increased risk of non-recovery compared to those without (32.4%; p=0.002), with a significant difference in median TTR 6.8 months among patients with diabetes/prediabetes vs. 6.1 months without (p=0.03).