Influence of Hormone Therapy and Testosterone Level on All Cause Survival after Brachytherapy for Localized Prostate Cancer
To determine the influence of neoadjuvant hormone therapy (NHT) and testosterone level (T) on all cause survival (ACS) following prostate seed implantation (PSI).
1776 men with a median age of 66 years (range 31-84) were followed a minimum of 6 years (mean 10.3, range 6-22.4) and had PSI alone or with neoadjuvant hormone therapy (NHT) and or external beam irradiation boost (EBRT). NHT was given to 948 (53.4%) for a median of 6 months (75%ile 3-9). T level was available in 1140 (64.2%) a median of 6.3 years (75%ile 3.2-9.2) following treatment. The presence of co-existing medical conditions including diabetes (AODM), coronary artery disease, alcohol use, asthma, atrial fib, other cancers, heart disease, hypertension, stroke and emphysema was determined pre-treatment. Associations were compared by two-way tables (Pearson chi-square). Survival was computed by Kaplan-Meier method with comparisons by log rank. Hazard rates (HR) were determined by Cox regression analysis.
ACS at 10 and 17 years were 88.5% and 52.9%. 10 and 17-year survival (table) was decreased with the use of NHT (p=0.004), for NHT >6 months (p<0.001), for age > 65 vs. ≤ 65 years (p<0.001), for AODM (p=0.018) and for last T < 300 ng/dL (p=0.001). None of the other comorbidities were significant. Of the 1140 men with T levels, 74 were on salvage HT. Exclusion of these men yielded a last mean T of 342.3 ng/dL (95%ile 44-645). Last T was 359.8 vs 299.7 ng/dL for men treated with 0-6 months NHT vs > 6 months (p<0.001). There were 59/440 (13.2%) deaths in men with a T<300 vs. 47/620 (7.6%) for T≥300 (OR 0.538, 95%CI 0.36-0.81, p=0.002). Cox regression HRs (ACS) were for age 0.284 (95% 0.172-0.469, p<0.001), NHT 0.548 (95%CI 0.382-0.786), last T≥300 1.451 (95%CI 1.014-2.076, p=0.042) and AODM 0.521 (95%CI 0.314-0.866). Cox regression HRs after exclusion of the 74 men on salvage HT were age 0.284 (p<0.001), and last T≥300 1.495 (p=0.023).</p>
A low testosterone level has a significant impact on ACS in men treated with PSI. NHT given for more than 6 months is associated with lower long-term T levels and a T < 300 ng/dL is an independent predictor of lower ACS.