Equivalent Psa Outcomes For Younger (<= 55) Vs. Older Men With Radiation Treatment Of Prostate Cancer

Treatment equivalency with radiation (RT) vs surgery has been acknowledged by both ASTRO and the AUA. Nevertheless, patterns of referral and practice continue to result in more young men undergoing prostatectomy relative to radiation. The aim of this study is to demonstrate comparable outcomes for a given RT modality regardless of age. PSA data were prospectively analyzed with consent in 564 patients treated by a single physician. Age grouping and follow-up (FU) time was ≤55 yrs (n = 45, 46 months (mos); 56–70 yrs (n = 355, 53 mos); >70 (n = 164, 51 mos); minimum FU was 30 mos (range 30–108 mos). Using NCCN risk stratification, 1/3 of each age group were low, intermediate and high risk. Treatments for age ≤55 years consisted of EBRT to 75.6–81 Gy (3dCRT or IMRT) in 25%, permanent brachytherapy (PRSI) in 10%, or combined EBRT (45–50 Gy) + PRSI in 70%. Treatments for age >55 years consisted of EBRT to 75.6–81 Gy (3dCRT or IMRT) in 25%, permanent brachytherapy (PRSI) in 25%, or combined EBRT (45–50 Gy) + PRSI in 50%. Hormonal therapy (ADT) was used overall in 2/3 for a median duration of 16 mos (≤55 yrs), 18 mos (56–70 yrs), or 20 mos (>70 yrs), with longest duration for high risk patients. All patients had normalize testosterone (>150 ng/ml) at the time of most recent PSA determination or sooner. Thus, we defined biochemical failure in patients with normalized testosterone levels (>150 ng/ml) and with a minimum FU of 30 months after completion of RT as “PSA nadir + 2 ng/ml.” Using Cox regression analysis, age showed no significant difference as a predictor of biochemical failure (p = 0.95). Similarly, there was no significant difference among the three age groups using the Kaplan-Meier estimate (p = 0.30) However, there were clinically significant differences among the groups by 7 years of FU. The actuarial cure rates at year five were 98%, 96% and 93% for ≤ 55, 56–70, and >70 years, respectively; at 7 years FU, these rates were 96%, 91% and 84%, respectively (Figure). In this population with normalized testosterone levels and long term FU, biochemical cure rates appear to be similarly excellent across age groups at least up to 5 years of FU, beyond which young patients may even do better than their older counterparts. Most of the differences in PSA outcome appear to be explained by confounding due to differences in pre-treatment risk status among the 3 age groups. We found no evidence of higher PSA failure rates in patients ≤55 years compared to those older.