Is Age at the Time of Either Prostatectomy or Radiotherapy for Localized Prostate Cancer an Important Determinant of Outcome?

Abstract:Purpose/Objective: To study the biochemical relapse-free survival (bRFS) rates after local therapy for localized prostate cancer in different age groups. Materials/Methods: A total of 2459 patients with localized prostate cancer were treated at CCF between 1987 and 1999: 1291 with radical prostatectomy (RP), and 1168 with radiotherapy (RT). Of the RT cases, 913 had external RT (minimum 68 Gy) and 255 had radioactive seeds. All cases had available pretherapy PSA (iPSA) and biopsy Gleason (bGS), no nodal metastasis, no androgen deprivation (AD) for >6 months, >1 year follow-up, and >3 follow-up PSA levels. AD for ≤6 months was done in 26%. The frequency by T-stage was: T1-T2A in 78%, T2B-T2C in 18%, and T3 in 4%. The frequency by iPSA was: ≤10 in 66% and >10 in 34%. The frequency by bGS was: ≤6 in 66%, 7 in 25%, and ≥8 in 9%. The median follow-up was 61 months (range: 12-188). The median number of follow-up PSAs per patient was 9. The ASTRO failure definition was used. Overall, the median age was 65 years (range: 40-87). Outcomes were analyzed in 6 age groups: ≤50 years(n=72), 51-60 years (n=584), 61-65 years (n=581), 66-70 years (n=680), 71-75 years (n=429), >75 years (n=113). Results: For the entire cohort, the 5-year bRFS rate was 75%. The 5-year bRFS rates for the ≤50, 51-60, 61-65, 66-70, 71-75, >75 were 85%, 77%, 76%, 73%, 74%, and 65% respectively. For the entire cohort, the 10-year bRFS rate was 61%. The 10-year bRFS rates for the ≤50, 51-60, 61-65, 66-70, 71-75, >75 were 73%, 60%, 60%, 64%, 60%, and 61% respectively. There was no overall difference in bRFS by the 6 age groups (p=0.16). However, the difference was significant between the youngest and oldest groups (p=0.036), as seen in Fig. 1. The frequency of unfavorable tumors (T3, or iPSA>20, or bGS≥8, or both iPSA >10≤20 and bGS 7) in the age groups ≤50, 51-60, 61-65, 66-70, 71-75, >75 were 17%, 25%, 28%, 29%, 33%, and 54% respectively (p75 (54%). A multivariate analysis was performed using age (continuous), race, iPSA (continuous), bGS (continuous), stage (T1-T2A vs T2B-C vs T3), treatment (RP vs RT), AD, and year of therapy (continuous). T stage (75 (n=113). The analysis failed to show age being an independent prognosticator of bRFS (p=0.88). Conclusions: Patients age >75 years present with more aggressive tumors, and consequently have worse bRFS rates than patients age ≤50 years. The large majority of patients, ages 51 to 75 years, have comparable bRFS rates. Age, per se, is not a prognosticator of outcome after either surgery or radiotherapy for localized prostate cancer.

Q15-1331

Is Age at the Time of Either Prostatectomy or Radiotherapy for Localized Prostate Cancer an Important Determinant of Outcome?