In the online edition of the Journal of Clinical Oncology, Dr. Michael Zelefsky and colleagues from Memorial Sloan-Kettering report a retrospective study comparing radical prostatectomy (RP) and external beam radiotherapy (XRT) for localized prostate cancer (CaP). The clinical endpoints assessed were distant metastases (DM) and cancer-specific mortality.

The cohort included 2,380 patients with localized CaP treated with either open RP by one of two experienced surgeons or intensity modulated radiotherapy (IMRT) to a dose level of at least 81Gy. There were 1,318 RP patients and 1,062 IMRT patients in the final data analysis. RP patients treated with adjuvant or salvage XRT after RP were included in the dataset (79 patients, 6%). The pelvic lymph nodes were not included in the IMRT treatment protocol, and 3 to 6 months of androgen-deprivation therapy (ADT) was given to 597 patients (56%). Salvage therapy was given to 107 (76%) of 141 RP patients with biochemical recurrence. 59 of these received XRT and 35 received ADT/chemotherapy. 48 men were given ADT or chemotherapy without XRT. Among IMRT patients, salvage ADT was given to 88 of 207 men (43%) with a biochemical recurrence.

IMRT treated men were older than RP treated men and had higher PSA levels, clinical stages, and biopsy Gleason scores. The 5-year biochemical recurrence-free probability predicted by the Kattan nomogram was 84% for RP patients and 80% for IMRT patients. 21 patients in the RP group and 48 in the IMRT group developed DM. The 8-year probability of freedom from metastatic progression was 97% for RP patients and 93% for IMRT patients. After adjustment for preoperative nomogram risk probability, age, high vs. lower risk groups followed by treatment (RP vs. IMRT). The adjusted absolute difference in DM-free survival rates was similar for men with low-risk disease (1.9% difference in 8-year metastasis-free survival), 3.3% for intermediate risk, but 7.8% for high-risk patients favoring RP. The analysis was similar after accounting for salvage therapy that was provided to both groups.

A total of 8 and 22 patients died in the RP and IMRT groups, respectively. The corresponding 8-year probabilities of cause-specific survival were 98.6% for RP patients and 95.3% for IMRT patients. The hazard ratio for death due to CaP for RP in reference to IMRT patients was 0.32 and the inclusion of the short-term ADT with IMRT did not influence the model. The 8-year Kaplan-Meier probability of CaP death from RP was 3.8% compared with 9.5% for IMRT.

Zelefsky MJ, Eastham JA, Cronin AM, Fuks Z, Zhang Z, Yamada Y, Vickers A, Scardino PT
J Clin Oncol. 2010 Mar 20;28(9):1508-13
doi:10.1200/JCO.2009.22.2265

Written by UroToday.com Contributing Editor Christopher P. Evans, MD, FACS

UroToday – the only urology website with original content written by global urology key opinion leaders actively engaged in clinical practice. To access the latest urology news releases from UroToday, go to: www.urotoday.com

Copyright © 2010 – UroToday