International journal of radiation oncology biology physics vol:78 issue:3 pages:S29-S29
52nd Annual Meeting of the American-Society-For-Radiation-Oncology San Diego, CA, OCT 31-NOV 04, 2010
Purpose/Objective(s): From 1992 to 2001, 1005 patients (pts) entered a randomized controlled EORTC trial comparing immediate
external beam irradiation (P-XRT) versus wait-and-see (W&S) for pts with positive surgical margins or pT3 after radical prostatectomy
(RP) (Lancet 2005). We report the 10-year follow-up results.
Materials/Methods: Eligible pts were # 75 years, had WHO performance status 0-1; and cT0-3N0M0 (UICC 1983) prostate
cancer with one or more pathological risk factors of: capsular perforation, positive surgical margins, or invasion of the seminal
vesicles. P-XRT (60 Gy in 6 wks conventional external irradiation to the surgical bed) was started within 4 months after RP.
The trial’s primary endpoint was biochemical progression-free survival. Results at 5 years were presented after an interim analysis
(p\0.02). Updated results are presented at 2a = 0.047. The trial is registered with ClinicalTrials.gov, number NCT00002511.
Results: Five hundred three pts entered the P-XRT arm and 502 W&S. The median age was 65 years (range, 47-75). The median
pre- and post-operative PSA was 12.4 and 0.2 ng/mL, with 69.5% of pts having a postoperative PSA#0.2 ng/mL. After 10.6 years
median follow-up, the 10-year biochemical PFS rate (time to twice confirmed PSA increase over nadir or first clinical failure or
death) was 60.6% (CI: 55.7-65.9%) on P-XRT versus 41.1% on W&S (CI: 36.4-45.8%); HR = 0.49 (CI: 0.41-0.59), p \
0.0001. The 10-year clinical PFS rate was, respectively 70.3% (CI: 65.5-74.6) and 64. 8% (CI: 59.8-69.3%); HR = 0.81 (CI:
0.65-1.01); p = 0.054. At 10 years, the cumulative incidence of loco-regional failure was decreased from 16.6% to 7.3% with
P-XRT (p\0.0001). The 10-year cumulative incidence of distant metastases- did not differ (p . 0.1) with 10y-rates of 10.1%
with P-XRT and 11.0% with W&S. Overall survival did not differ (p . 0.1) with 10-year survival rates of 76.9% and 80.7%, respectively.
The results were similar in the subgroup with postoperative PSA#0.2 ng/mL. In the W&S group, 56.4% of relapsing
patients received salvage irradiation and 22.9% androgen deprivation therapy, 3.4% other treatments and the remainder no active
treatment thus far. The cumulative rate of grade 3 toxicity at 10 years was 5.3% after P-XRT and 2.5% after W&S (p = 0.052).
Conclusions: Conventional post-operative radiotherapy improves biochemical PFS and local control without significantly impacting
upon distant metastases or overall survival at 10 years.