For men with localized prostate cancer, radical prostatectomy (RP) can provide good long-term control of the disease1; however, the risk of extraprostatic disease and metastasis still exists for one-third of the population that undergo RP.2 In a recent randomized, phase 3, controlled trial, investigators discovered that conventional postoperative radiotherapy may significantly improve biochemical progression-free survival (PFS) and local control compared with a wait-and-see policy in men who undergo RP.
Focusing on the Data
The EORTC (European Organisation for Research and Treatment of Cancer) 22911 trial included men age 75 years and younger with untreated cT0-3 prostate cancer and was conducted at 37 institutions across Europe.1 All the men in the study were randomly assigned 1:1 to postoperative irradiation (n= 502) or to a wait-and-see policy (n= 503) until biochemical progression. In this trial, postoperative radiation therapy consisted of 60 Gy of conventional radiotherapy to the surgical bed for 6 weeks. Biochemical progression was defined as an increase in PSA (prostate-specific antigen) greater than 0.2 ug/L that was confirmed on 2 separate occasions, which were at least 2 weeks apart.
The study showed a greater number of the men who received immediate radiotherapy after RP remained disease-free compared to the men in the wait-and-see group after 10 years; out of the men who received immediate radiotherapy after RP, 39.4% died compared to 61.8% of the wait-and-see group. The late adverse effects of any grade were more common in the postoperative irradiation arm of the study with a 10-year cumulative incidence of 70.8% versus 59.7% in the wait-and-see arm.
“These long-term results reassure us of the continued benefit and safety of radiation therapy after prostatectomy for a large proportion of men with locally advanced or high-risk prostate cancer,” said lead study investigator Michel Bolla, MD, who is with the Department of Radiation at the Centre Hospitalier Universitaire A Michallon, Grenoble, France.
The patients who received postoperative irradiation were also much less likely to require androgen deprivation therapy (ADT) for disease progression at 10 years of follow-up; however, the researchers found clinical PFS was not significantly improved with postoperative radiation therapy after 10 years and radiotherapy had no effect on the 10-year rates of distant cancerous spread or overall survival.
“I was surprised that there was no overall or cancer-specific survival benefit in long-term follow-up,” Judd Moul, MD, Professor of Surgery and Director of the Duke Prostate Center at Duke University Medical Center, Durham, North Carolina, told ChemotherapyAdvisor.com. “We now have PSA to follow men closely after surgery and this study tells me that it is probably okay to wait and apply salvage EBRT (external beam radiation therapy) when the PSA level is above 0.2 ng/mL, but less than 1.0 ng/mL when we pull the trigger for postoperative EBRT.”