Post-op rad therapy slows progression of prostate cancer in 60% of men

Radiotherapy immediately following removal of the prostate has long-term benefits for preventing the biochemical progression of prostate cancer, with more than 60 percent of men remaining disease-free after a decade, according to a study published online first in The Lancet.

The results, based on follow-up data from the European Organisation for Research and Treatment of Cancer trial 22911, provide reassurance of the safety of radiation therapy after prostatectomy, according Michel Bolla, MD, from the Centre Hospitalier Universitaire A Michallon in France.

“They also suggest that younger patients and those with positive surgical margins are most likely to benefit from immediate radiotherapy, whereas in older adults (aged 70 years plus) it could have detrimental effects,” Bolla said in a release.

Although removal of the prostate is one of the main treatments of the disease, the risk of recurrence for patients whose cancer has spread beyond the prostate can be anywhere from 10 to 50 percent. Radiotherapy is often prescribed to improve outcomes, and Bolla and colleagues sought to confirm whether previously reported progression-free survival was sustained.

A total of 1,005 patients with high-risk prostate cancer were followed for a median of 10.6 years. Patients were randomly assigned to post-operative irradiation of 60 Gy for six weeks or to a wait-and-see approach until biochemical progression, which was defined as an increase in prostate-specific antigen concentration to > 0.2 µg/L.

Radiotherapy significantly improved biochemical progression-free survival compared with the wait-and-see policy, according to the authors. Of the patients who received postoperative irradiation, 39.4 percent had biochemical progression, compared with 61.8 percent of patients who did not receive radiotherapy. Better local control and a reduced need for hormonal therapy also was demonstrated in the radiotherapy group.

The results were not entirely positive, as Bolla and colleagues reported that late adverse effects were more frequent in the radiotherapy group compared with the wait-and-see group, with a 10-year cumulative incidence of 70.8 percent and 59.7 percent, respectively. While postoperative radiotherapy demonstrated benefit for preventing biochemical progression, 10-year rates of clinical progression and overall survival were not affected.

In a linked comment, Jason A. Efstathiou, MD, of Massachusetts General Hospital in Boston, questioned whether there is enough evidence to determine who should and should not receive postoperative radiotherapy. “Ultimately, the decision to treat needs multidisciplinary input. When surgery has probably not cured a patient, prospective data still support postoperative radiation. The onus is on the uro-oncology team (surgical, radiation, and medical) to discuss postoperative radiation with the patient, address optimal timing of initiation when it is used, and to provide justification when it is not.”