Radiation After Surgery May Not Be Necessary Among Men With Prostate Cancer

Men with prostate cancer could be spared having to undergo radiation after surgery given that a recent study found no difference in disease recurrence at five years between those who did and did not utilize the adjuvant therapy.

Moreover, these findings could lead to patients experiencing far fewer side effects. “The good news is that in future, many men will avoid the side-effects of radiotherapy,” study author Dr. Chris Parker, from The Royal Marsden NHS Foundation Trust and Institute of Cancer Research in London, said in a press release. “These include urinary leakage and narrowing of the urethra, which can make urination difficult. Both are potential complications after surgery alone, but the risk is increased if radiotherapy is used as well.”

In the RADICALS-RT trial, researchers enrolled 1,396 patients after surgery for prostate cancer, and randomized them to receive either postoperative radiotherapy or the standard approach of observation only (in this group, radiotherapy was only kept as an option if the disease recurred).

At a median follow-up of five years, progression free survival (the time from treatment to disease progression or worsening) was 85% in the radiotherapy group, compared with 88% in the standard care group.

At one year after surgery, self-reported urinary incontinence was worse in the radiotherapy group (5.3%), compared with those who underwent observation (2.7%). In addition, Radiation Therapy Oncology Group (RTOG) grade 3/4 urethral stricture was reported at any time in 8% versus 5% of the radiotherapy and standard care groups, respectively.

“The results suggest that radiotherapy is equally effective whether it is given to all men shortly after surgery or given later to those men with recurrent disease,” Parker said. “There is a strong case now that observation should be the standard approach after surgery and radiotherapy should only be used if the cancer comes back.”

The findings were also confirmed in a collaborative meta-analysis that included three randomized trials comparing adjuvant radiotherapy with early salvage radiotherapy following prostatectomy for men with localized prostate cancer.

“The meta-analysis provides the best opportunity to assess whether adjuvant radiotherapy may still have a role in some groups of men, and to investigate longer term outcomes,” author of the analysis Dr. Claire Vale, of the MRC Clinical Trials Unit at University College in London, said in the release.

The analysis was comprised of 2,151 men, including 1,074 who were randomized to adjuvant radiotherapy and 1,077 men were randomized to early salvage radiotherapy. Of those randomized to early salvage radiotherapy, only 37% started salvage treatment to date.

Similarly, the analysis did not find a significant difference supporting the use of adjuvant therapy to improve prostate cancer from recurring, compared to early salvage radiotherapy. Based on these results, the difference in five-year event free survival is likely only to be around 1%, according to the release.

“Results of the meta-analysis…provide greater evidence to support the routine use of observation and early salvage radiotherapy,” Vale concluded.

Dr. Xavier Maldonado, from the Hospital Universitari Vall d’Hebron in Barcelona, commented on the study findings, nothing that these results could shorten the duration of treatment, allow for better use of resources and potentially reduce expenses.

“However, strict follow-up (of patients) will be needed to identify patients requiring salvage radiotherapy,” Maldonado said. “We need to develop genomic classifiers to help decide the best management strategy for each patient — whether it should include surgery and/or radiotherapy, and at which time points.”