The largest ever trial of postoperative radiotherapy in prostate cancer shows men may be spared the procedure after surgery.
New results from the late breaking RADICALS-RT trial presented at the ESMO Congress 2019 in Barcelona, Spain found that men with prostate cancer may be spared radiotherapy after surgery.
The largest ever trial of postoperative radiotherapy in prostate cancer, RADICALS-RT found no difference in disease recurrence at 5 years between men who routinely had radiotherapy shortly after surgery compared with men who had radiotherapy later if the cancer returned.
In the trial, researchers enrolled 1396 patients after surgery for prostate cancer from the UK, Denmark, Canada, and Ireland. Men were randomly allocated to postoperative radiotherapy or the standard approach of observation only, with radiotherapy kept as an option if the disease recurred.
At a median follow-up of 5 years, progression free survival was 85% in the radiotherapy group and 88% in the standard care group.
Self-reported urinary incontinence was worse at 1 year in 5.3% of patients receiving radiotherapy compared with 2.7% who had standard care. Radiation Therapy Oncology Group grade 3/4 urethral stricture was reported at any time in 8% of the radiotherapy versus 5% of the standard care groups. Researchers noted that longer follow-up is needed to report on survival and on the primary outcome of freedom from distant metastases.
The findings were later confirmed by a meta-analysis that included 3 randomized trials, combining results of RADICALS with 2 similar trials RAVES and GETUG-AFU17, comparing adjuvant radiotherapy with early salvage radiotherapy following prostatectomy for men with localized prostate cancer.
The trial included 2151 men, of whom 1074 were randomized to adjuvant radiotherapy and 1077 men were randomized to early salvage radiotherapy. The results revealed that of those enrolled in the trial, 395 men (37%) have commenced salvage treatment to date.
The analysis found no evidence that adjuvant radiotherapy improves event free survival compared with early salvage radiotherapy (HR 1.12; 95% CI 0.88-1.42; p=0.37). Based on these results, the difference in 5-year event free survival is likely only to be approximately 1%.
The researchers said that the findings are a strong case that observation should be the standard approach after surgery and radiotherapy should only be used should cancer return.