Adjuvant radiotherapy improves biochemical recurrence-free survival after radical prostatectomy

Undergoing adjuvant radiotherapy after radical prostatectomy improves biochemical recurrence-free survival while being reasonably tolerable, a recent study has found.

Researchers randomly assigned 250 prostate cancer patients with positive margins or extracapsular extension to receive either adjuvant radiotherapy (n=126; median age, 61 years) or not (n=124; median age, 62 years). Biochemical recurrence-free survival was the primary outcome.

The 10-year overall survival rate was 92 percent in the adjuvant radiotherapy group and 87 percent in controls. The resulting difference in risk was not statistically significant (hazard ratio [HR], 0.69, 95 percent CI, 0.29–1.60; p=0.4). Only one patient in each group died of prostate cancer, such that the malignancy-specific survival in either group was 99 percent.

Similarly, the 10-year metastasis-free survival rates between groups were statistically comparable (98 percent vs 96 percent; HR, 0.49, 0.09–2.68; p=0.4).

Adjuvant radiotherapy, however, proved to be significantly superior in terms of biochemical recurrence-free survival (82 percent vs 61 percent; HR, 0.26, 0.14–0.48; p<0.001). Adjusting for preoperative prostate-specific antigen, Gleason score and pT stage weakened the magnitude of the interaction but did not attenuate significance (HR, 0.30, 0.16–0.54; p<0.001).

Adjuvant radiotherapy also had an acceptable toxicity profile. Erectile dysfunction was the most common grade 3 adverse event, occurring in 37 percent and 28 percent of the treatment and control groups, respectively. This was followed by urinary incontinence, which was reported in 12 percent and 5 percent, respectively. One grade 4 adverse event developed in the radiotherapy group.