Radiotherapy reduces the risk of prostate cancer returning

This study examined whether patients with prostate cancer who receive radiotherapy after surgery have a decreased chance of the cancer returning.

Surgical removal of the prostate (radical prostatectomy) is the most common treatment for patients with prostate cancer. After surgery patients can receive additional treatment such as radiotherapy (adjuvant radiotherapy). It is also possible for patients to receive no additional treatment until there are signs of cancer returning (wait-and-see approach).

Prostate-specific antigen (PSA) is a protein produced by the prostate. Levels of PSA are elevated in patients with prostate cancer. After successful prostate removal PSA levels continue to be monitored regularly to make sure the cancer has not returned. If PSA levels increase it is known as biochemical recurrence.

307 patients with cancer extending through the prostate wall (stage T3) were randomly assigned to group 1 (148 patients) or group 2 (159 patients). Patients in group 1 received radiotherapy after surgery. Patients in group 2 received no radiotherapy after surgery but were monitored for any signs of cancer (wait-and-see approach). All patients had undetectable PSA levels after surgery and none of the patients had any signs of cancer in the lymph nodes.

During the follow-up visits patients were monitored for signs of cancer. After 10 years, 56% of patients who received adjuvant radiotherapy never developed any of these signs compared to 35% of patients in the wait-and-see group. In other words, adjuvant radiotherapy reduced the risk of biochemical recurrence by 49%.

There was no difference in overall survival of patients between the two groups. There was also no difference in the chance of the cancer spreading to other locations between the two groups. 

The authors concluded that radiotherapy after surgery reduces the risk of biochemical recurrence.

This study may not have included enough patients for accurate statistical analysis of patient survival or cancer metastasis (spread of the cancer beyond the prostate).