Radiation After Prostatectomy Keeps Some Patients Disease Free Longer

Prostate cancer patients who have an elevated prostate-specific antigen (PSA) blood test after surgery need radiation therapy, preferably before their PSA reaches a level of 1 ng/mL, according to a new study.

The study reviewed 51 patients who had been treated with radiation therapy following a radical prostatectomy, said Dr. David Koeplin, a radiation oncologist at the University of California, San Francisco. Some 90% of the patients had disease that had spread beyond the prostate, he said. Patients with more advanced disease are more likely to have a detectable PSA level after surgery, added Dr. Koeplin.

Most of the patients (73%) who were treated with radiation therapy before the postoperative PSA reached a level of 1 ng/mL remained clinically and biochemically free of disease 4 years after surgery. This compares to 38% of patients who were treated with radiation after PSA levels rose to between 1 and 10 ng/mL, Dr. Koeplin told the American Radium Society at its annual meeting in Paris.

None of the patients with a PSA level of 10 ng/mL or more at the time of radiation was cured of his disease, said Dr. Koeplin.

"An elevated PSA level after surgery tells us how we have done and if we need to do more for these patients. Our study shows that patients with evidence of residual disease following surgery can be helped by radiation therapy. "We're more likely to help them the sooner we find out cancer remains," he said. An elevated PSA, in many instances, is the earliest indication that cancer is still present, Dr. Koeplin added.

The bottom line is that a lot of men who have surgery also need radiation therapy but aren't receiving it, he said. We need to carefully monitor all prostate cancer patients who have had surgery, and if they have a detectable PSA level, they most likely need radiation therapy," he contended.