A recurrence of cancer after a diseased prostate is removed is not necessarily as dire as doctors once believed, and radiation could save the lives of many men with such a condition, a study found.
Until now, doctors believed that certain ominous signs, including rising levels of a protein called PSA, usually meant that the cancer had not only returned but had spread to other parts of the body and was incurable. These men generally were not offered radiation but were treated only with hormones, which can slow the disease but cannot stop it.
But the new study suggests that many of these men can be cured with radiation, because the cancer has not spread after all.
The study, published in Wednesday’s Journal of the American Medical Association, involved 501 men whose disease returned an average of about 10 months after their prostates were removed. All received radiation to treat the recurrence; half remained cancer-free an average of four years later.
Radiation changed disease's natural history
For these men, radiation “changed the natural history of that disease,” said lead author Dr. Kevin Slawin, director of the prostate center at Baylor College of Medicine in Houston.
Previous data suggest that in two-thirds of men who do not get radiation for cancer recurrence after surgery, the disease will spread elsewhere within 10 years and probably prove fatal, Slawin said.
Fewer than 20 percent of patients who suffer a recurrence get radiation treatment, known as salvage radiation, Slawin said.
Dr. Mitchell Anscher, a Duke University radiation oncologist, said salvage radiation is used too infrequently, and often too late. The study is significant and suggests that radiation is warranted for the majority of patients whose recurrence was identified via PSA levels, Anscher said.
Prostate cancer is the second-most common malignancy in men after skin cancer. It is diagnosed in more than 200,000 men nationwide each year. While surgery is usually effective, cancer recurs in about 30,000 men yearly who have their cancerous prostates removed.
After surgery, rising levels of PSA — prostate specific antigen — are usually used to diagnose a recurrence of cancer.
The results will provide useful guidance to help doctors better select which patients will most benefit from salvage radiation, Anscher said.
The study found that among patients with moderately aggressive initial prostate tumors, cancer cells at the edge of the surgically removed tissue, and a PSA level that doubled in less than 10 months after surgery, 77 men, or 64 percent, were cancer-free four years after radiation.
The success of the radiation suggests that the cancer had not actually spread beyond the pelvic area, Slawin said.