SAN DIEGO — Men whose prostate cancers are treated early with radiation therapy can expect to live almost as long as men the same age who never develop the disease, according to results of a 15-year study released Monday.
"The bottom line . . . is that there are substantial numbers of patients who, after 15 years, are cured of the disease by radiation therapy alone," said Gerald Hanks, author of the study and chairman of the Department of Radiation Oncology at Fox Chase Cancer Center in Philadelphia.
The findings are important because 1 in 11 American males will develop prostate cancer, according to the American Cancer Society. Among men, prostate cancer is the second most common form of cancer after skin cancer and the second most common cause of death after lung cancer.
Hanks' study population included 1,400 men who, in 1973, received early-stage treatment for cancers that had not yet spread elsewhere. Survival rates were highest for patients whose cancers were discovered very early and were treated solely with radiation therapy.
The study said that among patients whose cancers were discovered very early, the survival rate after 15 years was 45%, equal to the expected survival rate for men who never developed prostate cancer. For patients whose cancer was discovered somewhat later, the survival rate was about 25%.
Among patients in whom the cancer was discovered relatively late, but before it had spread, the survival rate was 21%. The study did not detail what stages of cancer qualified as "early" or "late."
Hanks said the findings make it clear that prostate cancer patients should not feel that surgery is always the most effective treatment.
"There's no evidence that surgery does any better . . . so patients should have the choice of electing surgery or radiation therapy," Hanks said. "This is just like breast cancer was 15 years ago, when women were never offered an option other than surgery . . . Elderly men need to question their doctors rather than simply saying 'yes' to surgery."
Karl Herwig, head of the Urology Division at Scripps Clinic & Research Foundation, said that the findings provide good news for patients, whether they are treated with surgery or radiation or both.
". . . It is a curable disease when we catch it early," Herwig said. "That's the nice thing about it."
Hanks' study "gives more data to support radiation therapy, which is a good, viable option," Herwig said. "What we need for both radiation and surgery is more long-term data. When we're talking about survival rates, five and 10 years aren't as important as 15 years and longer."
Nationwide, an estimated 132,000 new cases of prostate cancer will be reported in 1992, including 13,000 in California. Nationwide, 34,000 deaths will occur, including an estimated 3,400 in California.
Hanks presented the study findings at the annual meeting of the American Society for Therapeutic Radiology and Oncology in San Diego.