Doctors have suspected that radiation therapy helped prevent patients from dying of prostate cancer, but had little scientific proof. Now, Richard Valicenti, M.D., assistant professor of radiation oncology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, and his colleagues have found the first conclusive evidence that radiation therapy helps patients with localized prostate cancer live longer.
He presents his team's findings May 16 at the annual meeting of the American Society of Clinical Oncology in Atlanta.
Prostate cancer, the most common cancer in elderly men, tends to be a slow growing disease men frequently die with, not from. Doctors often question whether surgery or radiation provide any real benefit for the older patient.
The researchers retrospectively examined the results of 1560 patients who had received radiation therapy alone for prostate cancer. The patients were among those treated between 1975 and 1995 in four separate trials conducted by the Radiation Therapy Oncology Group, a federally funded cancer clinical trials group. The average follow up was eight years, with some patients seen for as many as 12 years.
They found that in dividing men into four categories according to the likelihood of having a more dangerous cancer, those with the worst prognoses benefited the most from receiving higher doses of radiation. After they adjusted statistically for disease severity and age, they found that patients who received higher-than-usual radiation doses were 32 percent less likely to die from prostate cancer.
"I think these results will change how we evaluate the use of higher radiation doses and new radiation treatment systems for prostate cancer," Dr. Valicenti says.
Dr. Valicenti's group wanted to try to answer the question, "Is there an
advantage to treating prostate cancer locally with radiation therapy?" To
accomplish this, they evaluate
Contact: Steve Benowitz
Thomas Jefferson University