TUESDAY, Aug. 17, 2004 (HealthDayNews) -- Adding only six months of follow-up hormone therapy to radiation treatment for prostate cancer saves as many lives as three years of the hormone regimen does, researchers report.
"The big message to give here is that there is the same reduction in death rate with the shorter therapy," said study leader Dr. Anthony V. D'Amico.
The scientists followed 206 men with prostate cancer that had not spread beyond the gland, and compared radiation-only treatment with radiation plus six months of drug treatment designed to reduce production of male sex hormones. As expected, the five-year survival rate was higher for those who got the drug treatment, 88 percent vs. 78 percent, says the report in the Aug. 18 issue of the Journal of the American Medical Association.
What is noteworthy is that the improved survival rate is essentially the same as what was reported for patients in a landmark European study who got three years of hormonal treatment, explained D'Amico, a professor of radiation oncology at Brigham and Women's Hospital in Boston.
And that improvement was accompanied by a major reduction in side effects such as hot flashes, weight gain, impotence and breast growth that go along with the prolonged hormonal treatment, he added.
Treatment for prostate cancer is in a state of flux, said Dr. Michael J. Zelefsky, a professor of radiation oncology at Memorial-Sloan Kettering Cancer Center in New York City.
The only study until now that has shown a survival benefit of hormonal therapy plus radiation is the European trial, he said. In practice, many American cancer centers give a shorter course of hormone therapy "because it's tough to get a patient through even two years" because of the side effects, Zelefsky explained.
It is now more or less standard practice to give combined radiation-hormonal therapy to patients whose prostate cancer has not spread outside the gland, but the length of therapy can vary, he said.
A more definitive answer may emerge from a current study that is comparing six months of hormonal treatment with the three-year course, Zelefsky said.
But the amount of radiation that is most effective is also in question, he added. Patients in the newly reported study received a dose that is regarded as standard. "But many studies in this country consistently have found that higher radiation doses are better," Zelefsky said.
One encouraging fact, D'Amico said, is that most cases of prostate cancer in the United States are being diagnosed in their early stage, because of intensive efforts to screen for the disease. "It has spread beyond the prostate in only 1 to 2 percent of all patients we see in this country," he said.
Meanwhile, two reports in the Aug. 18 issue of the Journal of the National Cancer Institute described advances in understanding the genetics of prostate cancer.
One study of 426 families with histories of prostate cancer found evidence of a gene that increases the risk of the malignancy on chromosome 17, scientists at the Translational Genomics Research Center in Phoenix and Wake Forest University School of Medicine report. They also identified four other regions that might hold susceptibility genes.
And scientists at Umea University in Sweden reported that men with a specific mutation in a gene designated MIC-1, which is believed to play an important role in infection-related inflammation, appear to have a lowered risk of prostate cancer.
The National Cancer Institute tells you what you need to know about prostate cancer.