Jan. 8, 2007 -- One of the longest ever follow-up studies of radioactive "seed" implants for prostate cancerprostate cancer shows the treatment to be highly effective in combination with conventional external radiation.
Three out of four patients in the study remained disease free at least 15 years after treatment ended, with intermediate-risk patients faring almost as well as those considered to have a low risk of dying from their cancercancer.
The outcomes compared favorably to the best results reported among surgically treated patients, says John E. Sylvester, MD, of the Seattle Prostate Institute.
Sylvester and colleagues followed 223 patients with localized prostate tumors for at least a decade and a half after treating the men with external beam radiotherapy and internal seed implants.
"The results that we found in this group of intermediate- to high-risk patients with localized disease have not been beaten by any other treatment," Sylvester tells WebMD.
Each year in the U.S. roughly 240,000 men are diagnosed with prostate cancer, according to the American Cancer Society (ACS). And for most new patients, decisions about which treatment to have or whether or not to even be treated at all are not clear-cut.
Prostate cancer treatments include surgery to remove the prostate gland, external radiation, cryotherapy (in which the tumor is treated by freezing it), radioactive seed implants, chemotherapy, hormone therapy, and watchful waiting.
Seed implants, also called brachytherapy, are small radioactive pellets about the size of a grain of rice. The pellets are implanted into the prostate; they deliver radiation to the prostate cancer from the inside.
Most good-prognosis patients who choose seed implants do not receive other treatments, Sylvester says. But patients considered to have more aggressive tumors may get seed implants and external-beam radiation.
The patients in the newly reported follow-up study received seed implants about four weeks after completion of the short daily external beam radiation treatment. Most were able to carry on their normal daily activities while undergoing treatment.
Making Informed Choices About Treatment
Fifteen years later, the overall relapse-free survival rate among the men was 74%, with survival rates even higher than this for men with low- to intermediate-risk cancers.
Sylvester says the long-term findings prove that the combination treatment is an effective prostate cancerprostate cancer treatment.
The study is published in the January issue of the International Journal of Radiation Oncology*Biology*Physics.
"We now have 15-year results which look excellent, and you really can't ask for longer follow-up than that in prostate cancercancer patients," he says.
American Cancer Society spokesman Len Lichtenfeld, MD, tells WebMD that the long-term data will help patients and clinicians make more informed decisions about treatment. But he adds that the findings may not make those decisions any easier.
"We now have a number of treatment options for prostate cancer," says Lichtenfeld, who is deputy chief medical officer for ACS. "What we don't have is an effective way of saying for sure which treatment is best for which patient."
It is not clear from the study if the patients would have fared equally well with either brachytherapy (seed implants) or external-beam radiation therapy alone, he says.
Lichtenfeld says men facing a diagnosis of prostate cancer need to learn all they can about different treatments because decisions about treatment are usually not simple.
"A patient's age and general health, the size and grade of the tumor, and even whether a man is willing to travel to get a specific treatment may all factor into decisions about treatment," he says. "A patient and his family should learn as much as they can from unbiased sources. Even then they might not have definite answers. But at least they will know the options."