Seeds Beat Out Watchful Waiting
Men With Prostate Cancer Less Likely to Die if They Get Radiation Seed Implants
Oct. 31, 2007 (Los Angeles) -- Older men with prostate cancer who chose treatment with radiation seed implant therapy or surgery cut their risk of dying of the disease by more than half, compared with those who opt for close observation, researchers report.
"This is the first time it’s been shown that seed implants are better than watchful waiting in terms of survival," researcher Ester H. Zhou, MD, PhD, of Case Western Reserve University School of Medicine in Cleveland, tells WebMD.
The study involved about 11,000 men 65 and older with newly diagnosed cancer that was confined to the prostate or that had only spread to nearby tissues. About 30% chose a strategy of "watchful waiting," which involves close monitoring for tumor growth.
Over the next seven years, those who got seed implants within six months of being diagnosed were about 55% less likely to die of the cancer than those who chose watchful waiting. Surgery to remove the prostate cut the risk of dying of the disease by up to 75%.
The findings were presented at the American Society for Therapeutic Radiology and Oncology’s (ASTRO) annual meeting.
To Treat or Not to Treat
There has been a long debate in the medical community about the value of treatment to destroy cancer cells vs. watchful waiting, also known as active surveillance.
Because prostate cancer often grows so slowly it may never become life-threatening, many of these men, particularly older men, may die of causes other than the cancer. But in some men, the cancer will spread beyond the prostate without treatment. Then it may no longer be curable.
Treatment usually involves surgical removal of the prostate, external beam radiation therapy, or radiation seed implants.
In external beam radiation therapy, a beam of high-dose radiation is aimed at the prostate to kill cancer cells.
In radiation seed implant therapy, or brachytherapy, surgeons implant tiny radioactive seeds into the prostate gland. The seeds deliver high-dose radiation directly to the prostate for a predetermined length of time.
Watchful waiting consists of close monitoring with periodic digital rectal exams, biopsies, and PSA (prostate-specific antigen) blood tests. Rising PSA levels can be a sign of prostate cancer spread in men with early cancer.