TUESDAY, May 3 (HealthDay News) -- Watchful waiting when you have low-grade prostate cancer that hasn't spread won't affect your risk of dying from the disease up to 15 years after your initial diagnosis.
That's the conclusion of a new study that appears in the May 4 issue of the Journal of the American Medical Association.
"For men who have chosen to 'follow' low-grade disease, this study reaffirms that their choice was probably prudent," said study author Dr. Peter Albertsen, chief of urology at the University of Connecticut Health Center. "The vast majority of men with low-grade prostate cancer die of other causes."
The findings are in stark contrast to a recent Swedish study that found a threefold increase in prostate cancer mortality after 15 years. According to Albertsen, it was those findings that prompted his researchers to conduct the current analysis.
But Dr. Peter Gann, who wrote an accompanying editorial in the same issue of the journal, said neither study is definitive for prostate cancer patients.
"The key thing patients want to know is, 'Am I out of the woods yet?'" said Gann, a professor of preventive medicine at Northwestern University's Feinberg School of Medicine. "But, as long as the mortality rate isn't zero after a time, that question can't be answered."
Each year, more than 230,000 American men are diagnosed with prostate cancer, and about 30,000 die from the disease, according to the American Cancer Society (ACS). While one in six men will get prostate cancer during his lifetime, only one man in 33 will die of the disease. Symptoms include problems with urination, blood in the urine or semen, painful ejaculation, and pain in the back, hip or pelvis, the ACS says.
An important measure of the severity of prostate cancer is the Gleason score. The Gleason score is a method of grading cancer cells or tissue removed during a biopsy. The higher the score, the more likely it is the cancer will spread. A Gleason score of two through four is low, five through seven is intermediate, and eight through 10 is considered high. Treatment options for prostate cancer include watchful waiting, hormone therapy, surgery or radiation therapy. The choice of treatment depends on the severity of the cancer.
The new study included 767 men who were diagnosed with localized prostate cancer between 1971 and 1984. The men were all Connecticut residents and between 55 and 74 years old at the time of diagnosis. The average age of the study participants at the time of diagnosis was 69.
For treatment, the men chose either watchful waiting -- which includes careful monitoring for progression of the disease -- or delayed hormone therapy. The researchers followed the participants for an average of 24 years.
During the first 15 years of follow-up, the overall death rate from prostate cancer was 33 per 1,000 person-years. After 15 years, the overall death rate from prostate cancer was 18 per 1,000 person-years, a difference the researchers said wasn't statistically significant.
What did make a significant difference was the Gleason score. There were only six prostate cancer deaths per 1,000 person-years during 20 years of follow-up for those with a low Gleason score. Those with a high Gleason score of eight to 10 fared much worse, with 121 deaths per 1,000 person-years. Men with mid-range Gleason scores fared somewhat better: a Gleason score of seven resulted in a prostate cancer mortality rate of 65 per 1,000 person years. There were 30 deaths per 1,000 person-years for men with a Gleason score of six and 12 per 1,000 for men with a Gleason score of five.
"What we're all struggling with is what to do with Gleason six patients," said Albertsen. "Men with higher scores are destined to progress. Six is the most troubling, because we're not sure who needs treatment. We can't tell which will progress."
Gann said deciding on a treatment course for prostate cancer is still very much an individualized choice that men must make with the help of their doctors.
"Prostate cancer seems to have more variability than some other cancers, and because of screening we see a lot more disease than we might otherwise have," said Gann.
"If you're diagnosed with prostate cancer, you need to make a decision about whether to undergo aggressive treatment or not," explained Gann. "Most men will fall into the middle category, and this is not an easy decision for them."
For men with localized prostate cancers and low Gleason scores, the decision may be easier. The study authors concluded, "The annual mortality rate from prostate cancer appears to remain stable after 15 years from diagnosis, which does not support aggressive treatment for localized, low-grade prostate cancer."
To learn more about prostate cancer, visit the American Cancer Society.