TUESDAY, Aug. 12, 2008 (HealthDay News) -- The latest update from a European study that has followed men with prostate cancer for more than a decade leaves the debate about the advantages of aggressive treatment versus "watchful waiting" undecided.
The advantage in survival seen for men who underwent surgery to remove the prostate disappeared after 10 years. While deaths attributed to cancer continued to be lower among those having surgery, the overall death rate for both groups was the same, according to the researchers with the Scandinavian Prostate Cancer Group.
The meaning of the study for men now being diagnosed with prostate cancer is uncertain, because the study began before the use of testing for prostate-specific antigen, today's primary method of diagnosis, the researchers added.
"In settings with a large proportion of PSA-detected tumors, the relative reduction in risk of death following radical prostatectomy [removal of the gland] might be somewhat larger or similar to that in our study, but the absolute reduction would be smaller," they wrote.
The findings were published online Aug. 12 in the Journal of the National Cancer Institute.
Dr. Yu-Ning Wong, an oncologist at the Fox Chase Cancer Center in Philadelphia, said it's "unclear how these results apply to the patients we are taking care of today. They show how many questions remain unanswered."
Wong led a study that found an apparent benefit in survival for men who had aggressive surgical treatment of early prostate cancer. But it wasn't a randomized, controlled trial -- the gold standard for medical research.
"Basically, I don't think we know the right answer about what to do," she said.
Prostate cancer is diagnosed in about one of every six American men. There's currently no way to distinguish between a cancer that will grow so slowly that it poses little danger to life from one that can grow aggressively enough to be fatal. A common medical saying is that "more men die with their prostate cancer than of it."
Uncertainty about prostate cancer treatment has led to a new federal recommendation that men over 75 should not have PSA tests because the risks of treatment outweigh the benefits.
A final answer about whether surgery and other aggressive treatment is preferable to merely watching the course of the disease will not come for years, Wong said. A controlled trial is under way in Europe, and one is planned for the United States, she said.
Meanwhile, the decision about treatment versus watchful waiting must be made for each individual, Wong said.
"I have discussions with a patient about his other medical conditions, his age, his willingness to receive treatment that may have long-term side effects, weighed against the risk that he may develop an aggressive cancer," she said.
Stephen Zeliadt, a research scientist at the Fred Hutchinson Cancer Research Center in Seattle, said the new study "does provide evidence that intervention in the form of surgery does have a curative effect for some men. The question is, which men?"
Another question is whether the study results apply to "a screening population" of men who have PSA tests, Zeliadt said. "With screening, you catch a lot of different types of cancer, and also at different ages. There is no information in the study on the age of detection."
So, Zeliadt added, this study doesn't help solve the prostate cancer riddle. "It probably makes it even more confusing," he said.
Dr. Peter T. Scardino, chairman of the department of surgery at Memorial Sloan-Kettering Cancer Center in New York City, said the study did offer an important finding: "The big benefit of treating potentially lethal prostate cancer comes early, in the first five to 10 years."
The study also "showed lots of benefits of surgery but did not find any benefit from surgery for men over the age of 65," he noted.
To learn more about prostate cancer, visit the U.S. National Cancer Institute.