Men diagnosed with localized prostate cancer are blessed with several treatment options and cursed with too little information to choose between them.
Although randomized clinical trials comparing the risks and benefits of surgery against more conservative management are underway, the results won't be available for 15 years. Meanwhile, an estimated 317,000 men in the United States will be diagnosed with prostate cancer this year and 41,400 will die of the disease.
A multi-institutional study led by surgeons at the University of Chicago fills an important part of that information gap. Their findings, reported in the August 28 issue of JAMA, offer the best available estimates of long-term survival following surgical removal of the prostate for localized cancer.
The researchers found that surgery was quite effective and that the tumor grade - how close to normal the cells from the tumor appeared under the microscope - was the best predictor of long-term survival.
Ten years after surgery, only six percent of men with grade 1 (well differentiated) tumors had died from prostate cancer. Twenty percent of those with grade 2 tumors (moderately differentiated) died within ten years and 23 percent of those with grade 3 tumors (poorly differentiated) died within ten years.
Most of the men with grade 1 tumors were cured by the surgery. Ten years after the operation, 87 percent had no evidence of cancer that had spread beyond the prostate. For those with grade 2 tumors, however, metastasis-free survival fell to 68 percent and for those with grade 3 tumors it dropped to 52 percent.
"These are likely to become the standard figures that physicians quote to their patients when they discuss surgical removal of a cancerous prostate," said Glenn Gerber, M.D., assistant professor of surgery at the University of Chicago Medical Center and lead author of the study.
Previously, physicians could only offer patients a list of widely varying published results from individual centers.
Reliable outcome statistics are particularly important because of the continuing controversy about treatment for men with prostate cancer. Because these tumors usually progress slowly and often are detected late in life, many older men decide not to have surgery, reasoning that they are likely to die of something else before their cancer causes symptoms.
Since doctors can't always predict who will benefit from surgery - it depends on the patient's age and life expectancy and the speed with which the tumor will grow and spread - patients must weigh the risks and benefits, factor in their other health problems and make an informed choice about a course of treatment.
"It becomes a high-stakes numbers game for patients as they balance the odds of the disease spreading versus the discomfort and possible complications from surgery," said Gerber. "If you have to play this game, you want to start out with the best available numbers."
The study compiled surgical results from eight university medical centers - six in the U.S. and two in Europe - that have been performing large numbers of prostatectomies for an extended period. It involv>
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The outcomes, from a broad range of patients from varied geographic areas treated by multiple surgeons in diverse settings, were consistent between all eight medical centers.
Unfortunately, there is no equivalent study of men with similar disease who chose radiation or watchful waiting instead of surgery.
The closest parallel may be a meta-analysis reported from the University of Chicago (New England Journal of Medicine, January 27, 1994) of ten-year survival rates for patients who chose watchful waiting instead of surgery. Although direct comparison is difficult - because of differences in the study populations, in distribution of tumor grade and stage, and in physicians - the two studies suggest a survival advantage for many patients treated with surgery.
The authors add the caveat, however, that men who choose watchful waiting tend to be older or have other diseases that make them poor candidates for surgery.
"Until ongoing studies are completed, the results of these studies provide us with the best opportunity to begin to compare the long-term results for relatively similar patients treated by surgery or watchful waiting, and to provide patients with information that can help them decide on a treatment," said co-author Gerald Chodak, M.D., professor of surgery at the University of Chicago.
Additional authors of the paper include statistician Ronald Thisted and surgeon Daniel Rukstalis from the University of Chicago; surgeons Peter Scardino and Makoto Ohori from Baylor, Hubert Frohmuller from the University of Wurzburg, Fritz Schroeder from Erasmus University, David Paulson from Duke, Anthony Middleton from the University of Utah, Joseph Smith from Vanderbilt, and Paul Schellhamer from Eastern Virginia.