In one study, published in a recent issue of The Journal of the American Medical Association (JAMA), researchers at Stanford University Medical Center studied a group of 379 men with localized prostate cancer who had been treated with radical prostate surgery. The researchers compared several features of the tissues removed during surgery with the patients? subsequent outcomes.

As part of their study, the researchers used a modification of the Gleason system, the method most often used for summarizing how abnormal the cancerous tissue appears under a microscope. The Gleason system assigns grades on a scale of 1-5 and scores on a scale of 2-10. The modified Gleason scale used in the study looked at the percentage of the cancer classified as Gleason grades 4 and 5. Other factors the researchers studied included cancer volume (the size of the cancer), spread to lymph nodes, prostate weight, prostate-specific antigen (PSA) level in the blood before surgery, the usual (not modified) Gleason score, involvement of blood vessels and lymph vessels, and spread to seminal vesicles (two small sacs next to the prostate that store semen).

According to the study, the percentage of Gleason grades 4 and 5 and cancer volume were found to best predict prostate cancer progression. Spread to lymph nodes and involvement of blood or lymph vessels also were significant in predicting progression. Several other features previously thought to be very useful, such as spread into the outer covering (capsule) of the prostate or cancer cells at the edge of the specimen, were not found to be significant in this study. Thomas A. Stamey, MD, lead author of the study, said narrowing the number of variables used in making a prognosis will have a huge impact on future research. "It?s important that we know what?s really driving this cancer," he said.

In a second study, which was also published recently in JAMA, Johns Hopkins University researchers examined the progress of a group of patients who had their prostates removed. The researchers wanted to determine the factors that would predict the course of further disease.

Their results suggested the length of time it took for the PSA level to rise initially, how quickly it rose, and the Gleason score of the original tumor all could be used to predict risk of metastasis, or spread, of the cancer. Generally, the longer it took for PSA levels to rise after surgery, the longer it took for metastases to become apparent. And the longer it took for metastases to grow, the longer the men survived. This information will be useful in helping men with rising PSA levels after surgery choose among further treatment options.

For example, a patient whose PSA levels rise within two to three years and continue rising rapidly, and whose cancer has a high Gleason grade, may choose more aggressive treatment. But a patient whose PSA levels don?t rise for four or five years and whose initial cancer is low-grade may decline further treatment. Thus, some patients could avoid the side effects of unnecessary treatment.

Alan Partin, MD, one of the study?s authors, said their results offer additional information to prostate cancer patients. Even with rising PSA levels, 82 percent of the men studied were cancer-free 15 years after initial treatment. Only 34 percent of those who had elevated PSA levels developed metastases. Dr. Partin said the study can help patients empower themselves to make more rational decisions about further treatment. "When [PSA levels rise], it is not an indication that things are going to get bad quickly," Dr. Partin said.

LaMar McGinnis, MD, medical consultant to the American Cancer Society (ACS), believes the studies will help to more precisely define the factors that can be used to measure a patient?s future outlook. "These are both very significant studies," adds Dr. McGinnis. "The findings can direct clinical research and open the door to clinical trials for further answers."