Given the existing level of knowledge, it is difficult to compare accurately the risks and benefits of screening. Doctors and patients need to consider the potential morbidity and mortality prevented by treatment versus the potential morbidity and mortality caused by treatment. The NCI is carrying out treatment and screening trials to address some of these questions. Each man should discuss the issues with his physician and, recognizing the uncertainties that may be involved, choose the best approach for himself. Doctors then may take biopsies of various sectors of the prostate using tiny hollow needles inserted through the rectum.
Biopsies are the only definitive way to determine if prostate cancer is present.
Staging also depends on the extent and location of cancer outside the confines of the prostate. Another important measure, the Gleason score, gauges the probable aggressiveness of the tumor based on the cellular differences of the cancer. Tumor cells that look similar to normal cells tend to be less aggressive, while those distributed randomly with uneven edges are likely to spread rapidly. Two numbers, each from 1 to 5, are assigned. The higher the numbers when the two are added, the more aggressive the tumor is likely to be.