Prostate Cancer Diagnosis

Executive summary by prostate cancer foundation

Cancer is a group of abnormal cells that grow more rapidly than normal cells and that refuse to die. Microscopic cancer cells develop into small clusters that continue to grow, becoming more densely packed and hard.

Although the DRE and PSA tests cannot diagnose prostate cancer, they can signal the need for a biopsy to examine the prostate cells and determine whether they are cancerous. Gleason Grading and Gleason Scores
Under normal conditions, prostate cells, just like all other cells in the body, are constantly reproducing and dying, and each new prostate cell has the same shape and appearance as all of the other prostate cells. But cancer cells look different, and the degree to which they look different from normal cells is what determines the cancer grade. "Low-grade" tumor cells tend to look very similar to normal cells, whereas "high-grade" tumor cells have mutated so much that they often barely resemble the normal cells.

The Gleason grading system accounts for the five distinct patterns that prostate tumor cells tend to go through as they change from normal cells. The scale runs from 1 to 5, where 1 represents cells that are very nearly normal, and 5 represents cells that don’t look much like prostate cells at all.

The higher the Gleason score, the less the cells behave like normal cells, and the more aggressive the tumor tends to be.

Staging the Disease
Staging determines the extent of prostate cancer. Localized prostate cancer means that the cancer is confined within the prostate. In metastatic disease, the prostate cancer is growing outside the prostate and its immediate environs, possibly to more distant organs.

Metastatic disease can also be detected through imaging studies, and often can be detected in the lymph nodes.