Staging and Grading
Staging Systems
Cancers are evaluated according to whether they are still localized (still within the prostate gland) or have spread beyond the original site. A tumor’s stage is an indication of how far it has spread from its original site. Staging is evaluated based on the TNM staging system.
The TNM Staging System describes the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).
My Take: The TNM grading system is only one aspect of the information needed to determine the best course of treatment for you. Effective treatment decisions should be based on full consideration of your total picture.
The Gleason Grading System
The Gleason grading system is used exclusively in evaluating prostate cancer cells. A pathologist will assess how closely the cancerous cells resemble normal prostate cells. If the cancerous cells appear to resemble the normal prostate tissue very closely, they are said to be very well differentiated and are considered to be Gleason grade 1. These tumors tend to be less aggressive. On the other hand, if the cells in question look fairly irregular and very different from the normal prostate cells, then they are very poorly differentiated and are assigned a Gleason grade 5. Grades 2-4 are used for tumors that fall between grades 1 and 5, with higher numbers corresponding to faster growing tumors.
Because prostate cancer tissue often comprises a mixture of areas that have different grades, the pathologist will closely examine the areas that make up the largest portion of the tissue. Gleason grades are then given to the two most commonly occurring patterns of cells.
Once the two grades have been assigned, a Gleason score can be determined by adding together the two Gleason Grades. The Gleason score that results will be a number from 2 to 10. Scores on the higher end of the Gleason grading system (7 through 10) usually indicate a more serious prognosis.
My take: Although Gleason scores are a key feature in the consideration of the proper treatment course, it’s important to keep in mind that this is still only one of several factors that contribute to your total picture that will ultimately lead to the best treatment options.