Prostate cancer with a Gleason score of 6 or lower can still be considered Stage 1 and only is only found in the prostate, rather than having spread to other areas of the body. Other factors to consider when determining the stage of prostate cancer are the prostate-specific antigen, or PSA, level and the percentage of the prostate where the cancer is visible or detectable.
The Gleason score is a set standard of grading the severity of cancerous prostate tissue. It is determined by examining the prostate tissue under a microscope. The Gleason score can be as low as 2 or as high as 10.
Gleason scores of 6 and below mean that the cancer is considered still in the first stage of progression. Gleason scores of 7 or higher are considered Stage II or higher. However, a Gleason score of 6 or below does not always indicate that the cancer is still Stage 1. A patient can have a Gleason score ranging anywhere between 2 and 10 and still have Stage III or Stage IV prostate cancer if the cancer has visibly spread to other areas around the prostate. In general, a low Gleason score means that the tissue appears more like normal, healthy tissue, while a high Gleason score means that the tissue does not appear normal and is more likely to spread.