Prostate Cancer Stages

After examination and biopsy, doctors will "stage" and "grade" prostate cancer with a system of letters and numbers.

Grade: Grade refers to the expected aggressiveness of the tumor based on the biopsy. The most common grading system is the Gleason system. Grades 1 and 2 are closer in appearance to normal glands, and are the slowest growing, better behaving tumors. Grades 4 and 5 have more variations in size of tumor cells and loss of glandular appearance, and are the more aggressive tumors. Usually there are 2 grades assigned to each biopsy, based on the most and the second-most extensive disease in the biopsy. Adding those 2 grades together gives a Gleason sum or score, such as 3+3 = 6/10, or 3+4 = 7/10. Gleason scores of 2-4 are considered well-differentiated (good), Gleason scores 5-7 are moderately-differentiated, and Gleason scores of 8-10 are poorly-differentiated (bad).

Stage: The clinical stage of a cancer is the extent of disease, whether it is localized, spread regionally, or spread more widely to lymph nodes or bones. A bone scan is performed when the PSA is quite high (over 20 or so), or the Gleason grade is 8-10. CT scan is often requested, but is of little value in predicting lymph node involvement unless the PSA is very high. A Prostascint scan, which is a nuclear scan of soft tissues, may be used to determine lymph node spread in patients with PSA over 30. Surgery gives the most complete staging, as the entire specimen is examined microscopically (pathologic stage), but many patients, such as those undergoing radiation, are managed on the basis of clinical staging.

A system of staging used by the National Cancer Institute and most doctors is called TNM (Tumor Nodes Metastases) Staging. Some patients may see or hear these types of symbols in their lab reports or discussions with their doctors.

Primary Tumor Staging: T

Lymph Node Staging:N

Distant Metastatic Spread Staging: M