How is Prostate Cancer Staged?
Cancer stage is a measure of the extent of tumor involvement. Each type of cancer has a unique set of instructions for staging. However, they all share the same basic format, known as TNM. The American Joint Committee on Cancer publishes guidelines for staging. The T stands for tumor and describes the tumor size. N is for lymph node involvement. M represents whether metastasis is present, i.e. tumor spread to a distant site. For prostate cancer, the PSA and Gleason score are also used to determine stage.
There are two types of staging, clinical and pathologic. Clinical stage is based on the results of physical exam (including rectal exam), labs, prostate biopsy, and any imaging tests. Pathologic stage is only determined after surgery, when the prostate can be examined in its entirety along with any lymph nodes removed. Pathologic stage is thus more accurate in determining true tumor extent.
T1: Tumor cannot be felt or seen with imaging but is found incidentally on biopsy
T2: Tumor cannot be felt on digital rectal exam or see it with imaging, but appears to be confined to the prostate
T3: Tumor extends outside the prostate and possibly into the seminal vesicles
T4: Tumor has spread beyond the prostate
N0: Nodes are free of tumor
N1: Tumor involves one or more nodes
M0: Tumor has not spread beyond the prostate
M1: Metastases are present
After the T, N, and M categories have been determined, this information is combined with Gleason score and PSA to determine stage grouping. This ranges from I (the least advanced) to IV (the most advanced). Stage grouping allows selection of the best treatment options and prediction on outcome (prognosis).
This information is contained within the pathology report. Ask for a copy of your report. Become engaged in your care. Ask your pathologist any questions.