How is prostate cancer staged?

Once prostate cancer has been diagnosed by a prostate biopsy, the physician must stage the disease.  Staging the disease determines the extent of the cancer (i.e., the "T" stage) and whether the cancer has spread from the prostate to other tissues such as the seminal vesicles, the lymph nodes and/or the bones. The T stage is determined by using the DRE and other imaging procedures like the ultrasound scan, CT scan, MRI scan, or MR spectroscopy scan.








The T stage is divided into the following categories:
T1: Doctor is unable to feel the tumor
T1a: Cancer is found incidentally during a transurethral resection (TURP) for benign prostatic enlargement. Cancer is present in less than 5% of the tissue removed and is low grade (Gleason < 6)
T1b: Cancer is found after TURP but is present in more than 5% of the tissue removed or is of a  higher grade (Gleason > 6)
T1c: Cancer is found by needle biopsy that was done because of an elevated PSA
T2: Doctor can feel the tumor when a digital rectal exam (DRE) is performed but the tumor still  appears to be confined to the prostate
T2a: Cancer is found in one half or less of only one side (left or right) of the prostate
T2b: Cancer is found in more than half of only one side (left or right) of the prostate
T2c: Cancer is found in both sides of the prostate
T3: Cancer has begun to spread outside the prostate and may involve the seminal vesicles
T3a: Cancer extends outside the prostate but not to the seminal vesicles
T3b: Cancer has spread to the seminal vesicles
T4: Cancer has spread to adjacent organs, such as the urethral sphincter, rectum, bladder, and/or wall of the pelvis
Imaging tests, such as radionuclide bone scan, CT scan, MRI, and MR spectroscopy may help assess whether the cancer is still confined to the prostate or spread elsewhere. To determine if the cancer has spread to the lymph nodes or bones, the physician may order a CT or MRI scan of the pelvis. Sometimes follow-up images are needed to evaluate abnormalities found on the bone scan. These tests are not recommended for men with a Gleason grade lower than 7 and a PSA level lower than 10 ng/ml as they rarely show disease.