Prostate cancer staging is the process by which physicians categorize the risk of cancer having spread beyond the prostate, or equivalently, the probability of being cured with local therapies such as surgery or radiation.
Prostate cancer stage can be assessed by either clinical or pathological staging methods.
Clinical staging usually occurs before the first treatment and tumor presence is determined through imaging and rectal examination, while pathological staging is done after treatment once a biopsy is performed or the prostate is removed by looking at the cell types within the sample.
There are two schemes commonly used to stage prostate cancer in the United States. The most common is promulgated by the American Joint Committee on Cancer (AJCC), and is known as the TNM system, which evaluates the size of the tumor, the extent of involved lymph nodes, and any distant spread and also takes into account cancer grade.
T1-clinically inapparent, non palpable or visible by imaging
T1a-incidental histologic finding, ≤5% of resected tissue
T1b-incidental finding, >5% of resected tissue
T1c-tumor identified by needle biopsy, or any PSA elevation
T2-palpable or visible tumor, confined within the prostate
T2a-tumor involvement ≤1/2 of one lobe
T2b-tumor involvement of one lobe
T2c-tumor involvement of both lobes
T3-tumor extends through the capsule
T3a-tumor with extracapsular extension unilaterally or bilaterally
T3b-tumor involvement of the seminal vesicle
T4-tumor is fixed or invades adjacent structures
T4a-tumor invades bladder neck, external sphincter or rectum
T4b-tumor invades levator muscles or fixed to pelvic sidewalls
N0-no cancer cell in lymph nodes
N1-one positive lymph node smaller than 2 cm
N2-more than one positive node, or one that is 2-5 cm
N3 any positive node > than 5 cm
M0-no cancer spread outside the pelvis
M1-cancer spread outside the pelvis
Stage I-T1N0M0, Gleason score 6 or less, PSA less than 10 or T2a, N0 M0, Gleason score 6 or less, PSA less than 10.
Stage IIa- T1N0M0, Gleason score of 7, PSA less than 20 or T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20, or T2a or T2b, N0 M0, Gleason score of 7 or less, PSA less than 20
Stage IIb-T2c, N0M0, any Gleason score, any PSA or T1 or T2, N0 M0, any Gleason score, PSA of 20 or more, T1 or T2, N0 M0, Gleason score of 8 or higher, any PSA
Stage III-T3, N0, M0, any Gleason score, any PSA
Stage IV-T4, N0, M0, any Gleason score, any PSA, or any T, N1, M0, any Gleason score, any PSA or any T, any N, M1, any Gleason score, any PSA