The TNM (T: tumor; N: lymph node; M: metastasis) staging method is commonly used to guide treatment and determine the prognosis of prostate cancer.
The specific stages are as follows.
T1 stage refers to clinically occult tumor, which can neither be palpated nor detected by imaging.
T1a refers to incidental tumor volume less than 5% of the prostate tissue.
T1b refers to incidental tumor volume greater than 5% of the prostate tissue.
T1c refers to tumors found by puncture biopsy
T2 stage means a tumour confined to the prostate
T2a tumours involving ≤1/2 of a single lobe of the prostate
T2b tumor involving more than 1/2 of a single lobe of the prostate, but limited to that single lobe.
T2c tumors involving both lobes of the prostate.
T3 tumor breaching the prostate peritoneum.
T3a tumor invading up to the outer peritoneum.
T3b tumor invading one or both seminal vesicles.
T4 Tumor fixation or invasion of adjacent tissues and organs. For example: bladder neck, external urethral sphincter, rectum, anal levator and pelvic wall.
Nx: regional lymph nodes cannot be evaluated.
N0: no lymph node metastasis.
N1: regional lymph node metastasis.
Mx: distant metastases could not be evaluated.
M0: no distant metastases.
M1: with distant metastases.
M1a with lymph node metastases other than regional lymph nodes.
M1b bone metastasis.
M1c metastasis to other tissues and organs.