Prostate cancer TNM staging with histopathologic grade per AJCC 7th edition.
TX: tumor cannot be assessed T0: no evidence of primary tumor
T1: clinically nonapparent tumor not palpable nor visible by imaging T1a: tumor incidental histologic finding in 5% or less of tissue resected T1b: tumor incidental histologic finding in more than 5% of tissue resected T1c: tumor identified by needle biopsy (e.g., because of elevated PSA)
T2: tumor confined within the prostate* T2a: tumor involves 50% or less of one lobe T2b: tumor involves more than 50% of one lobe but not both lobes T2c: tumor involves both lobes
T3: tumor extends through the prostate capsule** T3a: extracapsular extension (unilateral or bilateral) T3b: tumor invades seminal vesicle(s)
T4: tumor is fixed or invades adjacent structures other than seminal vesicles: bladder neck, external sphincter, rectum, levator muscles, and/or pelvic wall
NX: regional lymph nodes were not assessed N0: no regional lymph node metastasis N1: metastasis in regional lymph node(s)
MX: distant metastasis (M)*** cannot be assessed (not evaluated by any modality) M0: no distant metastasis M1: distant metastasis M1a: nonregional lymph node(s) M1b: bone(s) M1c: other site(s) with or without bone disease
GX: grade (G) cannot be assessed G1: well-differentiated (slight anaplasia, Gleason score of 2–4) G2: moderately differentiated (moderate anaplasia, Gleason score of 5-6) G3-4: poorly differentiated or undifferentiated (marked anaplasia, Gleason score of 7–10)
*Tumor that is found in one or both lobes by needle biopsy but is not palpable or reliably visible by imaging is classified as T1c.
**Invasion into the prostatic apex or into (but not beyond) the prostatic capsule is classified as T2 not T3.
***When more than one metastasis site is present, the most advanced category pM1c is used.