If your doctor finds cancer in your prostate gland, the next step is to find out the stage, or extent, of the disease. The goal of staging is to determine whether the cancer has spread and, if so, what areas of the body are affected. Various blood and imaging tests can help pinpoint the stage of the disease. Treatment decisions depend on these findings.

TNM is the common staging system used in the United States for prostate cancer. The system evaluates and describes:

• The size and location of the primary prostate tumor (T).
• If the cancer has metastasized to lymph nodes (N).
• If the cancer has metastasized elsewhere (M).

There are two types of stages:

1. Clinical Stage — Based on the digital rectal exam, needle biopsy or transrectal ultrasound results.
2. Pathological Stage — Based on surgical removal of the entire prostate gland, the seminal vesicles and possibly lymph nodes.

T Stages (Primary Tumor)

Clinical

• TX — Primary tumor cannot be assessed.
• T0 — No evidence of primary tumor.
• T1 — Cannot detect tumor with imaging tests.
• T1a — Less than five percent of the prostate is affected by the tumor.
• T1b — More than five percent of the prostate is affected by the tumor.
• T1c — Tumor identified by needle biopsy, PSA elevated.
• T2 — Tumor confined within prostate.
• T2a — Tumor affects one-half of one lobe or less.
• T2b — Tumor affects more than one-half of one lobe but not both lobes.
• T2c — Tumor affects both lobes.
• T3 — Tumor extends through the prostate capsule.
• T3a — Tumor extends beyond the prostate capsule.
• T3b — Tumor invades seminal vesicle(s).
• T4 — Tumor is fixed or invades surrounding areas, such as the bladder neck, external sphincter, rectum, levator muscles and/or pelvic wall.

Pathologic

• pT2 — Tumor confined to the prostate.
• pT2a — Tumor affects one-half of one lobe or less.
• pT2b — Tumor affects more than one-half of one lobe but not both lobes.
• pT2c — Tumor affects both lobes.
• pT3 — Tumor extends beyond the prostate.
• pT3a — Tumor extends beyond the prostate.
• pT3b — Tumor invades seminal vesicle(s).
• pT4 — Tumor invades the bladder, rectum.

N Stages (Regional Lymph Nodes)

A N0 stage indicates the cancer has not spread to the lymph nodes. N1 indicates the cancer has spread to one or more pelvic lymph nodes.

Clinical

• NX — Regional lymph nodes were not assessed.
• N0 — Tumor has not spread to regional lymph nodes.
• N1 — Tumor has spread to regional lymph nodes.

Pathologic

• pNX — Regional lymph nodes were not assessed.
• pN0 — Regional lymph nodes not affected by tumor.
• pN1 — Regional lymph nodes affected by tumor.

M Stages (Distant Metastasis)

A M0 stage indicates the cancer has not spread beyond the local lymph nodes, while M1 indicates the cancer has metastasized to distant lymph nodes and/or to other organs.

• MX — Distant metastasis cannot be assessed.
• M0 — No distant metastasis.
• M1 — Distant metastasis.
• M1a — Non-regional lymph nodes affected by tumor.
• M1b — Bones affected by tumor.
• M1c — Other sites affected by tumor with or without bone disease.