Prostate Cancer Stages

A prostate cancer’s stage indicates how far it has spread within the prostate, to nearby tissues, and to other organs. The stage of a cancer is one of the most important factors in selecting treatment options. It is also the most significant (but not the only) factor in predicting a man’s outlook for survival (prognosis).

A staging system is a standardized way in which the cancer care team describes the extent to which a cancer has spread. The most commonly used system in the United States is called the TNM System of the American Joint Committee on Cancer (AJCC). The TNM System describes the extent of the primary tumor (T), the absence or presence of spread to nearby lymph nodes (N), and the absence or presence of spread to distant organs (M).

The stages described here are based on the most recent version (2002) of the AJCC staging manual.

T Categories

There are actually two types of T classifications for prostate cancer.

• The clinical stage is your doctor’s best estimate of the extent of the disease based on digital rectal exam (DRE), needle biopsy, and any imaging studies that were done.
• The pathologic stage is based on surgical removal and examination of the entire prostate gland, both seminal vesicles (two small sacs next to the prostate that store semen) and, in some cases, nearby lymph nodes.

The clinical stage is used in making treatment decisions, such as whether a patient might benefit from treating the prostate cancer with surgery or radiation. However, the clinical stage may underestimate the extent of cancer spread, and if surgery is done, the pathologic stage assigned after surgery is more accurate. Men who do not have a radical prostatectomy (surgery to remove the prostate gland, seminal vesicles, and nearby tissues) do not have a pathologic T stage determined. There are 4 categories for describing the prostate cancer’s T stage.

• T1 refers to a tumor that is not felt during a digital rectal exam, but cancer cells are found in a prostate biopsy or prostatectomy specimen (if prostatectomy has been performed for benign prostatic enlargement). T1 prostate cancers can be further subclassified as T1a, T1b, and T1c.
  • T1a describes prostate cancers found incidentally (by accident) during transurethral resection of the prostate (TURP) or open prostate removal (simple prostatectomy). These are surgical procedures done to relieve symptoms of benign prostate hypertrophy (prostate enlargement that is not caused by cancer). This operation is usually done because the enlarged prostate gland presses on the urethra and makes it difficult for a man to urinate. When prostate tissue is removed and checked under the microscope, cancer may be found, even though the doctor who removed the tissue did not expect cancer to be present. T1a indicates that less than 5% of the tissue removed is cancer and more than 95% is benign.
  • T1b also describes cancers found incidentally during TURP or simple prostatectomy, but more than 5% of the removed tissue is cancer.
  • T1c cancers are found by biopsy. In these cases a core needle biopsy is usually done because the PSA blood test result was elevated, suggesting that a cancer might be present.
•  T2 means that a doctor can feel the prostate cancer by DRE and that the cancer is thought to remain within the prostate gland. This category is subclassified into T2a and T2b and T2c.
  • T2a means that the cancer is in only one side of the prostate, and is in only half (or less) of that side.
  • T2b cancers are in only one side of the prostate, but are in more than half of that side.
  • In T2c cancer, the cancer is in both sides of the prostate gland.
• T3 cancers have spread beyond the outer rim (capsule) that surrounds the gland. They have reached the connective tissue next to the prostate and/or the seminal vesicles, but have not spread to any other organs. This group is divided into T3a and T3b.
  • In T3a, the cancer is growing outside the prostate but has not spread to the seminal vesicles.
  • A T3b cancer has spread to the seminal vesicles.
• T4 means that the cancer has spread to tissues next to the prostate (other than the seminal vesicles), such as the bladder neck or its external sphincter (muscle that helps control urination), the rectum, the muscles in the pelvis, or the wall of the pelvis.

N Categories

The N category is determined by whether or not the cancer has been found in nearby lymph nodes.

• NX means that tests to detect lymph node spread have not been done.
• N0 means that the cancer has not spread to any lymph nodes.

• N1 means spread to nearby lymph node in the pelvis

M Categories

The M category stands for metastasis, or whether or not the cancer has spread to distant organs.

• MX means that tests to detect distant spread have not been done.
• M0 means that the cancer has not spread beyond the nodes in the pelvis.
• M1 means the cancer has spread to distant sites.
  • M1a means the cancer has spread to distant lymph nodes.
  • M1b means the cancer has spread to bone(s).
  • M1c means the cancer has spread to other organs such as lungs, liver, or brain.

Although in this AJCC staging system, the T, N, M stages are to be combined into a single Roman numeral I–IV, this is not often needed for prostate cancer because the stages follow the T stage. Stage I = T1, Stage II = T2, Stage III = T3, and Stage IV includes T4 and spread to lymph nodes or distant sites.

EARLY DETECTION

TYPES OF TREATMENT

For more information on these treatment guidelines, or on cancer in general, call the NCCN at 1-888-909-NCCN or the American Cancer Society at 1-800-ACS-2345. Or you can visit these organizations’ web sites at www.cancer.org (ACS) and www.nccn.org (NCCN).

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