Prostate cancer

Prostate cancer is a group of cancerous cells (a malignant tumor) that begins most often in the outer part of the prostate. It is the second most common type of cancer in men in the United States. Skin cancer is the most common. Of all the men who are diagnosed with cancer each year, more than one-fourth have prostate cancer.

Stages of prostate cancer

If cancer is found in the prostate, the doctor needs to know the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, what parts of the body are affected. The doctor may use various blood and imaging tests to learn the stage of the disease. Treatment decisions depend on these findings.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Prostate cancer staging is a complex process. The doctor may describe the stage using a Roman number (I-IV) or a capital letter (A-D). These are the main features of each stage:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Stage I or Stage A -- The cancer cannot be felt during a rectal exam. It may be found by accident when surgery is done for another reason, usually for BPH. There is no evidence that the cancer has spread outside the prostate.
• Stage II or Stage B -- The tumor involves more tissue within the prostate, it can be felt during a rectal exam, or it is found with a biopsy that is done because of a high PSA level. There is no evidence that the cancer has spread outside the prostate.
• Stage III or Stage C -- The cancer has spread outside the prostate to nearby tissues.
• Stage IV or Stage D -- The cancer has spread to lymph nodes or to other parts of the body.

The most common method of staging used among clinical doctors is the TNM staging system.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• T1: Clinically inapparent tumor not palpable nor visible by imaging
• T1a: Tumor incidental histologic finding in 5% or less of tissue resected (in prostatectomy)
• 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 prostate
• T2a: Tumor involves one-half of 1 lobe or less
• T2b: Tumor involves more than one-half of 1 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 (lymph nodes confined to the true pelvis)
• N1: Metastasis in regional lymph node(s)
• MX: Distant metastasis 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