Prostate cancer involves a malignant tumor growth within the prostate gland.

Causes, incidence, and risk factors

The cause of prostate cancer is unknown, although some studies have shown a relationship between high dietary fat intake and increased testosterone levels. When testosterone levels are lowered either by surgical removal of the testicles (castration, orchiectomy) or by medication, prostate cancer can regress. There is no known association with benign prostatic hyperplasia (BPH).

Prostate cancer is the third most common cause of death from cancer in men of all ages and is the most common cause of death from cancer in men over 75 years old. Prostate cancer is rarely found in men younger than 40.

Men at higher risk include black men older than 60, farmers, tire plant workers, painters, and men exposed to cadmium. The lowest incidence occurs in Japanese men and vegetarians.

Prostate cancers are classified or staged based on their aggressiveness and how different they are from the surrounding prostate tissue. There are several different ways to stage tumors, a common one being the A-B-C-D staging system, also known as the Whitmore-Jewett system:

A: Tumor is not palpable (not felt on physical examination), and is usually detected by accident after prostate surgery done for other reasons.
B: Tumor is confined to the prostate and usually detected by physical examination or PSA testing.
C: Tumor extends beyond the prostate capsule without spread to lymph nodes.
D: Cancer has spread (metastasized) to regional lymph nodes or other parts of the body (bone and lungs, for example).

This system also contains several substages.

Symptoms

With the advent of PSA testing, most prostate cancers are now found before they cause symptoms. Additionally, while most of the symptoms listed below can be associated with prostate cancer, they are more likely to be associated with non-cancerous conditions.

-Urinary hesitancy (delayed or slowed start of urinary stream)
-Urinary dribbling, especially immediately after urinating
-Urinary retention
-Pain with urination
-Pain with ejaculation
-Lower back pain
-Pain with bowel movement
-Additional symptoms that may be associated with this disease:
- Excessive urination at night
-Incontinence
-Bone pain or tenderness
-Hematuria (blood in the urine)
-Abdominal pain
-Anemia
-Unintentional weight loss
-Lethargy
-Signs and tests

A rectal exam often reveals the hard, irregular surface of an enlarged prostate.

Testing considerations:

-PSA (prostate specific antigen, a blood test) may be elevated, although other conditions such as BPH can cause the PSA to rise.
-Free PSA may be more specific in differentiating BPH from prostate cancer.
-Urinalysis may reveal blood in the urine.
-Urine or prostatic fluid cytology may reveal atypical cells.
-A prostate biopsy confirms the diagnosis.
-CT scans may be performed to rule out metastasis (spread of the cancer).
-A bone scan may be performed to rule out metastasis.
-Chest x-ray may be performed to rule out metastasis.
-A newer test called AMACR is more sensitive for determining the presence of prostate cancer than the PSA test and may soon be more widely used to diagnose disease.