Epidemiology

What is it?

Prostate cancer is a malignant tumor of the prostate gland, a walnut-sized organ located in front of the rectum and right below the bladder. The function of the prostate gland is to produce part of seminal fluid, the solution that carries sperm.

Prostate cancer is the most common type of cancer found in American men, other than nonmelanoma skin cancer. It is second only to lung cancer as the most common cause of male cancer-related death. The American Cancer Society estimates that in 2009, approximately 192,280 new cases were diagnosed in the United States and 27,360 men died from the disease.

Like all cancers, prostate cancer is a disease of uncontrolled cell growth. Cells become cancerous when they divide unpredictably and form tumors. As tumors grow, they squeeze surrounding healthy tissue and use oxygen that would normally be used by healthy cells. They also secrete protein signals that initiate the formation of new blood vessels for the tumor. As a prostate tumor grows, it may spread to the entire prostate gland or to lymph nodes, other organs, or bone.

While there is no known cause for prostate cancer, risk factors include:

• Age
  The risk for prostate cancer increases with age, with men over age 65 at highest risk.
  
  
• Race
  African American men are more than twice as likely to be diagnosed with prostate cancer as Caucasian Americans.
  
  
• Family history
  Studies show that a man's risk for prostate cancer increases if a close male relative (father, brother, uncle, grandfather) has the disease.
  
  
• Diet
  Some studies suggest that a high-fat diet, particularly red meat and dairy products, appears to simulate the growth of prostate cancer cells.

Most early prostate cancers cause no symptoms. When symptoms are present, they may include changes in urination flow, frequency or urgency; erectile difficulties; or pelvic, hip, or back pain. These symptoms may also occur in other diseases unrelated to prostate cancer.

The prostate-specific antigen (PSA) blood test and the digital rectal examination (DRE) are the most effective tests currently available for the early detection of prostate cancer. As part of an annual checkup, the American Cancer Society recommends the DRE and PSA test for:

• men 50 and older with a life expectancy of at least 10 years
• younger men who are at increased risk for prostate cancer, including men with a family history of the disease and African American men.

More information:

• The Prostate Gland