What Is Prostate Cancer?

The prostate, a walnut-sized gland of the male reproductive system, is located just below the bladder and in front of the rectum. The prostate's function is to produce a component of semen.

Most prostate cancer is latent, that is, it produces no symptoms, or is indolent, which means it's so slow-growing that it never becomes a serious threat to health. The causes of prostate cancer are not known but are presumed to be linked to hereditary factors and hormonal changes in men as they age. But some prostate cancers will produce symptoms, threaten health and/or require treatment.

Older men also may suffer from "enlarged prostate," a noncancerous condition in which the prostate gets bigger and blocks the urethra, causing difficulty urinating or impairing sexual functioning. This condition - called benign prostatic hyperplasia (BPH) - exhibits symptoms similar to prostate cancer and may require surgery.

How Common Is Prostate Cancer?

Cancer of the prostate is the second most common type of cancer in American men (behind skin cancer) and the second leading cause of cancer death in men (behind lung cancer). Prostate cancer is especially common in older men: A third of men over 50 have microscopic signs of prostate cancer, and at 75 more than half of men will have some cancerous cells in their prostate.

What's My Risk of Getting Prostate Cancer?

Studies have shown that men with any of the following characteristics may be at increased risk of developing prostate cancer:

  • Age 50 or older: Risk increases with age, and more than 70 percent of men diagnosed each year with prostate cancer are over 65.
  • African American: The incidence of prostate cancer is 60 percent higher in African American men than in Caucasian American men. The disease occurs at about the same frequency in Caucasian men and Hispanic men but less frequently in Asian men.
  • Family history of prostate cancer: The risk of prostate cancer is doubled if a father or brother had it. The repeat incidence of prostate cancer in the same family suggests a genetic cause.
  • Diet rich in red meat and dairy products, but low in fruits and vegetables: There is a slightly increased risk for men who eat a diet high in animal fats. Doctors are unsure if the fat is to blame or the lack of fruits and vegetables.
  • North American or northwest European nationality: For reasons that are unclear, prostate cancer is more common in North America and northwestern Europe than it is in Asia, Africa, Central America and South America.
  • Vasectomy: Some studies have suggested that men who have had a vasectomy have a slightly higher risk for prostate cancer, particularly those men who were younger than 35 at the time of the vasectomy.

What Are the Symptoms of Prostate Cancer?

Prostate cancer may never cause symptoms if it is latent or indolent. When symptoms do occur, the disease may be quite advanced. Symptoms of prostate cancer include:

  • Difficulty urinating or a weak urine flow
  • Frequent urination (particularly the need to get out of bed to urinate)
  • Painful urination; a burning sensation when urinating
  • Presence of blood in the urine or semen
  • Chronic pain in the back, hips or pelvis

How Is Prostate Cancer Diagnosed?

There are a number of techniques and tests used to diagnose prostate cancer. They include:

  • Digital rectal exam (DRE): a simple doctor's office exam in which the physician inserts a gloved finger into the rectum and feels the prostate through the rectal wall to check for lumps or abnormalities.
  • Prostate-specific antigen (PSA) test: a blood test to measure the level of PSA, which is a substance found at higher levels in the blood of men who have prostate cancer. However, PSA levels also may be elevated in men who have BPH or an infection or inflammation of the prostate.
  • Prostate biopsy: a doctor's office procedure in which the physician inserts needles into the prostate under local anesthesia, usually through the rectum wall, to draw tissue samples. The samples are later examined under a microscope by a pathologist to look for cancer cells.

How Will I Know the Stage and Severity of My Prostate Cancer?

If cancer cells are found, the cancer is graded by the pathologist using the 1 to 5 range defined by the Gleason System:

  • Grade 1: The cancer cells somewhat resemble normal prostate cells.
  • Grade 5: The cancer cells do not resemble normal prostate cells and are spread throughout the prostate.
  • Between the two extremes, grades 2 through 4 are assigned based on intermediate characteristics of the cancer cells.
  • If different areas of the prostate cancer have different Gleason ratings, the ratings are added together producing a "Gleason Sum." The Gleason Sum is also known as the Gleason Score, and it is a number between 2 and 10, where the higher the number the more aggressive the cancer and the worse the prognosis. If you are given a Gleason number of 5 or lower, it is important to ask whether it is the Gleason Grade (ranging from 1-5) or the Gleason Sum/Score (ranging from 2-10).

Pathologists may also identify "suspicious" prostate cells, that is, cells that are not clearly cancerous, but are not quite normal either. These are classified as prostatic intraepithelial neoplasia (PIN) and can be either low grade or high grade.

How Does Prostate Cancer Progress?

Prostate cancer usually progresses very slowly. The cancer is commonly found in autopsies of older men who died of other causes. But, in some instances, prostate cancer grows and spreads quickly. The progress of the cancer is marked by four stages:

  • Stage I: The cancer is localized to the prostate and is virtually undetectable; it cannot be felt during a digital rectal exam or seen by imaging. Cancer at this stage is usually only found during prostate surgery for other reasons.
  • Stage II: In this stage, the cancer is more advanced than Stage I but has not spread outside the prostate.
  • Stage III: The tumor has spread to the seminal vesicles - the tubes leading from the prostate - but it has not yet spread to the lymph nodes or elsewhere in the body.
  • Stage IV: This is the most serious stage, when the cancer has metastasized. In this stage, the cancer can be found in neighboring organs or sites, such as the bladder and rectum, or at sites far from the prostate, such as the liver or lungs. The cancer also may be found in the bones or in the lymph nodes.

How Is Prostate Cancer Treated?

The treatments for prostate cancer are many and varied. A patient and his family will often choose from among a variety of treatment and management strategies, including surgery, radiation therapy, hormone therapy, chemotherapy, or the option of not treating the cancer at all but simply watching it for signs of progression.

The choice of treatment depends on multiple factors, including stage and grade of the cancer, prospects for a successful cure with the treatment being considered, patient age and overall health, and the patient's willingness or unwillingness to tolerate treatment side effects. A patient should carefully weigh the benefits and drawbacks of each option and get a second opinion before committing to an approach.

Does Prostate Cancer or Its Treatment Cause Erectile Dysfunction or Urinary Incontinence?

Prostate cancer itself does not cause impotence, but it may lead to problems with urination that could result in incontinence for some men. However, both surgery and radiation treatments for prostate cancer are associated with impotence and incontinence. One study found that erectile dysfunction was a side effect of treatment for 80 percent of men who had either a radical prostatectomy or external beam radiation therapy. While the incontinence usually clears up within a year or so after treatment, erectile dysfunction can continue.

It's a good idea to ask your doctor about these and other side effects before you begin treatment for prostate cancer. Both incontinence and erectile dysfunction are treatable conditions, even for men who have had surgery or radiation therapy for prostate cancer, but the prospect of developing these conditions may affect your choice of treatment.

Where Can I Get Information on Living Well with Prostate Cancer?

Your doctor may be able to refer you to community resources and local prostate cancer support groups. In addition, the following Web sites and organizations offer research news and information and assistance for people living with prostate cancer: