Prostate Cancer
The prostate is a chestnut-shaped gland that sits at the base of the bladder, in front of the rectum and surrounding the urethra.
What is it?
Prostate cancer is the growth of malignant cells in the prostate, a walnut-size gland located just below the bladder in men, which produces about 30 percent of the fluid portion of semen. Prostate cancer is common:Men have a lifetime chance of between one in 10 and one in 13 of developing the disease. It is the most commonly diagnosed male cancer and the second leading cause of male cancer deaths. Indeed, autopsy studies have shown that 60 to 70 percent of all men who reach the age of 80 have at least some microscopic evidence of prostate cancer. Symptoms do not occur until the cancer has spread beyond the prostate, highlighting the importance of regular checkups. Because prostate cancer tends to grow very slowly and takes years to spread, immediate and aggressive treatment may not be advised in older men. For such patients a diagnosis of prostate cancer may warrant a strategy of "watchful waiting." This involves regular examinations and blood tests, but treatment is undertaken only if evidence indicates tumor growth. The specific treatment plan depends upon a number of factors: the patient's age, the characteristics of the cancerous cells, the size of the tumor, whether cancer appears to have spread to other sites, and the risk of complications. Prostate cancer may be cured by removing the prostate gland before the cancer has spread. However, much controversy prevails about when to advise surgery because it is not possible to predict which cancers will spread and which will not. There is no cure once the cancer has spread beyond the prostate. In some cases though, prostate cancer never spreads, and in general, the outlook is good when the cancer is detected early.
What Causes It?
- The cause of prostate cancer is unknown, but age, family history, and race are the strongest risk factors.
- Age: The incidence of prostate cancer (rate of newly diagnosed cancer) increases faster with age than any other form of cancer.
- Family history: A family history of prostate cancer and early age at onset (under age 55) within a family increase the risk that a male will develop the disease.
- Race: African Americans have a one-and-a-half times greater incidence of prostate cancer than whites.
- The role of factors such as male hormones, dietary fat, and environmental toxins is not clear.
Prevention
- Men over age 50 should have regular digital rectal examinations (examination of the prostate with a gloved finger) and measurements of PSA (see Diagnosis) to aid in early detection and treatment.Men at high risk should begin testing between 40 and 45.
Diagnosis
- Patient history and physical examination, including a digital rectal examination.
- Blood tests. The prostate specific antigen (PSA) blood test is the most useful test for early detection. PSA, an enzyme secreted by the cells lining the prostate, functions to liquefy semen after ejaculation. Normally, little PSA enters the blood, but prostate cancer tends to boost levels of PSA in the bloodstream. However, since nonmalignant abnormalities such as benign hyperplasia (prostate enlargement) and prostatitis may also cause increased blood levels of PSA, other tests are necessary to confirm the diagnosis. (See Benign Prostatic Hyperplasia or Prostatitis for more information.)
- Multiple biopsies of the prostate are necessary to confirm the diagnosis. Transrectal ultrasonography (ultrasound scan with a rectal probe) allows visual imaging of the prostate and accurate placement of biopsy needles to obtain tissue samples. Small tissue samples are obtained with a needle inserted into the prostate through the rectum, guided by ultrasound.
How to Treat It
- Because prostate cancer tends to grow very slowly, a common management strategy is watchful waiting, which involves regular physical examinations and measurements of PSA to monitor the progress of the tumor, with more aggressive treatment advised when warranted.Watchful waiting is often recommended for men in their 70s and 80s who are thought to have localized cancer.
- Total surgical removal of the prostate gland (radical prostatectomy) is the most common treatment; it usually includes removal of nearby lymph nodes. A better understanding of the location of structures important for erectile function and urinary control have greatly reduced the risk of impotence and incontinence. Surgery is generally recommended for men in their 50s and 60s.
- Radiation therapy to destroy cancerous cells may be recommended for somewhat older men or those who are unable to withstand surgery.
- In advanced cases in which the cancer has spread, surgical removal of the testicles (orchiectomy) or hormone therapy (which involves the administration of substances that block the release or function of male hormones) may slow the growth of prostate cancer and thus minimize or arrest the further spread of the cancer. Chemotherapy is used when hormonal therapy is unable to control tumor growth.
When to Call a Doctor
- Call a doctor if you experience difficult, painful, or unusually frequent urination.
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Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.