Prostate cancer
Prostate cancer is a disease is which the cells of the prostate become abnormal and start to grow uncontrollably, forming tumors. It is the most common cancer among men in the United States,and is the second leading cause ofcancer deaths.
The prostate, testicles, and seminal vesicles are the major male sex glands.These three glands together secrete the fluid that makes up semen. The prostate is about the size of a walnut and lies just behind the urinary bladder. Atumor in the prostate interferes with proper control of the bladder and normal sexual functioning. Often, the first symptom of prostate cancer to developis difficulty in urinating.
The cause of prostate cancer is not known, however, it is found mainly in menover the age of 55. 80% of the prostate cancer cases occur in men over the age of 65. Hence, age appears to be a risk factor for prostate cancer. Race may be another contributing factor, because African-Americans have the highestrate of prostate cancer in the world.
A family history of prostate cancer may put a man at a higher risk for getting this disease. In addition, there is some evidence to suggest that a diet high in fat increases the risk of prostate cancer.
Frequently, prostate cancer has no symptoms, and the disease is diagnosed when the patient goes for a routine screening examination. However, occasionally, when the tumor is big or the cancer has spread to the nearby tissues, the following symptoms may be seen:
- Weak or interrupted flow of the urine
- Frequent urination (especially at night)
- Difficulty startingurination
- Inability to urinate
- Pain or burning sensation when urinating
- Blood in the urine
- Persistent pain in lower back, hips, or thighs (bone pain)
- Painful ejaculation.
In order to diagnose the disease doctor may conduct a digital rectal examination (DRE) to feel for any lumps in the prostate. The rectum lies just behindthe prostate gland, and a majority of prostate tumors begin in the posteriorregion of the prostate. If the doctor does detect an abnormality, he or she may order more tests in order to confirm these findings.
Blood tests are used to measure the amounts of certain protein markers, suchas prostate-specific antigen (PSA), found circulating in the blood. A technique known as "transrectal ultrasound" can also be used to detect tumors. In this test, a small probe is placed in the rectum, and sound waves are releasedfrom the probe. These sound waves bounce off the prostate tissue and an imageis created. Since normal prostate tissue and prostate tumors reflect the sound waves differently, the test can detect tumors quite efficiently. If canceris suspected, the doctor will remove a small piece of prostate tissue with ahollow needle. This is then checked under the microscope for the presence ofcancerous cells. Prostate biopsy is the most definitive diagnostic tool forprostate cancer.
The doctor and the patient will decide on the treatment mode after considering many factors. For example, the patient's age, the stage of the tumor, his general health, and the presence of any co-existing illnesses have to be considered. In addition, the patient's personal preferences and the risks and benefits of each treatment protocol are also taken into account before any decision is made.
For early stage prostate cancer, surgery is the best option and the most common one. Radical prostatectomy involves complete removal of the prostate. Because the seminal vesicles (the gland where the sperm is made) are removed along with the prostate, infertility is a side effect of this type of surgery. Ina different surgical method, known as the transurethral resection procedureor TURP, only the cancerous portion of the prostate is removed, by using a small wire loop that is introduced into the prostate through the urethra. Thistechnique is most often used in men who cannot have a radical prostatectomy due to age or other illness, and it is rarely recommended.
Radiation therapy involves the use of high-energy x rays to kill cancer cellsor to shrink tumors. It can be used instead of surgery for early stage cancer. Hormone therapy is commonly used when the cancer is in an advanced stage and has spread to other parts of the body. Prostate cells need the male hormone testosterone to grow. Decreasing the levels of this hormone, or inhibitingits activity, will cause the cancer to shrink. Hormone levels can be decreased in several ways.
Drugs (such as LHRH agonists or anti-androgens) that bind to the male hormonetestosterone and block its activity can be given. Another method tricks thebody by administering the female hormone estrogen. When this is given, the body senses the presence of a sex hormone and stops making the male hormone testosterone. Alternatively, a surgical procedure which involves the complete removal of the testicles can be done. However, there are some unpleasant side effects to hormone therapy.
Chemotherapy is the use of drugs to kill cancer cells. The drugs can either be taken as a pill or injected into the body through a needle that is insertedinto a blood vessel. Chemotherapy is sometimes used to treat prostate cancerthat has recurred after other treatment.
Due to early detection and better screening methods, nearly 60% of the tumorsare diagnosed while they are still confined to the prostate gland. The five-year survival rate for early stage cancers is almost 99%.
Because the cause of the cancer is not known, there is no definite way to prevent prostate cancer. However, the American Cancer Society (ACS) recommends that all men over age 40 have an annual rectal exam and that men have an annual PSA test beginning at age 50. African-American men and men with a family history of prostate cancer, who have a higher than average risk, should begin annual PSA testing even earlier, starting at age 45. A low fat diet may slow the progression of prostate cancer.
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