Prostate Cancer Screening
What is Prostate Cancer?
Prostate cancer is a disease in which malignant (cancer) cells form in the tissues of the prostate.
The goal of screening for prostate cancer is to find cancers that may be at high risk for spreading if left untreated, and to find them before they spread. Most men diagnosed with prostate cancer do not die of it.
Facts and Figures
In Missouri, prostate cancer has the fifth highest incidence and mortality rate among cancers. It is most common among older men. About one out of nine men will be diagnosed with prostate cancer in this state.
While routine screening for prostate cancer among people with an average risk of developing the disease is not recommended, the United States Preventive Services Task Force (USPSTF) does recommend that men who are 55 to 69 years old should speak with a doctor and make a personal decision about whether or not to be screened for prostate cancer. The USPSTF also recommends that men speak with a doctor about potential benefits of prostate cancer screening as well as any potential harms of testing and treatment. Finally, the USPSTF recommends that men aged 70 and older should not be routinely screened for prostate cancer.
These recommendations apply to men who are at both an average and elevated risk for prostate cancer, have no symptoms, and have never received a prostate cancer diagnosis.
Screening for prostate cancer begins with a blood test called a prostate specific antigen or PSA test. This test measures the level of PSA in the blood. PSA is a substance made by the prostate. The levels of PSA in the blood can be higher in men who have prostate cancer. The PSA level may also be elevated by other conditions that affect the prostate.
As a rule, the higher the PSA level in the blood, the more likely a prostate problem is present, but many factors, such as age and race, can affect PSA levels. Some prostate glands make more PSA than others. PSA levels can also be affected by certain medical procedures, medications, a prostate infection or an enlarged prostate. It is important for a doctor to interpret PSA test results for abnormalities. If the PSA test is abnormal, the doctor may recommend a biopsy to find out if prostate cancer is present.
Overdiagnosis of Prostate Cancer
While screening for prostate cancer can find cancer in men with no symptoms of cancer, it can also find prostate cancer in some men who might never develop cancer symptoms. Most prostate cancers grow slowly, or not at all. Treatment of men who would not have had symptoms or died from prostate cancer can cause complications from treatment without benefitting from it. This is called overdiagnosis.
Overdiagnosis can cause men with early prostate cancer to undergo cancer treatment procedures like surgery and radiation therapy that may not be needed. These treatments can cause a number of complications:
- urinary incontinence (bladder leakage);
- erectile dysfunction (impotence); and
- bowel problems, such as an accidental leakage of bowel movement or a sudden and uncontrollable urge to have a bowel movement.
Prostate Cancer Prevention
Prostate cancer is the most common cancer among men in Missouri.
The most common risk factor for prostate cancer is age. The older a man is, the greater his chance of getting prostate cancer. African-American men and men with a family history of prostate cancer are also at an increased risk for developing the disease. These risk factors (age, race, gender, and family history) cannot be controlled and there is no sure way to prevent prostate cancer; however, there are actions that can be taken to reduce risk of developing this disease.
Get Enough Folate
Folate is a kind of vitamin B that occurs naturally in some foods, such as green vegetables, beans and orange juice. Folic acid is a man-made form of folate that is found in vitamin supplements and fortified foods, such as whole-grain breads and cereals. A 10-year study showed that the risk of prostate cancer was lower in men who were getting enough folate in their diets. However, the risk of prostate cancer was increased in men who took as little as 1 milligram (mg) of folic acid supplement.
Take Finasteride and Dutasteride
Finasteride and dutasteride are drugs used to lower the amount of male sex hormones made by the body. These drugs block the enzyme that changes testosterone into dihydrotestosterone (DHT). Higher than normal levels of DHT may play a part in developing prostate cancer. Taking finasteride or dutasteride has been shown to lower the risk for prostate cancer, but it is not known if these drugs lower the risk of death from prostate cancer.
Limit Intake of Dairy and Calcium
A diet high in dairy foods and calcium may cause a small increase in the risk of prostate cancer.
Avoid Vitamin E Supplements
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) found that vitamin E taken alone increased the risk of prostate cancer. The risk continued even after the men stopped taking vitamin E.