Prostate cancer is a disease in which malignant (cancer cells) form in the tissues of the prostate. The prostate is a gland in the male reproductive system located in the pelvis just below the bladder and in front of the rectum. The size of the gland varies from patient to patient but is typically the size of a walnut. It surrounds the urethra (the tube that empties urine from the bladder), and produces fluid that makes up part of the semen.
According to the American Cancer Society, prostate cancer is the first most common form of cancer affecting men in the United States, with an estimated 233,000 men diagnosed in 2014. About 1 in 7 men in the United States will be diagnosed with prostate cancer in their lifetime. It is the second leading cause of cancer death in the United States, with an estimated 27,050 deaths from prostate cancer in 2007. This represents approximately 2.71% of male deaths (from all causes) in the United States annually.
There are no noticeable symptoms of prostate cancer while it is still in the early stages. In order to find prostate cancer in its most treatable form, it must be caught before symptoms appear. In more advanced stages, symptoms may include difficult or frequent urination, blood in the urine or bone pain.
- The risk of prostate cancer increases with age. Prostate cancer is rare for men under the age of 40; and 97% occur in men over age 50.
- Men with a father or brother with prostate cancer are twice as likely to get the disease. Men with three relatives diagnosed with prostate cancer are even more likely to get it.
- African American men have a 60% higher risk of getting prostate cancer than Caucasian men, and are at twice the risk of dying from it.
- Carribean men are also at high risk.
- Hispanic men have a risk of getting prostate cancer similar to the general population, but rates of death due to the disease have not declined over recent years as they have for Caucasians and African American men.
- Veterans of Asian Theaters (Vietnam and Korea) who were exposed to Agent Orange are at increased risk.
- Obese men – those with a body mass index of over 32.5 – are 33% more likely to die from prostate cancer if diagnosed.
- LYNCH syndrome and BRCA2 — inherited conditions which increase the risk of getting prostate cancer.
Prostate Cancer Screening consists of two examinations:
- A blood test that measures levels of Prostate Specific Antigen or PSA.
- A physical examination of the prostate, the Digital Rectal Exam or DRE. A DRE is a quick and painless physical exam where the doctor feels for bumps or abnormalities on the surface of your prostate which may represent tumor growth. The word digital refers to use of a finger, not a computer.
If a bump or abnormality is found, or if the PSA level is inordinately high, a biopsy is needed to determine whether prostate cancer exists.
Prostate Cancer Screening Considerations:
Annual screening should start at age 50 for the general population
Men with 1 risk factor should start annual screening at age 45.
Men with more than 1 risk factor should start screening at age 40.
Some men choose to have a baseline examination and blood test between the ages of 35 and 40.
Both the absolute PSA level and the rate of rise over time are important in predicting the presence of prostate cancer.
The two screening tests (DRE and PSA level) are not perfect, but together they detect about 85% of patients with prostate cancer.
Ancillary Tests for Prostate Cancer Screening:
- PSA free to total ratio — for those patients with total PSA levels in the 4 to 10 range, a low free to total ratio is associated with a higher chance of having prostate cancer.
- PSA density — this is measured as a ratio of PSA level to prostate volume. A high PSA density is associated with a higher chance of having prostate cancer.
- PCA3 test– demonstrates the presence of DNA sequences typically associated with prostate cancer. The higher the PCA3 score, the higher the chance of having prostate cancer (and the higher the chance of having high grade disease).
- 4K test — a multi-parameter test that predicts the presence of an aggressive form of prostate cancer. The higher the score, the more likely an aggressive form of prostate cancer exists.
- MDx test — this is an “epigenetic” test that examines negative prostate tissue biopsies for the presence of certain patterns typically seen in prostate cancer. This test is sometimes useful to see if a prostate biopsy recently done is truly negative. A positive MDx result is highly suggestive of the presence of prostate cancer.
Ancillary Tests to Determine Whether or Not to Treat Prostate Cancer:
- Prolaris — this is a multi-parametric test that examines positive prostate tissue biopsies for the presence of certain patterns typically seen in aggressive forms of prostate cancer. It predicts the likelihood of death from prostate cancer within 10 years.
- OncotypeDX — this is a multi-parametric test that examines positive prostate tissue biopsies for the presence of certain patterns typically seen in aggressive forms of prostate cancer. Higher OncotypeDX scores indicate higher likelihood of death from disease.
Prostate Cancer Prevention:
There is evidence to suggest that the use of Proscar (a 5-alpha reductase inhibitor) results in a reduced risk of prostate cancer. The first assessment of this drug in the Prostate Cancer Prevention Trial indicated that while cancer risk is reduced, those who developed prostate cancer tended toward a more aggressive form of it. This data was reanalyzed (in Cancer Prevention Research ), and it’s now thought that there is not this greater proclivity towards a more aggressive form of cancer, only total risk reduction.
A vaccine against prostate cancer has long been in research and development, though no product has been made available yet.
Adopting a healthy lifestyle consisting of regular exercise and limiting consumption of saturated fat found in red meat and dairy products may lower your risk of cancer. This may also improve your cardiovascular health, overall quality of life, and longevity. Much attention has been given to diets rich in Vitamin E, Selenium, soy, green tea, and tomatoes, though there is no conclusive evidence that these nutrients lower prostate cancer risk.