What is Prostate Cancer?
The prostate, part of the male reproductive system, is a walnut-sized gland that makes the seminal fluid for carrying sperm. It is located behind the base of the penis, in front of the rectum, and below the bladder. It surrounds the urethra, the tube-like channel that carries urine and semen through the penis.
Prostate cancer is the most common cancer (other than skin cancer) diagnosed in men in the U.S. Cancer begins when healthy cells in the prostate change and grow out of control. They can form a tumor, which often first appears in the outer area of the prostate, near the rectum.
Early-stage prostate cancer usually has no symptoms, but they can show up later. Symptoms include:
- Having to pee more often, especially at night,
- Straining to empty your bladder,
- Blood in your urine or seminal fluid,
- New onset of erectile dysfunction,
- Discomfort or pain when sitting (caused by an enlarged prostate),
- (Less commonly) pain or burning during urination.
Other symptoms can occur if cancer has spread beyond the prostate gland.
Some prostate cancers grow very slowly and may not cause symptoms or problems for years or ever. Even advanced prostate cancer can be managed with good health and quality of life for a long time. But other prostate cancers are more aggressive. Monitoring for tumor growth is an important part of managing this disease. Screening is done with a blood test that measures prostate-specific antigen (PSA).
What is PSA Test?
The PSA blood test measures levels of prostate-specific antigen, or PSA, which is released into the bloodstream from cells in the prostate. Elevated PSA levels can indicate cancer. Ejaculation can temporarily increase PSA, so avoid it before any PSA test. (Conversely, the PSA decreases by 50% in men who take dutasteride or finasteride. For this reason, their PSA readings should be doubled when assessing test results.)
Until about 2008, some doctors and professional organizations recommended PSA screening every year for men beginning at age 50, and beginning at age 40 or 45 for men at higher risk of getting prostate cancer. Men at higher risk include African-American men and men whose father or brother had prostate cancer. Most organizations now recommend that you first discuss the risks and benefits of PSA screening with your doctor.
Currently, Medicare provides coverage for an annual PSA test for all Medicare-eligible men age 50 and older. Many private insurers cover PSA screening as well.
What is PSA Velocity?
Elevated PSA readings could indicate the presence of cancer, but another important measurement is how fast those readings increase. The speed of increase is called PSA velocity. Studies show that if a PSA velocity is over 0.35 ng/mL (nanograms per milliliter) per year, and if the patient has prostate cancer, it is more likely to be an aggressive cancer.
What are the major risk factors for prostate cancer?
- Family history. A man is two to three times more likely to be diagnosed with prostate cancer if his father, brother, or son has had it. The more relatives diagnosed with prostate cancer, the higher the risk.
- Race and ethnicity. Prostate cancer is more prevalent in African American men, who are also more than twice as likely to die from the disease as men of other races and ethnicities. They can also develop prostate cancer at an earlier age and to have more aggressive tumors.
What are other risk factors for prostate cancer?
- Age. Prostate cancer is rare in men younger than 40, but the risk of prostate cancer rises rapidly after age 50. More than 80 percent of prostate cancers are diagnosed in men age 65 or older.
- Diet/obesity. Men who eat a lot of red meat or high-fat dairy products appear to have a slightly higher chance of getting prostate cancer. These men also tend to eat fewer fruits and vegetables. Doctors aren’t sure which of these factors raises the risk. Some studies have found that obese men have a lower risk of getting a low-grade (less dangerous) form of the disease, but a higher risk of getting more aggressive prostate cancer.
- Gene changes. Inherited gene changes probably account for only a small percentage of prostate cancers. Hereditary breast and ovarian cancer (HBOC) syndrome involves mutations in the BRCA1 and BRCA2 genes and may increase prostate cancer risk. Men with Lynch syndrome (also called hereditary non-polyposis colorectal cancer, or HNPCC) also have an increased prostate cancer risk.
- Agent Orange exposure. The U.S. Department of Veterans Affairs lists prostate cancer as a disease associated with exposure to Agent Orange, a chemical used during the Vietnam War. The Institute of Medicine considers there to be “limited/suggestive evidence” of a link between Agent Orange exposure and prostate cancer.