Why check PSA?
Prostate cancer (PCa) is the most common cancer among men. Nearly 1 out of 7 men in the US will be diagnosed with PCa during their lifetime. Over 170,000 men are diagnosed with PCa annually and nearly 30,000 men die of the disease every year. Screening for PCa is performed by a digital rectal exam and blood test called PSA. With prostate cancer screening, we could detect potentially lethal cancers at an early stage and intervene with treatments to cure the disease.
How is prostate cancer screening done?
Your doctor will recommend annual screening. Digital rectal exam is performed to check for any abnormality in the prostate suspicious for PCa. A PSA blood test is done to assess for prostate cancer.
What is PSA?
It is a blood test that was first developed in 1979 by researchers at Roswell Park Cancer Institute in Buffalo, NY. It is a protein produced by the prostate gland, and is elevated in various conditions including PCa, enlarged prostate, urine infection, prostate infection or inflammation. Other activities that can temporarily increase PSA include sexual activity, or bicycle riding within 48 hours of getting the test. Please refrain from these activities for at least 2-3 days prior to your PSA blood test. Certain medications such as testosterone, finasteride, dutasteride can affect it.
What constitutes an abnormal PSA?
This depends on the age, prior PSA values, and patient risk factors. Additionally, a component of PSA called free PSA is also valuable in making this decision. Generally, a value of PSA over 2.6 (depending on age) is considered abnormal and a free PSA of lower than 25% is considered abnormal. While 80% of men with abnormal PSA have no cancer, only 6.2% of men with no cancer have abnormal PSA. In men with high risk, or younger age group, or with a serially rising PSA, even lower PSA levels are considered abnormal. A rapidly rising PSA, termed HIGH PSA VELOCITY is also an indicator of possible prostate cancer even if the total value is within the normal range. The PSA test is usually repeated by the urologist for confirmation if it is abnormal. With higher PSA values, the risk of harboring PCa increases.
What is the evidence for prostate screening?
A landmark European study demonstrated a 21% reduction in dying from PCa in their study population as early as 11 years from the time of starting screening. An estimated 570 men needed to be screened to diagnose 18 men to prevent 1 death from PCa. The current guidelines by the American urological association recommend screening men aged between 55 to 69 years after weighing the benefits and risks. For men aged 40-54 years and who are at high risk can also be offered PCa screening. Men with high risk include those with a family member(s) diagnosed with prostate or breast cancer, and African American men.