PSA means Prostate Specific Antigen. It is an enzyme secreted mainly by the prostate and is involved in liquefaction of the semen. PSA has been used for over two decades to screen and follow PSA post- treatment of prostate cancer. PSA drawn from the bloodstream and the digital rectal exam are the two methods used for screening prostate cancer. The AUA, American Urological Association, recommends a baseline PSA begin at age 40. Screening for prostate cancer should also start at age 40 for men with a positive family history of a first -degree relative or African- American heritage. Both are associated with an increased risk of prostate cancer incidence. An example of a first-degree relative would be a father diagnosed with prostate cancer. In addition, the person being screened should have a life expectancy of 10 years or more. Other men with an average risk, should start screening at age 50.
The question of over-diagnosis and over-treatment of prostate cancer by urologists has been questioned in some reports. However, it should be taken into consideration that one in six American-men are diagnosed with prostate cancer (Int J Cancer 2005; 113: 312). Moreover, ten percent of all cancer mortality is attributed to prostate cancer (Jemal. CA Cancer J Clin 2005; 55: 10-30). Hence, diagnosing prostate cancer and early detection are important factors to better quality of life for patients, if not longevity.
The data has been controversial on whether or not we are saving lives with prostate cancer screening. One trial reports no decrease in mortality benefit (N Engl J Med 2009; 360: 1310-9). However, another, large trial reports a 20% decrease in prostate cancer mortality rates from PSA-based screening( N Eng J Med 2009;360:1320-8). Both studies point to over-diagnosis and over-treatment of prostate cancer.
PSA and digital rectal examination are currently used to screen for prostate cancer. It allows for early detection which may result in a better quality of life and longevity. A patient should be well informed. The possibility of over-diagnosis and treatment should be discussed as well as the benefits.Tags: American Urological Association (AUA), Prostate Cancer, Prostate Specific Antigen, PSA