Addressing PSA Specificity Webinar

Prostate specific antigen (PSA) tests are utilized by a wide variety of healthcare professionals – including family physicians, urologists and oncologists – to aid in the detection, monitoring and management of prostate cancer. Different types of PSA tests can be used to guide decision-making at different stages of the disease. Physicians will often employ a test that measures total serum PSA for frontline risk assessment. A Free PSA (fPSA) test may be ordered when a patient exhibits a moderately elevated total PSA.

• It is a walnut-sized gland only found in men
• It is located below the bladder and in front of the rectum
• The urethra, which carries the urine, runs through the prostate
• It also contains the cells that make semen

• Prostate cancer is cancer that begins in the prostate gland
• Most prostate cancers are small, slow growing tumors
• Studies show that as many as 9 out of 10 men will have prostate cancer by age 80; however, the majority of these cancers will not be life threatening

• Prostate specific antigen (PSA) is a protease produced primarily by the prostate gland
• It is mostly found in semen but can also be found in bloodstream
• PSA exists as Free PSA (fPSA) and PSA bound to protease inhibitors, which is known as Complexed PSA (cPSA)

• A PSA test is the classical screening method that aids in the detection of prostate cancer
• It is a simple blood test that measures the amount of PSA in the bloodstream
• It is clinically accepted by the NCCN, NACB and EGTM for both detection and monitoring
• It is used in conjunction with a digital rectal examination (DRE)

• As PSA levels increase the chance of a patient having prostate cancer increases
• PSA testing in conjunction with a DRE is FDA-approved in men over 50 years. If a patient is considered high risk due to family history or ethnicity, testing is recommended at age 45
• PSA testing can be used in managing prostate cancer

• Under 4.0 ng/mL is currently considered normal
• Between 4.0 and 10 ng/mL is considered moderately elevated (“the gray zone”). A fPSA test can be used to help distinguish prostate cancer from benign prostastic hyperplasia when total PSA results are in the gray zone
• Above 10 ng/mL is considered elevated

• fPSA is used in conjunction with total PSA to determine a percentage of fPSA value. The higher the percentage of fPSA, the more likely the patient has a non-cancerous disease such as benign prostatic hyperplasia or prostatitis
• Measuring cPSA is more specific for prostate cancer than measuring total PSA alone ^1-4
• cPSA, like total PSA, is recommended by the NCCN as a frontline screening test

• A biopsy is taken to determine if cancer cells are present
• The biopsy will be graded using the Gleason scoring system, which compares the patient’s biopsy to normal prostate cells
• The most prevalent pattern and the second most prevalent pattern are graded on a scale from 1 to 5 and then added to create a total score between 2 and 10. Aggressiveness of cancer increases with the grade. In general, total scores between 2 and 4 are considered less aggressive, between 5 and 7 are considered moderately aggressive and between 8 and 10 are considered the most aggressive
• Imaging tests, such as bone scan, CT scan and MRI may also be employed to determine if cancer has spread

• Benign prostatic hyperplasia (BPH) — enlargement of the prostate gland. BPH can cause varying degrees of urinary obstruction by constricting the urethra
• Prostatitis — inflammation of the prostate gland that can cause frequent or urgent need for urination accompanied by pain or burning
• Elevated PSA values can be due to BPH or prostatitis
• Both conditions are treatable and are not known to cause prostate cancer

^{1: Parsons JK, Brawer MK, Cheli CD, Partin AW, Djavan R. Complexed prostate specific antigen (PSA) reduces unnecessary prostate biopsies in the 2.6-4.0 ng/mL range of total PSA. BJU Int. 2004 Jul;94(1):47-50.1
2: Lilja, et al. Significance of different molecular forms of serum PSA. Urol C Clin North Am 1993; 20:681:686.
3: Lilja H, Christtensson A, Matikainen M-T, et al. Prostate-specific antigen occurs predominantly in complex alpha-1-antichymotrypsin. Clin Chem 1991 ; 7 :1618-25.
4: Stenman UH, Leinonen J, Alfthan H, et al. A complex between prostate-specific antigen and alpha-1-antichymotrypsin is the major form of prostate-specific antigen in serum of patients with prostatic cancer: Assay of the complex improves clinical sensitivity for cancer. Cancer Res 1991; 51: 222-6.}