What are the normal values and recommendations for Prostate-Specific Antigen (PSA) screening?

From the Guidelines

Men aged 55-69 should have an individualized discussion with their healthcare provider about the benefits and risks of prostate-specific antigen (PSA) screening before deciding to undergo testing, with a normal PSA value generally considered to be below 4.0 ng/mL. The decision to screen for prostate cancer should be based on a shared decision-making approach, taking into account the patient's general health, life expectancy, and preferences 1. For men in their 40s, values below 2.5 ng/mL are typically considered normal, while for men in their 50s, values below 3.5 ng/mL are often acceptable. Men aged 70 and older or those with less than 10-15 years life expectancy are usually not recommended for routine PSA screening due to limited benefit. If screening is pursued, it's typically done every 1-2 years rather than annually. PSA levels can be elevated not only by prostate cancer but also by benign conditions like prostate enlargement, inflammation, or recent ejaculation, which is why a single elevated result should be confirmed before proceeding to more invasive testing. The PSA test measures a protein produced by both normal and malignant prostate cells, and while higher levels may indicate cancer, the test cannot distinguish between aggressive cancers that need treatment and slow-growing cancers that might never cause symptoms.

Some key points to consider when discussing PSA screening with patients include:

• The potential benefits and harms of screening, including the risk of false-positive results, overdiagnosis, and overtreatment 1
• The patient's individual risk factors for prostate cancer, such as family history and age 1
• The importance of shared decision-making and patient preferences in determining whether to undergo screening 1
• The potential consequences of screening, including the need for further testing and treatment if cancer is detected 1

It's also important to note that the evidence on PSA screening is not universally agreed upon, with different guidelines and studies reaching different conclusions about the benefits and harms of screening 1. However, the most recent and highest-quality evidence suggests that individualized decision-making and shared decision-making approaches are essential in determining whether to undergo PSA screening 1.

From the Research

PSA Screening Normal Values

• The normal values for PSA screening vary, but a study published in 2 found that the median baseline PSA was 1.19 ng/mL, and the median percent free PSA was 18%.
• Another study published in 3 found that biological variation for total and free PSA was 14.7 and 14.0%, respectively.

Recommendations for PSA Screening

• A study published in 2 found that the addition of percent free PSA to total PSA in men with baseline PSA ≥2 ng/mL improved prediction of clinically significant prostate cancer and fatal prostate cancer.
• The same study found that percent free PSA improved prediction of clinically significant prostate cancer and fatal prostate cancer for all race groups.
• A study published in 4 found that incorporating PSA velocity into a multivariable model for prostate cancer detection led to a very small increase in area under the curve, and that biopsying men with high PSA velocity but no other indication would lead to a large number of additional biopsies.
• A study published in 5 found that quadrennial screening between the ages of 55 and 69 years with active surveillance for men with low-risk cancers resulted in an incremental cost per quality-adjusted life-year of $51,918 or $69,380, respectively.
• A study published in 6 found that digital rectal examination (DRE) was not a useful screening test for prostate cancer at serum PSA level 3.0-3.9 ng/ml, while the results regarding free/total PSA determination were more encouraging.

Factors Affecting PSA Levels

• A study published in 3 found that digital rectal examination causes a modest increase in total and percentage of free PSA, and that prostate needle biopsy causes more dramatic increases in both forms of PSA.
• The same study found that free PSA is preferentially released into the serum after prostatic manipulation and appears to be cleared more rapidly than complexed PSA.