PSA Dynamics: Beyond the Static Number
Prostate-specific antigen, or PSA, is a protein produced by both normal and cancerous cells in the prostate glands of all men. For many years, PSA has served as a key marker in prostate cancer screening, but its role has become increasingly complex. Understanding PSA – what it is, what it can tell you, and what it can't – is crucial for men navigating their health. This blog post aims to demystify PSA, exploring its uses and the latest recommendations surrounding its use in prostate cancer detection.
PSA Misconceptions
Historically, men have believed that an elevated PSA level is an outright indicator of prostate cancer. An elevated PSA level is a possible indication of prostate cancer, but other non-cancerous conditions are associated with elevated PSA. These conditions include but are not limited to prostate infection, enlarged prostate, inflammatory problems of the prostate, generalized systemic diseases such as viral infections, and prostate stimulation from activities such as bike riding, prolonged sitting, and anal intercourse. Furthermore, some men naturally have higher PSA levels in their bloodstream without significant issues causing the elevation.
Further Investigation
When a patient presents to my office with an elevated PSA, it is crucial for me to distinguish between the possibility of cancer and other issues that can result in an elevated PSA. In essence, further investigation is required.
Factors and Tests for PSA Evaluation
PSA Velocity
A steady but overtime rise in a man's PSA of more than 0.7 ng/dl per year increases the concern for prostate cancer. Conversely, a rapid rise in PSA may indicate less cause for concern. Typically, a sudden and rapid rise in a man's PSA is due to prostate inflammation or infection.
Free to Total PSA Ratio
Some PSA proteins are attached to other proteins in the bloodstream, while some PSA proteins are free-floating without being attached to other proteins. Measuring how much PSA is free floating versus how much total PSA is present in the bloodstream is possible. The ratio of free PSA to total PSA expressed as a percentage can help determine the risk of prostate cancer. In general, the lower the ratio, the higher the risk of prostate cancer.
Liquid Biopsy Tests
Various methods are now available to test the urine of a patient with an elevated PSA. These liquid tests look for prostate cancer markers in the urine. One standard marker is an mRNA associated with prostate cancer that is detectable in the urine.
Prostate MRI
Over the last 10 to 15 years, prostate MRIs have become common practice and a standard of care in certain patients with elevated PSA. While MRI cannot diagnose prostate cancer, it may be able to identify lesions within the prostate that are abnormal and present changes consistent with prostate cancer.
Age-Based PSA
While a PSA of more than 4.0 is generally considered abnormal, a more accurate way of determining PSA abnormality is through the utilization of age grouping.
PSA Density
PSA density is the ratio of the PSA to the prostate's volumetric size. This ratio can also help determine whether a patient's elevated PSA would be normal for the size of his prostate gland.
Prostate Biopsy
After careful consideration of a patient's personal history, medical history, urological history, and various tests, if the healthcare provider believes that there is a significant risk for prostate cancer, then the next step would be to perform a biopsy of the prostate.
Sources
- Dr. Ramin’s email answers provided on 1/23/25.
