. Total PSA (Prostate-Specific Antigen) is a protein produced by the prostate gland.
. It can aid in identifying individuals at risk of prostate cancer, especially in those with symptoms or those undergoing routine screening (e.g., men over 50), when used alongside other tests eg., digital rectal examination (DRE), prostate biopsy, and imaging e.g., ultrasound and MRI). It may also be elevated in benign conditions like BPH or prostatitis.
. Free PSA refers to the unbound form of PSA in the bloodstream, and its levels can also be measured in conjunction with total PSA to help evaluate the likelihood of prostate cancer.
. The free PSA/total PSA ratio is particularly useful in the diagnostic workup of prostate cancer, especially in men with total PSA levels between 4 and 10 ng/mL, where the risk of cancer is uncertain. A lower ratio may suggest a higher risk of prostate cancer, whereas a higher ratio is more suggestive of benign prostatic conditions like BPH.
. In cancers, this tumor marker is used as an aid in monitoring the recurrence/progression and in assessing the response to therapy.
Note: Total and Free PSA levels can vary between different manufacturers due to differences in assay methods and reagent specificity. Results obtained from different manufacturers cannot be used interchangeably.