IsoPSA Testing in Kitchener-Waterloo: A Newer Approach to Assessing Prostate Cancer Risk

Prostate-specific antigen, or PSA, remains one of the most widely used blood tests for prostate cancer screening. However, PSA has an important limitation: an elevated level does not necessarily mean that prostate cancer is present. Benign prostate enlargement, inflammation, infection and other factors can also increase PSA. IsoPSA is a newer blood test designed to provide additional information about whether an elevated PSA may be associated with clinically significant prostate cancer.

Unlike a conventional PSA test, which primarily measures the amount of PSA in the blood, IsoPSA evaluates differences in the molecular structure of PSA-related proteins. Cancer can alter the structure of proteins released into the circulation. IsoPSA uses these structural differences to generate an index associated with the likelihood of clinically significant prostate cancer. This approach may help distinguish benign causes of PSA elevation from cancers that are more likely to require treatment.

In November 2025, the U.S. Food and Drug Administration approved the IsoPSA Assay to help detect Grade Group 2 or higher prostate cancer, corresponding to Gleason score 7 or greater. Its approved indication is for men 50 years of age or older with a PSA between 4 and 10 ng/mL who are already being considered for prostate biopsy. Importantly, IsoPSA does not diagnose prostate cancer by itself. An abnormal result may help determine whether further investigation, such as prostate MRI or biopsy, is warranted. A prostate biopsy remains necessary to definitively diagnose cancer.

One potential advantage of IsoPSA is potentially reducing unnecessary biopsies. Traditional PSA testing has relatively limited specificity, meaning many men with an elevated PSA undergo additional testing despite ultimately having benign disease or low-risk cancer. Clinical studies suggest that IsoPSA provides better discrimination of higher-grade prostate cancer than PSA concentration alone and may help some patients avoid unnecessary biopsy.

At True North Metabolic, we offer IsoPSA testing for eligible patients to help provide more pertinent information.