Prostate-Specific Antigen (PSA) is a protein made by both healthy and cancerous cells in the prostate gland. While its primary role is in semen, where it helps with sperm motility, small amounts are also found in the bloodstream. Because it is produced specifically by the prostate, PSA is widely used as a biomarker for detecting and monitoring prostate-related conditions, particularly prostate cancer.
A simple blood test can measure PSA levels, and this test is commonly used for prostate cancer screening, especially in men over 50 or those with increased risk due to family history. However, a high PSA level doesn’t always indicate cancer. It can also be elevated in non-cancerous conditions such as benign prostatic hyperplasia (BPH), prostatitis, or even after certain medical procedures or recent ejaculation.
In patients already diagnosed with prostate cancer, PSA is an essential tool for tracking how the disease is responding to treatment. Rising PSA levels during or after therapy may suggest that the cancer is progressing or returning. In advanced stages whether the cancer is castration-sensitive or castration-resistant PSA levels often reflect how extensive the disease is and can help guide treatment planning.
Although PSA testing is very useful, it does have some limitations. Not every case of elevated PSA means cancer, and some prostate cancers don’t produce much PSA at all. That’s why it’s important to consider PSA results along with other clinical information, such as age, rate of change in PSA over time, imaging results, and biopsy findings. Decisions about PSA testing and follow-up should be made in close consultation with a healthcare provider.