What is Prostate-Specific Antigen and Why Is It Important For Patients with Prostate Cancer?

Prostate-specific antigen (PSA) levels can be among the key factors for patients with prostate cancer to be mindful of following treatment, one expert explained to CURE®.

PSA, a protein which is associated with the presence of prostate cancer in the body, is one of factors recently identified by researchers as potentially indicative of which patients with prostate cancer are at high risk for a shorter time until prostate-specific antigen recurrence and failure.

A secondary analysis of a phase 3 clinical trial, results of which were published in JAMA Network Open, found that among patients with nonmetastatic, unfavorable-risk prostate cancer, those who were younger than 70 years old and had a PSA level of 10 ng/mL, as well as a Gleason score (which grades prostate cancer based on a pathologist’s review of a biopsy or surgical specimen on a scale of 2 to 10) of 8 or higher had a 43.8% risk of PSA failure at three years.

Study co-author Dr. Mutlay Sayan, an instructor at Harvard Medical School and radiation oncologist at Brigham and Women’s Hospital and Dana-Farber Cancer Institute in Boston, spoke with CURE® about the importance of monitoring PSA levels, which he advised should be tested at least every six months, following completion of treatment.

“What we know is, the shorter the time to recurrence following a treatment in this group of patients, they (more that patients) tend to have not good clinical outcomes,” Sayan said.

Visits with a patient’s provider will include testing of PSA levels within a few months following treatment, according to the website of the American Cancer Society. While the ACS notes that the frequency of follow-up visits and testing may depend on the stage of a patient’s cancer and its chances of recurrence, most doctors will recommend PSA levels be tested approximately every six months for the first five years after treatment, then at least annually after that.

Testing of PSA levels, Sayan noted, are relatively simple from the patient’s perspective.

“It's just a quick blood draw in an office,” he said. “It's just one needle on your arm and collecting blood. And that's as simple as that is. And it's the best way to monitor (PSA levels) following the definitive treatment.

Transcript:

The best way to monitor after a definite of treatment is to check the PSA level. When the PSA level is reaching a certain point that the patient will be determined to have a biochemical failure, the failure due to PSA rising. That is an indication, perhaps, that the clinical outcome will be worse, and more so in the patient that has a shorter interval time following their definitive treatment. That information itself is important, (because) that can tell us which group of patients that we can do at an early intervention (for). Or (it tells us) before they get their treatment, that we can do a treatment escalation. Those are questions that need to be answered with a (well) designed clinical trial.

This transcript has been edited for length and clarity.

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