Using the Prostate Health Index test to help diagnose prostate cancer significantly reduces unnecessary and expensive biopsies, a study reports.
Beckman Coulter came up with the tool for patients whose digital rectal exam yields nothing suspicious but who have high levels of PSA. Elevated levels of that protein are the main biomarker of the disease.
U.S. regulators approved the index as a diagnostic tool in 2012.
Researchers published their study in the journal Prostate Cancer and Prostatic Diseases. The article was titled “Clinical Utility of the Prostate Health Index (phi) for Biopsy Decision Management in a Large Group Urology Practice Setting.”
The Prostate Health Index is based on the results of three blood tests — total PSA, free PSA, and a PSA precursor known as p2PSA. The combined test scores give doctors an idea of whether a man is likely to have prostate cancer.
While the scores do a much better job of detecting prostate cancer than total PSA or free PSA scores alone, little has been known about whether the index was reducing prostate cancer biopsies.
In the first part of the study, Dr. Jay White of Carolina Urology Partners and colleagues asked urologists to take a two-part questionnaire. It dealt with whether the doctors were using Prostate Health Index scores in their biopsy decisions or just to help monitor patients.
The second part of the study looked at 683 biopsy decisions that doctors made before the index came along, versus 506 biopsy decisions after the index appeared.
Signs that a doctor ought to perform a biopsy are not always obvious. Decisions become particularly difficult when a digital rectal exam shows no reason to worry but a blood test shows high PSA levels.
More than two-thirds of such biopsies indicate no cancer is present when PSA levels are in a certain range. This means most biopsies are unnecessary and pose a risk of bleeding and infection.
The study’s key finding was that doctors performed biopsies in only 36 of the men whose index scores they had checked. The rate was 60 percent before doctors began using index scores.
Another finding was that doctors detect fewer cases of low-grade prostate cancer since the index appeared.
“Physicians were less inclined to do a biopsy on patients receiving a low phi [Prostate Health Index] score, and more inclined to recommend biopsy for patients receiving an intermediate to high-risk phi score,” White said in a press release. “It also improved a physician’s ability to communicate their recommendation to the patient, and helped alleviate patient anxiety in cases where the phi score was low. The appropriate use of the Prostate Health Index can significantly modify physician behavior patterns and improve their ability to diagnose and manage their patients.”
The study was the first to look at the index’s value in a multi-center private-practice setting. It involved urologists at four specialized practices across the United States.