Value of PSA and Free PSA Tests Validated in New Prostate Cancer Guidelines

New guidelines from the independent National Comprehensive Cancer Network (NCCN) strongly support the prostate specific antigen (PSA) and percent-free PSA blood tests to aid in the detection and treatment of prostate cancer.

Beckman Coulter's Hybritech(r) PSA and Hybritech free PSA were the first such tests approved by the Food and Drug Administration.

"The development of PSA testing is arguably the most important advance that has been made in detecting prostate cancer at an early stage," the guidelines state. NCCN is an alliance of 19 of the world's leading cancer centers.

"PSA is the best cancer tumor marker in all of medicine. It is even more accurate for prostate cancer than mammograms are for detecting breast cancer," said William J. Catalona, M.D., one of the world's foremost prostate cancer specialists and director of the Clinical Prostate Cancer Screening Program at Northwestern Memorial Hospital in Chicago.

Dr. Catalona is a member of the NCCN Prostate Cancer Early Detection Panel, which developed the guidelines. Dr. Catalona's numerous published articles on PSA testing have used Beckman Coulter's PSA and free PSA tests.

Both the NCCN and the American Cancer Society recommend annual PSA blood tests for most middle-aged and older men. ACS recommends most men get annual PSA test beginning at age 50.

"Prostate cancer is the most commonly diagnosed and second-leading cause of cancer death in American men," said Bernard Cook, Ph.D., lead scientific advisor. "The simple, inexpensive and widely available PSA blood test continues to play an important role in assisting physicians, laboratorians and patients in assessing prostate health and monitoring treatment of the disease."

The NCCN guidelines state: "Prostate cancer cases detected through PSA screening are more often confined to the prostate than those detected solely by DRE" - or digital rectum exam - meaning PSA-detected cancers are less likely to have spread to other parts of the body.

The NCCN guidelines also make recommendations on the appropriate age to begin PSA testing, the value of percent-free PSA testing, the potential advantages of monitoring the rise in a man's PSA level from one year to the next, and other topics.

PSA as a screening test does have its critics, who contend PSA testing may not be as accurate and therefore not as valuable as previously thought. They fear that the test leads to too many unnecessary biopsies and that, even when the biopsy is positive, the cancer is often not life-threatening.

In response, Dr. Catalona notes that clinical studies show that most prostate cancers detected through PSA testing have the features of tumors that are likely to clinically affect patients.

Dr. Catalona also points out that tests such as the Hybritech free PSA test can reduce unnecessary prostate biopsies in individuals with moderately elevated PSA levels. The free PSA test improves the accuracy of total PSA tests when used as a follow-up to an initial PSA test like Beckman Coulter's Hybritech PSA.

The Hybritech PSA test is used to measure serum PSA in conjunction with DRE as an aid in the detection of prostate cancer in men 50 and older. Prostate biopsy is required for cancer diagnosis. The Hybritech PSA assay also is used for serial measurement of PSA, to aid in the prognosis and management of patients with prostate cancer.

"There are appreciable differences between prostate cancer tests," said Dr. Catalona. He emphasized the importance of men getting their PSA levels checked annually using the same test at the same facility: "If you use different tests from one year to the next, you can get different PSA results, which could lead to inaccurate diagnoses and treatment."

Through the collective expertise of its member institutions, the non-profit NCCN develops, updates and disseminates a complete library of clinical practice guidelines. No industry support is accepted for any costs associated with the development of the guidelines.