FDA Endorses Blood Test to Help in Detecting Prostate Cancer

The Food and Drug Administration put its stamp of approval Monday on a simple blood test that many doctors have used in recent years to help detect prostate cancer in men 50 and older.

Although the FDA had approved the blood test in 1986 to aid patients being treated for prostate cancer, Monday’s endorsement is the first to allow its use for diagnostic purposes when done in conjunction with a rectal exam.

FDA officials cautioned that the test, a prostate specific-antigen procedure, should not be relied upon exclusively to determine whether a man has prostate cancer. Rather, it should be used to complement a rectal exam by a physician, officials said.

Federal approval of the test developed by Hybritech Corp. of San Diego, a unit of Eli Lilly & Co., was based on a review of clinical studies on safety and effectiveness submitted by Hybritech and on the recommendation of FDA’s immunology devices panel.

In a study of more than 6,300 men, the panel said that the blood test, when combined with a rectal exam, is much more effective in detecting prostate cancer than either a rectal exam or the blood test alone. But a final diagnosis always requires a biopsy, the panel said.

With a small vial of blood drawn from a man’s forearm, the test measures the level of a protein called prostate-specific antigen that circulates in the bloodstream. When these antigens are found at elevated levels, they are a sign of prostate cancer, benign prostatic hyperplasia or other prostatic problems, physicians said.

According to the National Cancer Institute, 27% of all U.S. cancer cases involve the prostate, a walnut-sized gland at the base of the bladder that produces the fluid portion of semen.

After age 50, most men at some point experience enlargement of the prostate, which can cause difficult or painful urination. In most cases the enlargement is benign.

However, about 38,000 men die from prostate cancer annually. The institute estimated that 200,000 new cases will be diagnosed this year, as numbers have grown along with better diagnostic techniques.

Prostate cancer, in fact, is the most common malignancy among American men and the second-leading cancer killer, after lung cancer, according to the American Cancer Society.

Once nascent tumors are detected, the earlier the treatment, the better the chance of recovery, the cancer society said.

FDA Commissioner David A. Kessler said that the blood test, “when used with other procedures, can help detect those men at risk for prostate cancer early on when more treatment options are available.”

“But for the test to help, men must be aware of the importance of early checkups and get them on a regular basis,” Kessler said.

The cancer society has enlisted famous Americans in recent years to talk about being treated after they were diagnosed as having the disease.

The spokesmen have included Senate Minority Leader Bob Dole (R-Kan.), former Sen. Alan Cranston (D-Calif.), Supreme Court Justice John Paul Stevens and former professional athletes, such as baseball Hall of Famer Stan Musial and tennis star Bobby Riggs.

Doctors are divided on whether surgery to remove the prostate should be undertaken whenever cancer is detected.

In the case of younger men or slow-moving cancers, some physicians recommend a long period of watchful waiting to avoid the risks inherent in surgery.