According to a new study published in the Journal of Urology researchers at NewYork-Presbyterian Hospital and Weill Cornell Medical Center have successfully developed and tested a new prostate cancer-screening test. The test is a combination of a novel drug therapy and PSA level changes over time in order to identify men with a high PSA who have a higher risk of developing aggressive prostate cancer even though they had negative biopsies.

The study demonstrates that PSA can be a much more effective marker for prostate cancer when used in addition to drug therapy compared to the currently used stand-alone test.

Leading researcher Dr. Steven A. Kaplan, the E. Darracott Vaughan Jr., Professor of Urology at Weill Cornell Medical College and director of the Iris Cantor Men’s Health Center at NewYork-Presbyterian/Weill Cornell, said: ”At a time when the value of PSA is being increasingly debated, we have shown that when used in a specific way, it can be of great value in identifying men with previously undetected prostate cancer.”

Dr. Kaplan, who is also chief of the Institute for Bladder and Prostate Health at NewYork-Presbyterian/Weill Cornell, continues:

”We have shown that using PSA with these drugs can help us differentiate prostate cancer from benign prostate disease in patients who are difficult to diagnose. It also demonstrates a better way to use both the PSA test and these powerful drugs.”

Kaplan developed the combination screening method in order to gain a better insight into the risk of cancer in men with consistently abnormal PSA readings despite one or more negative biopsies. Kaplan refers to this patient group as a “diagnostic dilemma” for physicians, “despite the fact that biopsies are becoming more and more effective at detecting cancer in the prostate, a significant number of patients with prostate cancer continue to have negative biopsies.” He continues saying that the current PSA (prostate specific antigen) test alone is not a good indicator of prostate cancer, remarking: “It measures multiple factors associated with prostate disease, including enlargement of the prostate and inflammation.”

The researchers wanted to learn what would happen to PSA levels after the use of two 5-alpha-reductase inhibitor drugs, i.e. finasteride and dutasteride, which are designed to decrease the size of an enlarged prostate. Hypothetically, these drugs could potentially improve PSA’s use in diagnosing prostate cancer. They believe it could indicate the presence of cancer if PSA levels remain persistently high despite prostate shrinkage, or PSA elevates after having reached its lowest level. A biopsy could also be more effective when the gland is smaller they add.

The team enrolled a total of 276 men at NewYork-Presbyterian/Weill Cornell whose PSA was greater than 4, who had a normal digital rectal examination and two or more negative biopsies in their two-phase study.

The first phase entailed a daily administration of 5 mg of finasteride or 0.5 mg of dutasteride to 97 patients. The participants’ PSA was measured at 6 and 12 months, and a transrectal ultrasonography and a biopsy was performed at 1 year. According to the results, after a year of drug therapy the PSA level was reduced in all the men by an average of 48%. However, the magnitude of reduction was considerably greater in those with benign prostate disease and substantially less (28%) in patients whose prostate biopsy identified cancer.

The second phase entailed giving the same drug therapy to 179 patients, but these patients only had a biopsy if their PSA displayed a change of 0.4 ng/dl. As a result, 42 men or 27% underwent a biopsy, of which 26 men (54%) were diagnosed with cancer. In this patient population, 77% of patients were diagnosed with high-grade tumors.

The team managed to successfully detect cancer in those men who took part in the second phase study, which entailed the combined drug therapy and evaluation of PSA trends, and only sending those men who had minimal PSA changes for a biopsy, meaning that only those who really needed a biopsy had one compared with all the men in the first phase of the study.

Dr. Kaplan concludes: “Our study shows these drugs may be most helpful in helping us diagnose undetectable prostate cancer.”

Written by Petra Rattue