Among middle-aged and older men, those who have had PSA tests are less likely to be found to have Prostate cancer that has spread to other sites in the body, Canadian researchers report.

Dr. Jacek A. Kopec told Reuters Health, “There was a 35 percent reduction in risk among those who were screened.”

Further, he added, “We observed a reduction in risk for both men under 60 years of age and those 60 years or greater, although the effect appears to be stronger in younger men.”

Kopec, of the University of British Columbia, Vancouver, and colleagues conducted a population-based study involving 236 cases of metastatic Prostate cancer - i.e., cancer that had spread beyond the prostate.

They were compared with 462 similar men drawn from the metropolitan Toronto area who did not have metastatic Prostate cancer, although they could have localized Prostate cancer.

Based on the medical records, the rate of PSA screening was significantly lower in men with advanced prostate cancer than in the comparison group, the team reports in the August issue of the Journal of Urology.

In those between 45 and 59 years of age, screening reduced the odds of having metastatic cancer by 48 percent, and in men between 60 and 84 years old, by 33 percent.

Kopec noted that the value of PSA screening is debated, because it hasn’t been shown to reduce mortality rates from Prostate cancer. “We believe our study contributes to this debate in an important way,” he said, “because it offers new evidence that screening with PSA can reduce the risk of death from Prostate cancer - the evidence is indirect as the outcome we looked at was metastatic cancer rather than death.”

In an accompanying editorial, Dr. Gerald L. Andriole of Washington University School of Medicine, St. Louis, Missouri, broadly agrees, pointing out that “few urologists would have difficulty in accepting the notion that PSA screening results in detection of Prostate cancer before it becomes metastatic.”

SOURCE: Journal of Urology, August 2005.