ROUTINE PROSTATE SCREENING CAN SAVE LIVES, STUDY SAYS.

Byline: Andrew Pollack The New York Times

A study announced Monday provides the first evidence that routine screening of men for prostate cancer can substantially reduce the deaths from the disease.

The research, carried out on 46,000 men in Quebec, is the first large randomized trial to shed light on a highly controversial question: Does screening apparently healthy men for prostate cancer save lives in the same way that periodic mammograms do for women, or does it merely subject men to treatments for tumors that in many cases would not harm them?

The study, by Dr. Fernand Labrie and colleagues at Laval University in Quebec, found that men who underwent screening had a death rate from prostate cancer less than one-third that of men who were not screened. Such a 69 percent reduction in deaths would translate into 27,000 fewer deaths from prostate cancer in the United States each year, Labrie said at the annual meeting of the American Society of Clinical Oncology in Los Angeles.

But some other experts said weaknesses in the study's methods leave its results open to serious question. For that reason, some said, they would not recommend that massive screening for prostate cancer be carried out in the United States until more data are available.

``This is an important and visionary study,'' Dr. Derek Raghavan, chief of medical oncology at the University of Southern California, said at a news conference at the oncology meeting. But he added, ``I'd have to say I'm not yet convinced.''

Two more big studies, one in the United States and one in Europe, are under way to address the question of whether screening saves lives, but results are not expected for years.

Prostate cancer is the second most frequent cause of cancer death in men after lung cancer. It is estimated that 184,000 cases will be diagnosed in the United States this year and that 39,000 people will die.

The controversy about screening stems from the fact that many elderly men develop prostate tumors that grow only slowly, do not spread elsewhere in the body and do not kill.

Screening all American men above age 40 or 50 for prostate cancer would cost a lot - some $12 billion a year by one estimate - and subject men to needless surgery or radiation therapy that can cause impotence and incontinence and, in rare cases, even death, Raghavan said. Moreover, the blood test used to detect prostate cancer, which looks for a protein called prostate-specific antigen, or PSA, is not that reliable an indicator of whether a patient has cancer or how advanced the disease is.

Still, some studies have shown that the PSA test, combined with a digital rectal examination, can detect most prostate cancers. But no study until now has shown that this actually saves lives.

Labrie and his colleagues took all 46,193 men between the ages of 45 and 80 who were registered to vote in the Quebec City area and randomly divided them into two groups. Two-thirds of the men were sent letters inviting them to be tested for prostate cancer and the rest were not. Of the 8,137 men who underwent annual screening starting in 1989, only five died from prostate cancer over the next eight years, a death rate of 15.0 per 100,000 man-years. But among the 38,056 men who were not screened, there were 137 deaths or 48.7 per 100,000 man-years, a rate 3.25 times higher.

Labrie said prostate cancer can be well-treated if caught before it spreads beyond the prostate gland but is almost always fatal once it has spread. In the Quebec study, in fact, four of the five deaths among the screened patients were from those who already had advanced disease by the time their first screening detected it. After the first year, virtually all the cancer cases detected through screening were localized and potentially curable.

About 90 percent of the 367 screened men who were diagnosed with the disease underwent either surgery, radiation therapy or some other treatment. Labrie, who pioneered in developing a treatment now commonly used for prostate cancer, said he thinks all men over age 50 should be tested either every year or every two years, depending upon the test results.

He said African-Americans, who have a relatively high rate of disease, and others at risk like those with a family history of prostate cancer, should be tested starting at age 40. He said the cost of mass screening would be $3,000 for each cancer case found, less than the comparable costs of mammography for breast cancer detection and Pap smears for cervical cancer detection.

But critics of Labrie's methodology pointed out that of the more than 30,000 men invited for screening, only 23 percent agreed. It is possible, for instance, that those who agreed to screening might have been those more health-conscious and therefore more likely to take good care of themselves.

``We cannot tell what the role is of all these potential biases,'' said Dr. Peter Boyle, director of the division of epidemiology and biostatistics at the European Institute of Oncology in Milan, Italy, who was the official commentator on Labrie's paper at the oncology conference.

Boyle said there was little difference in the prostate cancer death rates between the people invited for screening and those not invited. He said there were also questions about the accuracy of relying on official death registries for the cause of death in the control group.