A Reason to Dread Prostate Tests a Bit Less
Doctors have long had difficulty convincing men of the need for annual prostate cancer screenings. After all, one portion of the exams is extremely uncomfortable, and many experts disagree on their effectiveness at reducing deaths.
But a new study could make the screenings, which involve a blood test and a rectal exam, somewhat easier to take. In trying to determine whether the exams save lives, researchers have found that, for many men, the screenings may be necessary only every five years.
The results will probably be incorporated into future cancer screening guidelines, said Dr. Harmon Eyre, research director for the American Cancer Society.
“I won’t say that we will immediately change our guidelines, but we will take a careful look at it,” he said.
Current guidelines recommend that men over the age of 50 receive a yearly rectal exam and PSA test, which measures the level of a protein, called the prostate-specific antigen, that is released into the blood by a tumor. A PSA reading of 1 or less is generally taken to mean that a man does not have prostate cancer. A reading between 4 and 10 indicates a 40% chance that he has a tumor; a reading over 20 indicates virtually a 100% risk.
The new findings suggest that men who score at the lowest levels on the PSA test could go as long as five years between tests. Men with intermediate scores could have the test every other year, said Dr. E. Edward Crawford of the University of Colorado, who headed the new analysis.
“We have found that the vast majority of men whose initial PSA levels are very low do not need to worry that [the levels] would skyrocket within one year,” Crawford said.
If the new recommendations are adopted, the annual number of PSA tests could be cut in half, saving the health care system between $500 million and $1 billion annually, Crawford said. He presented the results last week at an Orlando meeting of the American Society of Clinical Oncology.
Prostate cancer is expected to strike 189,000 men in 2002, killing 30,200, according to the organization.
Before the PSA test was widely adopted, about three-quarters of all prostate tumors were detected in the late stages of the disease when they were not readily treatable, according to Dr. Richard N. Atkins, president of the National Prostate Cancer Coalition. Now, he said, three-quarters of the tumors are caught early, giving men a fighting chance.
Atkins noted that there has been a 27% decline in prostate cancer deaths over the last five years, which he attributes primarily to PSA testing.
But PSA tests are controversial--in part because prostate tumor screening is itself controversial. Oncologists recognize two different types of prostate tumors: those that are fast-growing and generally lethal, and those that are very slow-growing and that usually do not kill their hosts.
Right now, there is no way to distinguish between the two forms of the disease.
The slow-growing form is probably more common, however, and physicians say that large numbers of men die with prostate cancer, but not from it. That is, they have a tumor, but die of other causes.
Critics of screening charge that treatment of these essentially benign tumors leaves many men suffering from impotence or incontinence, whereas not treating them would not adversely affect their health.
The new study is, in fact, part of a larger analysis to determine whether prostate cancer screening saves lives. But that larger analysis has not been completed.
Crawford and his colleagues examined medical records for 27,863 men between the ages of 55 and 74; 55% of the men had an initial PSA reading less than 2. They found that 98.7% of men whose initial PSA value was 1 or less had a reading that was still under 4 five years later. Similarly, 98.8% of those whose initial reading was between 1 and 2 still had a reading under 4 two years later.
They recommended that:
* Men whose initial PSA value was 1 or less do not need another test for 5 years.
* Those whose PSA value was between 1 and 2 should receive another test in two years.
* Those whose PSA value was between 2 and 4 should continue to have annual tests.
“When we first thought about screening, we thought it should be done every year,” Crawford said. “We had no data to suggest otherwise. Now we have data that lets us step back.”
