WASHINGTON — Proposed federal rules to require new government approval of certain tests developed in medical schools and private business laboratories have drawn cries of protest from the Mayo Clinic.

The proposed rules would for the first time make labs designing the tests prove their effectiveness to the U.S. Food and Drug Administration (FDA). Test developers also would have to formally report to the government problems that occur with the tests after they become available.

Mayo says it already goes through a certification process with other federal agencies and monitors its so-called adverse events. The clinic recently sent the chairman of its laboratory medicine and pathology department to Washington to testify against the rules as the government considers tweaking them.

"These rules have the potential to get in the way of effective patient care and really disrupt the whole patient-physician-laboratory relationship," Dr. Curtis Hanson told the Star Tribune after his testimony to the FDA.

At stake for Mayo is a major portion of its lucrative laboratory testing service, which is part of a national $65 billion-a-year industry that is among the fastest growing sectors of U.S. medical technology.

Mayo offers 1,600 lab-developed tests among an array of 3,500 tests. A Mayo business subsidiary performs these tests for the patients of 4,000 clients nationwide and around the world. The subsidiary has performed 2.5 million tests for Mayo's on-site patients in the past six years. But it has performed 18 million tests for outside clients in that period.

If they stand, the new FDA rules could cut deeply into the tests Mayo and others will be able to perform for outside clients, Hanson said.

The FDA calls such charges "exaggerating." The agency says that several lab tests for serious health conditions have not worked correctly and have hurt patients. Those problems led the FDA to seek proof of clinical effectiveness of certain tests for certain conditions before those tests can be used.

Companies competing for market share in the lucrative lab testing sector are not always forthcoming about the shortcomings of their tests, said Alberto Gutierrez, FDA director of in vitro diagnostics and radiological health. "No one looks at their clinical validity" of lab developed tests before they're used, he said.

Gutierrez pointed to OvaSure, a test that was supposed to allow early detection of ovarian cancer. The test rendered extensive numbers of false positives that in some cases led to surgeries to remove healthy ovaries, he said.

He also mentioned a noninvasive prenatal test for Down syndrome that gave false positives that in at least one case appeared to lead to the termination of a pregnancy.

The American Clinical Laboratory Association (ACLA) estimates there are "tens of thousands" of lab-developed tests currently offered by U.S. labs. The ones facing regulation are mostly genetic and molecular tests created in labs.

"These tests are being modified all the time for things like Ebola and flu virus," said ACLA President Alan Mertz. "We're talking about thousands of innovations in cancer and infectious disease. To stifle that derails advances in medicine."

Mertz said the ACLA is considering suing the FDA if it does not withdraw its new premarket approval regimen and post-most market reporting requirements. "If you go to premarket approval [of genetic and molecular] tests," he said, "it can take years and cost tens of millions of dollars."

Hanson said many people have the mistaken impression that laboratory developed tests "are like the wild, wild West" because the testing business model has changed. Where tests were once developed by institutions mostly for their patients, testing services are now sold to outside clients. But the tests, he said, still fall under the oversight of the Clinical Laboratory Improvement Amendments administered by the U.S. Department of Health and Human Services.

The FDA's Gutierrez countered that the new rules will monitor tests in ways that the government currently does not. So they offer more patient protection. Gutierrez said no one knows precisely how many lab-developed tests there are or what they are used for. The FDA wants to build an accurate inventory, then move to premarket approval of high- risk tests. He said the new rules would initially only apply to roughly 5 percent of laboratory developed tests. Other protocols would be phased in over many years, he said.

At the University of Minnesota, Dr. Anthony Killeen, vice chairman of the laboratory medicine and pathology department, has mixed feelings about the new FDA rules. The school has not taken a position. What it hopes for, he said, is a single standard.

"A lot of genetic testing is stuff we develop ourselves," Killeen said. "The big kahuna here is genetics. We're at the cutting edge of science and medical practice."

But the lab-testing industry has grown enormously and quickly, he added, and "a number of entities market tests with questionable clinical utility."

"The public has an interest in that," Killeen said. "So there's some merit to what the FDA is doing."

Fairview Health Services, part the U's medical system, performs lab tests for roughly 200 outside clients. Killeen said lab tests developed in-house have not been subject to premarket approval, but the U already monitors adverse events across its entire health system, including lab tests.

Killeen does not expect the new rules to have a big impact on his operations. He said if any of his major outside clients needed tests that FDA wanted to approve, he would follow the approval process.

But Killeen warned that adding a layer of regulatory approval "may slow down availability to tests." And he also warned of thinking that more regulation is a silver bullet. FDA clearance "doesn't mean something can't go wrong. The most common problem with lab tests is mislabeling the sample," he said.

Jim Spencer • 202-383-6123