Federal health regulators indicate that laboratory developed tests (LDTs), which are designed to examine tissue samples, may be doing more harm than good, due to potentially inaccurate results and a lack of regulatory oversight.
The FDA is calling for increased regulatory power over the laboratory tests, which are starting to be marketed nationwide, according to a report on LDTs (PDF) released earlier this month by the agency.
According to the findings, some tests currently on the market may lead to a misdiagnosis, telling patients they have a disease or condition they do not have, or result in a failure to diagnose serious health problems.
The FDA’s report looked at 20 such LDTs, which the FDA says are growing in complexity and in the scope of the ailments they are designed to diagnose.
Previously, the agency has taken a hands-off approach to the studies, because they were simple, confined to local labs, and often used to diagnose rare conditions, Dr. Peter Lurie, Associate Commissioner for Public Health Strategy and Analysis, said in an FDA Voice blog on November 16.
“LDTs have increased in complexity and availability and are now frequently used to diagnose common, serious medical conditions, including cancer and heart disease, with potentially greater impact on patients. And yet, LDTs are still under a general policy of enforcement discretion,” Lurie wrote. “That means they have rarely undergone FDA review to determine whether they are accurate, reliable, and provide clinically meaningful results. It also means that FDA’s own adverse event reporting databases rarely capture problems associated with a faulty LDT.”
In addition to a lack of adverse event reporting, the FDA report found that there is no premarket review of LDTs, manufacturers often make unsupported claims about their effectiveness, there is inadequate product labeling, a lack of transparency, and that other laboratories that have to go through official vetting processes are at an unfair disadvantage to LDTs.
The agency’s report also noted that LDTs could be a threat to the scientific integrity of clinical trials when researchers rely on their results.
According to the findings of the report, one test used to detect ovarian cancer had no evidence that it was effective, and may have resulted in false-positives that led to women unnecessarily having their ovaries removed.
Some of the tests targeted genetic variants that were at one time suspected of being linked to an increased risk of heart disease, but that link has never been proven. However, as a result, more than 150,000 people took the tests and then based their use of cholesterol-lowering drugs on the results.
Another unproven test may have wrongly diagnosed children as having autism, the findings indicate.
“We were able to derive an estimate of the public health cost for five of the 20 cited tests,” Lurie wrote. “For the CARE Clinical Autism Biomarkers Test alone, FDA economists estimated a total public health cost of $66.1 million.”
The FDA submitted the report to Congress, arguing that increasing the agency’s oversite over LDTs was crucial in protecting public health.