The Hidden Risks of Poorly Validated Lab-Developed Tests: What Patients and Providers Need to Know
With the recent court decision vacating the FDA’s rule on Lab-Developed Tests (LDTs), many laboratories will continue operating without additional federal oversight. While this may seem like a win for innovation and accessibility, it also raises serious concerns about test reliability, accuracy, and patient safety.
LDTs play a critical role in modern medicine, particularly in fields like cancer screening, genetic testing, and precision medicine. However, without standardized validation requirements, there is no guarantee that all tests provide the same accurate and meaningful results. Patients and healthcare providers must remain diligent and mindful of the risks associated with unvalidated or poorly validated tests.
Understanding the Risks of Poorly Validated LDTs
- Inaccurate Results Can Lead to Serious Consequences
Poorly validated tests can yield false positives, causing unnecessary stress, medical procedures, and even harmful treatments for conditions a patient does not actually have. Conversely, false negatives can falsely reassure patients, delaying essential care for serious illnesses like cancer or genetic disorders.
For example, some commercially available genetic LDTs have been shown to misidentify disease-associated variants, leading patients to undergo unnecessary surgeries or make uninformed decisions about their health.
- Test Performance Can Vary Between Laboratories
Unlike FDA-approved tests, LDTs are developed and validated within individual laboratories, meaning the same test may produce different results depending on where it is performed. This variability creates uncertainty and makes it harder for doctors to rely on test results when making critical treatment decisions.
For patients undergoing cancer screening or diagnostic testing for complex conditions, consistency and accuracy are paramount as even small errors can dramatically alter the course of treatment.
- Some Tests May Not Be As Reliable As Claimed
Because LDTs are not always subject to external review before being offered to patients, some tests may not perform as well as advertised. In past cases, unvalidated LDTs have been pulled from the market after real-world use revealed they were missing a significant number of true positive cases or generating unacceptable levels of false alarms.
Without independent verification, it can be difficult to determine whether a given test is truly clinically useful or just promising in theory.
How to Protect Yourself as a Patient or Provider
- Ask for Validation Data
Before relying on an LDT result, patients and healthcare providers should ask about the test’s accuracy and performance data. Key questions include:
- How was the test validated?
- What are its sensitivity and specificity?
- Has it been compared to FDA-cleared or widely accepted tests?
Laboratories should be transparent about their validation methods. If this information is unavailable or unclear, proceed with caution.
- Seek a Second Opinion for High-Stakes Decisions
If an LDT result could significantly impact your treatment plan, such as those that lead to surgery, chemotherapy, or major lifestyle changes, it is always a good idea to seek a second opinion or confirm the result with a different, well-validated test.
For example:
- If an LDT suggests a high genetic risk for cancer, consider confirming the finding with a second lab or an FDA-approved genetic test.
- If a liquid biopsy test detects cancer, additional imaging or tissue biopsy may be necessary before making treatment decisions.
- Be Skeptical of Direct-to-Consumer Tests
Many LDTs, especially genetic tests, are marketed directly to consumers, offering insights into health risks without physician involvement. While some of these tests are well-validated, others lack sufficient scientific backing and may provide misleading or incomplete information.
Before making any medical decisions based on a direct-to-consumer test, consult with a healthcare provider who can help interpret the results in the context of your overall health.
Final Thoughts: Stay Informed and Cautious
With the FDA’s LDT rule vacated, patients and providers must take extra steps to ensure diagnostic accuracy. While many laboratories follow high-quality validation practices, others may not, so it is essential to making due diligence when relying on LDTs for critical health decisions.
Being informed, asking the right questions, and seeking confirmation when needed can help ensure that medical decisions are based on reliable and accurate test results. In a landscape without universal oversight, awareness and caution are your best defenses against the risks of poorly validated diagnostic tests.
LDT Oversight: Let’s Fix the Gaps, Not Fight in Court
I recently read a very interesting post using a “frozen dinner” vs “restaurant” metaphor to differentiate between in vitro diagnostic (IVD) test kits and laboratory developed tests (LDTs). (https://lnkd.in/gYv6ZHGJ). It suggests that IVD test kits are akin to frozen dinners (i.e., mass-produced with standardized instructions and labeling), while LDTs are comparable to restaurant meals (i.e., custom-made by skilled professionals with the flexibility to adjust recipes as needed). It appears logical then that applying identical regulations to both may not be appropriate, given their inherent differences.
While the restaurant vs. frozen dinner analogy is clever, it is grossly inaccurate as it completely ignores the severity and frequency of risks associated with LDTs. Unlike food, where varying taste and presentation may please different people, clinical test results must be consistent and reliable because lives depend on them.
There is no argument that many LDTs are developed and run by highly skilled professionals. However, we cannot ignore that some labs may prioritize financial considerations over rigorous validations essential to accurate and reliable test results. Without strong regulatory oversight, test results can vary between labs, leading to inconsistent diagnoses or risk assessments for the same patient. These discrepancies can result in misdiagnosis, inappropriate treatment, or missed opportunities for critical, lifesaving care.
While the restaurant analogy seems appealing to many, it misses a critical point: consistency matters far more in diagnostics than in dining.
A patient’s test result should not depend on which lab it comes from, just as a serious medical diagnosis should not vary like a chef’s special. Many LDTs operate with high standards, but the lack of uniform oversight means that results can, and do, differ between labs, sometimes leading to misdiagnosis or inappropriate treatment.
So, let’s take the restaurant comparison further:
· Has anyone ever ordered the same dish from two different restaurants and gotten different food?
· Would you want to get two different test results from two different labs for the same medical condition?
When it comes to healthcare, consistency is not just about preference – it is about patient safety.
FDA’s final rule may not be perfect, but it is a meaningful step toward ensuring that all diagnostic tests, regardless of where it is produced, meet a baseline standard for accuracy and reliability. Rather than fighting in court, we should work together to refine and improve the framework so that patients receive the best possible care. After all, the goal is not to stifle innovation, rather it is to make sure that innovation actually benefits patients without compromising safety.