Pathologists: In-House Experts
The in-house laboratory is a valuable resource for both clinicians and patients
sponsored by Thermo Fisher Scientific
An interview with Ruthy Shaco-Levy
Could you describe how pathology fits into precision oncology?
Pathology is developing at light speed compared with other fields of medicine – and one of the fastest-developing areas is precision medicine. I think every pathologist deals with “precision pathology” – it’s an integral part of the pathology report. For example, if we find a case of breast cancer, we report on tumor grade, tumor size, and receptor status. Separating molecular pathology is artificial; why would you select one part of the examination process and complete it in a separate place?
Why do you test in-house at your institution?
Israel has a “national health basket” of drugs and diagnostic tests. Hospital laboratories perform all tests included in the basket. Initially, we did a lot of immunohistochemistry and PCR; now, we do much more of our testing with next-generation sequencing (NGS) because it’s more efficient and more accurate.
It’s important for me as a pathologist to correlate my findings with each test result. For example, if I have a breast cancer case that looks like a low-grade lobular or ductal carcinoma and HER2 comes back strongly positive, I have to ask myself some important questions: Do the results make sense? Is my diagnosis correct? Ultimately, I might choose to repeat the tests or to confirm my diagnosis – and that’s something that can only really be done if you test in-house.
Also, we must not forget to develop our pathologists. Molecular pathology is an increasingly vital part of our profession and, if pathologists and laboratory medicine professionals aren’t given the opportunity to practice, we won’t be able to use those tools when we need them. We play a key role in patient care, and we owe it to them to keep our abilities honed.
Have you had experience with centralized testing?
A few years ago, my hospital chain tried to centralize our laboratory testing. Unfortunately, the lab was not equipped to handle our testing needs or connected to a pathology department and, to make a long story short, it failed. Over the few years of our centralization, a wide gap developed between our capabilities and those of hospitals that had not been centralized. Fortunately, since our testing moved back in-house, we’ve closed that gap.
Last year, there was an initiative to move all non-small cell lung cancer (NSCLC) NGS testing in Israel to a large commercial laboratory from overseas. The Israeli Association of Pathologists and other experts, including oncologists, strongly opposed this for many reasons: long turnaround times, loss of the ability to coordinate the patient care in cross-disciplinary tumor boards on-site, and more. As a result of this opposition, from July 2020 onward, local pathology departments will perform all DNA/RNA NGS analysis for NSCLC patient samples – the best possible outcome for patients, pathologists, and the healthcare system as a whole.
So what are the key benefits of in-house testing?
First, reducing turnaround time to results; some cancer patients have a very rapid clinical course and need test results right away – especially for companion diagnostics. If we send material abroad, it can take weeks to get the results. Patients can’t wait that long to start treatment, so they may receive ineffective or even harmful chemotherapy. Turnaround time is critical in pathology in general, and especially in molecular pathology for cancer patients.
Second, preserving precious sample. Many hospitals use smaller panels for their precision testing. In lung cancer, for instance, you can assay a few dozen genes or you can assay hundreds. The more genes you test, the more biopsy tissue you need – and the less remains for future tests. When we test in-house, we carefully select our tests based on the available material. By only asking the most important questions, we make sure there’s enough material to get answers.
And third, keeping tissue in-house. As noted, biopsy material is precious; sending it out risks loss or damage. Even if the sample reaches its destination safely, we may not receive any material back because other labs may test less conservatively, forcing patients to undergo another biopsy if they need further testing. It’s far safer to avoid sending tissue out at all.
It’s the pathologist – the expert – who selects the appropriate assay based not only on how much tissue is available, but also its quality. In-house, that decision can be made on a case-by-case basis, but central labs often apply the same large panels to all material – and those panels are “all-or-nothing,” so if there isn’t enough material, you can’t prioritize the most important genes. That means patients with insufficient high-quality tissue must undergo a repeat biopsy or risk having no answers at all – an unacceptable outcome that makes in-house testing vital for true precision oncology.