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[ dxtrending ] Multiplexing at the Molecular Level MOLECULAR PANEL TESTS ARE MAKING INROADS AGAINST COMPLEX GENETIC DISEASES Peter D. Beitsch, MD, Dallas Breast Center. Robert Jenison, Great Basin Scientific. By Gary Tufel O ver the past several years, molecular diagnostic testing has become increasingly common in clini- cal laboratories, in part because of a correspond- ing increase in the number of players involved in developing multiplexed molecular tests. Whether the roots of this trend lie in a need for more markers per panel, faster turnaround time, greater use of automation, or something else, one thing remains certain: laboratories desire more multiplexed solutions. Multiplexing creates tests that are beneficial to patients as well as to healthcare providers’ bottom-lines. Patients can be tested for multiple diseases during a single visit, enabling healthcare providers to know sooner what type of counsel- ing and treatment needs to be considered. Meanwhile, pay- ers and providers can capitalize on existing infrastructure to expand testing capabilities, offering more comprehensive services to patients while maximizing the use of testing resources. Russell A. Peloquin, vice president of global commercial operations at SQI Diagnostics Inc, Toronto, Ont, Canada, recommends that in vitro diagnostic manufacturers ask themselves three things when developing new tests for their platforms: • Does the assay provide more relevant data for the clini- cian? • Do the assay and its platform reduce the potential for human error? • Does the assay improve the workflow of the performing laboratory? If the answer to all of these questions isn’t a firm “yes,” he says, diagnostics companies should think twice about the practicality of the assay. “These considerations inevitably lead to the idea of multiplexing—measuring multiple bio- markers from a single biological sample—which can make it possible for labs to achieve all of these goals at once.” 18 January 2016 | clpmag.com Nowhere has this idea taken hold more than in the area of genetics, where researchers are increasingly finding that genetic diseases are caused by the interaction of many chromosomal abnormalities. The vast number of algorithms required to calculate such genetic variations has been enough to give birth to an entire cottage industry known as genetic counseling, observes Peloquin. “But how is that vast cacophony of data generated in the first place? Multiplexed diagnostic testing,” he adds. Johnathan Lancaster, MD, PhD, Myriad Genetic Laboratories. CANCER GENE PANELS OFFER WIDE APPLICATIONS The increasing availability of relevant molecular panel tests is already changing the standard of care for some dis- eases. According to Peter D. Beitsch, MD, FACS, director of the Dallas Breast Center, Dallas, and past president of the American Society of Breast Surgeons, molecular panel testing for metastatic cancer has previously been performed mostly for patients who have failed multiple established treatment regimens. But this practice is changing. “The most common cancer types are breast, colon, lung, melanoma, and renal cell,” says Beitsch. “For lung cancer and melanoma, the standard of care is now to check for certain molecular markers at the beginning of treatment for metastatic disease—not after failing a round or two of stan- dard treatment—since certain cancers are exquisitely sensi- tive to targeted therapy. Two examples of this are crizotinib in ALK-mutated lung cancers (about 2% of all lung cancers), and vemurafenib and cobimetinib (or other BRAF and MEK inhibitors) for BRAF V600 mutation in melanoma patients (about 50% of all melanomas),” Beitsch says. “As we are learning more about all cancers, it is appar- ent that there are certain pathways that are common to cancers that originate in many different tissue types,” Beitsch explains. “For example, BRAF mutation occurs in approximately 10% of colon cancers, 5% of thyroid cancers, 2% of breast cancers, and 1% of lung cancers. Soon, we will Russell A. Peloquin, SQI Diagnostics. Wade Stevenson, BioFire Diagnostics. Doug White, BD Life Sciences.