“It’s early, but the data are very promising so far in head and neck cancer,” Dr. Zevallos said.
Explore This Issue
December 2022Rhinology
Precision diagnostic techniques aren’t yet ready for prime time in rhinology. “Within the field, we now have proof of concept that if you can determine a patient’s inflammation category and then block that pathway with a very highly specific antibody, you can actually modify the disease,” Dr. Bleier said. But while there are some companies that will run a microbiome analysis or microtyping on nasal mucous samples, “it hasn’t gotten to the point where you can do this for an array of cytokines or other inflammatory biomarker,” he added.
Researchers are still working to identify clinically useful and meaningful biomarkers, with that work often paralleling the development of different therapeutic modalities, particularly biologic agents. Ultimately, Dr. Bleier believes that “the presence and elaboration of therapeutic options will drive the elaboration of more precise biomarker analysis and testing.” At present, with a limited number of FDA-approved biologic agents to treat chronic rhinosinusitis, it’s simply easier to prescribe the biologic that’s most likely to work given a particular clinical context and switch if needed, rather than trying to use precision diagnostics to direct treatment.
Ongoing research will likely shift rhinologic diagnosis from phenotypic diagnoses to endotypic diagnoses, and it’s likely that analysis of nasal mucus will play a key role. “Multiple studies have come out that have looked at cytokine levels in mucus alone and been able to differentiate patients into various groups,” Dr. Bleier said. One study that measured 17 mucus cytokines and inflammatory mediators in 147 patients with chronic rhinosinusitis, for instance, found that patients 60 years and older had elevated mucus levels of IL-1β, IL-6, IL-8, and TNF-α when compared to their younger counterparts (J Allergy Clin Immunol. 2019;143:990–1002.e6).
Otology
“The inner ear remains the last organ system you can’t biopsy,” said Hinrich Staecker, MD, PhD, the David and Mary Zamierowsky Endowed Professor in the department of otolaryngology at the University of Kansas School of Medicine in Kansas City. Liquid biopsy presents a unique opportunity to better understand the pathophysiology of the inner ear.
Dr. Staecker and others have invested significant efforts in elucidating the composition of perilymph fluid, utilizing samples obtained during cochlear implantation and surgeries to treat vestibular schwannoma. One study that utilized mass spectrometry to analyze the proteome of human perilymph in 36 patients with sensorineural hearing loss undergoing cochlear implantation found the proteins short-chain dehydrogenase/ reductase family 9C member 7 and esterase D in nearly all samples from patients with Ménière’s disease but none of the samples from patients with enlarged vestibular aqueduct or otosclerosis (ACS Omega. 2021;6:21241–21254). The potential of these two proteins to serve as a biomarker for Ménière’s or other inner ear diseases is an active area of research.