A report by Wang et al in The Journal of Molecular Diagnostics described the use of acoustofluidics, a noninvasive method that analyzes saliva for the presence of human papillomavirus type 16 (HPV-16), the pathogenic strain of the disease associated with oropharyngeal cancers. This novel technique detected oropharyngeal cancer in whole saliva in 40% of patients tested and 80% of patients with confirmed oropharyngeal cancer.
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“Oropharyngeal cancer has an approximate incidence of 115,000 cases per year worldwide and is one of the fastest-rising cancers in Western countries due to increasing HPV-related incidence, especially in younger patients. It is paramount that surveillance methods are developed to improve early detection and outcomes,” explained co-lead investigator Tony Jun Huang, PhD, of the Department of Mechanical Engineering and Materials Science, Duke University.
“Considering these factors, the successful detection of HPV from salivary exosomes isolated by our acoustofluidic platform offers distinct advantages, including early detection, risk assessment, and screening,” added Dr. Huang. This technique may also help physicians predict which patients will respond well to radiation therapy or achieve longer progression-free survival.
Exosomes are microvesicles originating within cells that are secreted into body fluids. They are believed to play a role in intercellular communication and their numbers are elevated in association with several types of cancers. Acoustofluidics is an advanced technology that fuses acoustics and microfluidics. Fluid samples are analyzed using a tiny acoustofluidic chip developed to isolate salivary exosomes by removing unwanted particles based on size, leaving exosome-rich concentrated samples that make it easier to detect tumor-specific biomarkers.
In this study, investigators analyzed saliva samples from 10 patients diagnosed with HPV-associated oropharyngeal cancer using traditional methods. They found that the technique identified the tumor biomarker HPV-16 DNA in 80% of the cases when coupled with droplet digit polymerase chain reaction. Since this method is independent of sample variability that arises due to changes in saliva viscosity and collection methods used, it may prove ideal for use in clinical settings.
Dr. Huang highlighted some of the technique’s features, including automated and fast exosome isolation (less than 5 minutes of processing time, compared to approximately 8 hours of processing time using benchmark technologies). Analyses can be performed at relatively low cost and at points of care. Also, it is suitable for repeated and continuous monitoring of tumor progression and treatment—unlike traditional biopsy.
“The acoustofluidic separation technique provides a fast, biocompatible, high-yield, high-purity, label-free method for exosome isolation from saliva.”— David T.W. Wong, DMD, DMSc
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“With these features, the acoustofluidic technology has the potential to significantly exceed current industry standards, address unmet needs in the field, help expedite exosome-related biomedical research, and aid in the discovery of new exosomal biomarkers,” commented Dr. Huang.
“The saliva exosome liquid biopsy is an effective early detection and risk assessment approach for oropharyngeal cancer,” said co-lead investigator David T.W. Wong, DMD, DMSc, of the Center for Oral/Head and Neck Oncology Research, School of Dentistry at the University of California, Los Angeles. “The acoustofluidic separation technique provides a fast, biocompatible, high-yield, high-purity, label-free method for exosome isolation from saliva.” According to the researchers, this technology can also be used to analyze other biofluids such as blood, urine, and plasma.
Disclosure: For full disclosures of the study authors, visit jmdamjpathol.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.