New York :
Researchers have developed a new non-invasive method to analyse saliva for the presence of the human papilloma virus (HPV) which is associated with cancers of the mouth and throat. The study, published in the Journal of Molecular Diagnostics, noted that the novel technique detected oropharyngeal cancers (OPCs) in whole saliva in 40 per cent of patients tested, and in 80 per cent of confirmed OPC patients.
The researchers, including those from Duke University in the US, said these cancers, which occur in the back of the mouth and upper throat, are often not diagnosed until they become advanced.
They said this is because their location makes it difficult to detect them during routine clinical exams.
"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," said study co-author Tony Jun Huang.
The scientists said the technique may also help physicians predict which patients will respond well to radiation therapy, or achieve longer progression-free survival.
In the current study, they analysed saliva samples from 10 patients diagnosed with HPV-OPC using traditional methods.
The new method made use of the properties of tiny protein packages in the cells called exosomes. They said these tiny microvesicles originating within cells, are secreted into body fluids.
According to the researchers, the exosomes are believed to play a role in intercellular communication and their numbers are elevated in association with several types of cancers.
To analyse the vescicles, the researchers used a technique called Acoustofluidics -- an advanced technology that fuses the study of sound and fluids. The fluid samples were analyzed using a tiny acoustofluidic chip developed to isolate salivary exosomes by removing unwanted particles based on size.
This left behind exosome-rich concentrated samples that make it easier to detect tumor-specific biomarkers.
The researchers found that the new test identified the tumor biomarker HPV-16 DNA in 80 percent of the cases when coupled with another method called droplet digit PCR.
Since this method is independent of sample variability that arises due to changes in saliva viscosity, and collection methods used, the researchers said, it may prove ideal for use in clinical settings.
"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," Huang said.