ASCO 2016: Saliva Test May Replace Biopsy for Some Lung Cancer Patients

An emerging field in medicine, salivary diagnostics, may be the next step in detecting treatable cancer mutations in lung cancer. Researchers from the University of California Los Angeles (UCLA) School of Dentistry and collaborators from MD Anderson Cancer Center performed a double-blind study on 37 people who were diagnosed with non-small cell lung cancer (NSCLC) at three lung cancer centers in Chengdu, China.

These study results were presented at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 3-7, 2016, in Chicago (abstract 8520).

For each patient, the research team collected pre- and post-biopsy tissue and saliva cells samples. The researchers began by cataloging the biopsied plasma lung cells using digital polymerase chain reaction (dPCR). Next, the team cataloged the saliva cells using a proprietary UCLA-developed technology, called electric field-induced release and measurement (EFIRM) liquid biopsy, to see whether they could detect the same mutations as they did with the plasma cells. They were looking for epidermal growth factor receptor (EGFR) mutations, specifically receptor L858R and exon 19del.

“This study has confirmed the performance of EFIRM liquid biopsy using as little as 40 microliters of saliva for detecting EGFR mutations,” said David Wong, DMD, DMSc, lead author on the study and the associate dean for research at the UCLA School of Dentistry, in a news release. “We are confident that EFIRM liquid biopsy is just as effective at detecting cancer mutations as the current dPCR method of testing tissue.

Collecting and analyzing saliva appears to be an inexpensive method in the early detection of many types of cancer. Lung cancer patients can particularly benefit from this method as lung cancer tends to be diagnosed in advanced stages and may be mistaken for other medical issues.

Lung cancer is the leading cause of cancer deaths worldwide, according to the World Health Organization. In the United States alone, there are projected to be 225,000 new cases diagnosed this year. At increasing rates, lung cancer is being diagnosed in women and in Asian countries where the frequency of cancer mutations is three times higher.

Although lung biopsy has been the traditional method of detection, this less invasive method may benefit those medically fragile such as older patients.