Cancer screening is commonly associated with a tedious series of blood exams and imaging tests. Such process may possibly change soon, thanks to a 10-minute saliva test that can detect cancer with near-perfect accuracy.
Experts say the test is so reliable and simple that it can be performed at the pharmacy, at the dentist or even in the comforts of a patient's home.
Detecting Circulating Tumor DNA
Researchers from the University of California, Los Angeles, led by David Wong, have been creating a technique that can detect tumor DNA circulating in body fluids, such as in the blood or saliva.
Dubbed liquid biopsy, this method is said to provide a quick, convenient and less invasive option to detect cancer early and ascertain the disease's state during treatment.
The researchers presented their work at the 2016 American Association for The Advancement of Science, where Wong described a prototype tool that can identify biomarkers in saliva for a type of malignancy.
The device called electric field-induced release and measurement (EFIRM) is more efficient than the existing sequencing technology and is set to be clinically tested this year on patients diagnosed with lung cancer in China.
The Saliva Test
All it needs is one drop of saliva, Wong says. He adds that the test may be completed in just 10 minutes.
Wong says the test may be combined with other diagnostic modalities depending on the disease. For example, if a patient's chest x-ray shows a suspicious lump, then doctors may opt to do the saliva test to determine if cancer may be present.
Detecting Various Types Of Cancer
Wong and colleagues have particularly been studying the use of saliva-based tests in detecting mutations connected to several mouth and throat cancers.
"Right now, there are not effective screening modalities to detect human papillomavirus-related oropharyngeal cancers early," says Gypsyamber D'Souza from Johns Hopkins University.
She says the complexity of each cancer process and the possible help of liquid biopsy must be considered prior to getting all too excited.
For example, D'Souza says HPV may take about 10 years to advance to oral cancer. Also, the virus may have been cleared up within a year or two. She cautions people about the possible anxiety that the test may create if markers of HPV-related cancers are detected. Just having the virus in the mouth is a bad indicator that a person will go and develop cancer.
So far, the scientists have detected "signature mutations" that may be responsible for approximately 80 percent of HPV associated with mouth and throat cancers. Wong says being able to detect these mutations via the saliva test may pave the way for early treatment of cancers that have five-year survival rate of about 60 percent.