A quick brush of the mouth could soon help spot oral cancer in under an hour.

Scientists from the UK and India have tested a non-invasive oral cancer test called the quantitative Malignancy Index Diagnostic System, or qMIDS, which uses a brush swab of a suspicious lesion and a control sample from an unaffected part of the mouth.

The test then checks for mRNA expression from four specific genes linked to oral cancer.

In the study, brush biopsies were collected from 545 patients with lesions that could potentially be cancerous. The researchers found the test had an overall accuracy of 95.5 percent, with false-positive and false-negative rates of less than 5 percent. Results were available within an hour.

“[This test] gives clinicians a rapid, accurate, and non-invasive way to triage patients, and crucially, it can be repeated,” said Muy-Teck Teh, an oral oncologist at Queen Mary University of London.

“That means we can now monitor patients with persistent pre-malignant lesions regularly and systematically, and pick up cancers much earlier than we would have been able to before.”

Oral cancers usually appear as persistent sores or discolored patches on the lips, gums, tongue or inner cheeks. Many are benign, but checking them often means taking a tissue biopsy with a scalpel.

That can be painful, and some patients need multiple biopsies over time to track how a benign lesion may progress into cancer. The article says many patients opt out of follow-up because the procedure is invasive.

Earlier versions of qMIDS had already shown promise in large-scale trials. For this study, researchers tested a third version to see how well it could distinguish oral cancer from benign lesions.

“We were genuinely astonished by the fact that the brush swab test performance is comparable to a microbiopsy,” Teh said.

“It suggests that the biological signal captured by these four genes is sufficiently strong and consistent that it can be detected even from the superficial exfoliated cells collected by a brush biopsy.”

The researchers said the test could spare low-risk patients unnecessary discomfort and help high-risk patients monitor lesions over time.

Worldwide cases of oral cancer have more than doubled since 1990, and deaths have also more than doubled. The article says smoking, alcohol, sugary drinks and human papillomavirus, or HPV, infections are thought to be linked to the disease.

The researchers are looking to commercialise the test and said it could be available for clinical use in as little as two years. The research was published in Biomarker Research.

Read more from Science Alert.