A new non-invasive diagnostic test for oral cancer test developed by researchers at the University of Surrey is said to be over 92% accurate at detecting oral squamous cell carcinoma (OSCC) and more than 80% accurate at identifying pre-cancerous oral epithelial dysplasia (OED), according to a proof-of-concept study.
The news comes in the wake of a recent report showing that cases of oral cancer in the UK increased by 34% over the last decade and have more than doubled compared with 20 years ago.
The State of mouth cancer UK report 2022, released last November by the Oral Health Foundation, showed that there were 8846 new cases of mouth cancer diagnosed in the UK over the previous year, with 3034 deaths from the disease.
Earlier Diagnosis Could Reduce Mortality
The researchers noted that "delays in the identification and referral of oral cancer remain frequent" and that an accurate and non-invasive diagnostic test that could be performed in primary care might help to identify oral cancer at an early stage, helping to reduce mortality.
Their proof-of-concept experimental study, dubbed PANDORA (Point-of-care Analysis for Non-invasive Diagnosis of Oral cancer), aimed to assess a machine called a DEPtech 3DEP analyser to identify the set-up, or range of set-ups, that would maximise its diagnostic accuracy. They used the machine to measure and analyse non-invasive brush biopsy cell samples taken in dental surgeries from 40 patients with histologically proven OSCC or OED, and compared the results with samples from 79 controls without cancer (including those with other, benign lesions).
They reported that sensitivity of the index test was 86.8% (95% CI 71.9% to 95.6%) and specificity 83.6% (95% CI 73.0% to 91.2%). Analysing OSCC samples separately led to higher diagnostic accuracy, with 92.0% (95% CI 74.0% to 99.0%) sensitivity and 94.5% (95% CI, 86.6% to 98.5%) specificity.
Test Could be Used in Primary Care
The test could pave the way for better oral cancer detection, the researchers said. The samples were collected in dental surgeries and mailed to their laboratory for analysis, which demonstrated that the test could be "used in primary care to identify patients in need of specialist care".
Study co-author Dr Fatima Labeed, senior lecturer in human biology from the University of Surrey, said: "Over 300,000 people are diagnosed with oral cancer worldwide – a disease with an alarming mortality rate of around 50%. This suggests that the scientific community doesn't have the tools available to identify oral cancer early enough, and we hope that PANDORA paves the way for more effective clinical diagnostic tools for this terrible disease."
According to the NHS, oral cancers most often arise on the tongue, buccal membranes, palate, lips or gums, and less commonly in the salivary glands, tonsils, and pharynx. OSCC is the most common type and accounts for 90% of cases. Oral cancer represents about 1 in every 50 cancers diagnosed, and over two-thirds develop in adults over the age of 55, with fewer than 1 in 8 (12.5%) in people younger than 50. The three most common causes are smoking or other tobacco use, alcohol, and human papillomavirus (HPV) infection, the latter linked with most cases in younger people.
Many Patients Have Locally Advanced Disease at Presentation
If oral cancer is diagnosed early, a complete cure is often possible in up to 9 in 10 cases using surgery alone. However overall 5-year survival rates are only around 60%.
"Advanced cancer stage at time of diagnosis is one of the main factors accounting for the high mortality and morbidity of oral cancer," the researchers said, and this was "despite the accessibility of the oral mucosa to clinical inspection" because "a significant majority of patients present with locally advanced disease".
They concluded that the PANDORA results suggested that "the 3DEP has the potential to identify OSCC and OED with significant and clinically beneficial diagnostic accuracy". The test "warrants further investigation as a potential triage test in the primary care setting" for patients who present with visible oral mucosa lesions suspicious for OSCC/OED and may need to progress to surgical biopsy. Their study paved the way for further clinical validation studies, they said.
Asked to comment by Medscape News UK, Dr Hanya Mahmood, scientific adviser to the British Dental Association, welcomed the idea of a non-invasive test though noted that further clinical testing would be required. He said: "Dentists are often at the forefront of picking up oral cancers as they routinely screen patients for these. As for all cancers, the earlier these are detected the better the prognosis.
"Developments of non-invasive techniques to aid in this diagnosis would be welcome, but as the authors of the study acknowledge, their findings are preliminary, and it is much too early to say how effective this test would be in the real-world population. We have yet to see the clinical utility of the proposed technology over the current gold standard.
"The diagnosis of oral pre-cancer is notoriously complex and subjective, even using conventional histopathological methods, and we look forward to seeing whether further clinical testing of this tool validates its diagnostic performance and accuracy."
PANDORA received funding from the NIHR Invention for Innovation(i4i) Programme (grant reference: ES-1010-10163) and infrastructure funding from the NIHR UCLH Biomedical Research Centre. The study was sponsored by the UCL/UCLH and Royal Free Joint Research Unit. MP Hughes and KF Hoettges are directors of DEPtech, which manufactured the 3DEP instrument used in the experiments. The other authors declare no conflicts of interest.