Oral Cancer: Early Detection and Diagnosis. What is oral cancer?

Oral cancer is a potentially fatal disease which dental healthcare professionals may encounter in their clinical practice. Although they are not usually directly involved in the specific therapeutic phase, the role of the dentist and the dental hygienist is fundamental in the prevention of oral cancer, in its early detection, and in managing the side effects caused by oncological therapies.

It is extremely important to acquire adequate knowledge regarding epidemiology, etiology, natural history, clinical manifestations, therapeutic and rehabilitative techniques, as well as the principles and methods useful for the early diagnosis and prevention of oral cancer.

Despite advances in medicine over recent decades, the stage of the disease at the time of diagnosis has not significantly changed. Even with the adoption of the most modern combined therapeutic strategies, the overall survival rate for patients affected by oral cancer does not exceed sixty percent and has not improved significantly, unlike what has been observed for other malignant tumors. The recent COVID-19 pandemic has further reduced access to healthcare facilities and professionals, causing delays in both diagnosis and early treatment of this serious oral disease.

Epidemiological data highlight that early-stage diagnosis of oral cancer is essential to improve patient survival and reduce mortality.

How does oral cancer manifest?

In the early stages, oral cancer often causes no symptoms; sometimes, however, it presents as an area of persistent burning or pain.

Local lesions may vary and appear as white or red patches, areas of abnormal tissue growth, or persistent ulcers.

In advanced stages, infiltration of the surrounding tissues causes pain and difficulty in chewing, swallowing, or speaking.

Most frequently, oral cancer is located on the lateral borders of the tongue and the floor of the mouth. Less frequent sites include the retromolar trigone, gingiva, buccal mucosa, and palate.

How to diagnose oral cancer?

Since the clinical presentation of oral cancer is not specific, a realistic possibility of achieving early detection and diagnosis lies in promptly planning an appropriate diagnostic pathway for all patients presenting with any lesion of the oral mucosa.

The 14-Day Rule

The World Health Organization and other bodies and associations in the field have long recommended that all lesions of the oral mucosa that do not regress spontaneously or with the removal of local irritants within 14 days be considered potentially malignant and subjected to diagnostic assessment. Such assessment consists of instrumental examinations that allow for an accurate classification of the disease presented by the patient.

In clinical practice, the diagnostic test that is currently required in the vast majority of cases is the histopathological examination of the lesion, or of a fragment of it, after biopsy sampling.

The use of auxiliary methods for identifying potentially premalignant or malignant lesions helps improve the detection of areas and lesions of the oral mucosa that should be monitored, referred to a specialist, or selected for biopsy. Among these, the following have proven useful:

• Vital staining with toluidine blue, which selectively stains in dark blue the areas of the oral mucosa showing malignant or dysplastic neoplastic alterations. The dye is selective for DNA content and therefore highlights sites with active cell replication;
• Detection of tissue autofluorescence (OFI). Dysplastic and neoplastic changes in the oral mucosa cause a reduction or disappearance of the normal fluorescent image of the tissue, visible after excitation with blue-violet light. The lesion areas of the mucosa thus appear dark and well-defined against the background of oral tissues that emit an intense green fluorescent light.

These auxiliary tests have been proposed as screening tools with high specificity and lower sensitivity for high-risk individuals and/or for the planning of incisional biopsy sampling in cases of extensive lesions.