The Early Detection of Malignant Transformation of Potentially Malignant Disorders: Oral Lichen Planus.

Background: The aim of this study was to evaluate the usefulness of close clinical surveillance intervals combined with oral brush biopsies to enable the early detection of malignant transformations in patients with oral lichen planus (OLP) performed in our oral medicine clinic.

Methods: This retrospective study was carried out on 414 patients suffering from OLP, based on pre-established clinical and histopathological criteria, who received long-term follow-up between 1993-2022 (ranging from 6 months to 22.2 years).

Results: A total of 297 patients were included in this study. Four people developed an oral squamous cell carcinoma (OSCC) during the observation period. Patients with close follow-up intervals were detected at early stages (two cases showed histologically SIN III and one patient was classified as having a pT1N0M0 tumour). One case was dropped in the consultation hour during the COVID19 pandemic and appeared again two years later, staged as a pT3N1M0 tumour based on an OLP. Three of the cases were clinically doubtful, which led to brush biopsies. Afterwards, additional DNA-image cytometry was performed, in which all the specimens of brush biopsies showed aneuploidy as a marker for malignancy, regarding both stem line and single cell aneuploidy.

Conclusions: A careful surveillance programme consisting of check-ups every 3-4 months, oral brush biopsies, and static DNA image cytometry in cytologically diagnosed doubtful or suspicious cases assures the early detection of malignant transformation in the cancer's early intraepithelial and microinvasive stages.