The malignant transformation rate of erosive oral lichen planus - a retrospective study

Oral lichen planus is a chronic inflammatory oral condition previously known to have a rate of malignant transformation of around 1%[1]. Additionally, erosive lichen planus, a subtype of lichen planus which is a known risk factor for malignant transformation, has been previously unquantified in a large cohort of patients.

We retrospectively assessed 1,920 patients in a single unit observation between 2005 and 2021 who underwent histological analysis for suspected oral lichen planus and followed the progression of their disease to assess the rate of malignant transformation. 1.39% of oral lichen planus transformed to oral squamous cell carcinoma over an average of 5.8 years. We found the transformation rate of erosive oral lichen planus into malignancy however was 5.98% with aggressive clinical pathway.

The incidence of erosive OLP has not previously been quantified in a large cohort of patients, this retrospective study sheds light and raises warning signs to the seriousness of this condition.