Oral cavity carcinoma in patients with and without a history of lichen planus: A comparative analysis

Oral potentially malignant disorders (OPMD) are associated with the risk of malignant transformation (MT) into oral cavity carcinoma (OCC). Oral lichen planus (OLP) is one of the most common OPMDs in western countries. Although there is a substantial amount of research on progression to cancer, a specific analysis of the clinical characteristics and prognosis of cancer developed in patients with a history of OLP versus patients without a history of OLP has not been investigated so far.

Retrospective evaluation of 82 patients treated for OCC with a known history of OLP compared to a representative sample of 82 patients treated for OCC without a known history of LP. Comparative analyses were performed on age at presentation, sex, TNM staging, clinical characteristics, pathology characteristics, 2- and 5-year overall survival (OS), and disease-free survival (DFS).

It was shown that patients with a history of LP were significantly younger at first presentation than patients without a history of LP (mean age difference 6.7 years, 95% CI 3.1-10.3, p < 0.05). Also, patients with a history of OLP were in higher proportion females. The main pathological stage at presentation was significantly lower in the OLP group (p < 0.05). The 2-year survival analysis showed that DFS and OS were significantly lower in patients without a known history of OLP, with a hazard ratio (HR) of 3.1 (95% CI 1.4-6.8) and HR of 2.6 (95% CI 1.3-5.3), respectively. The 5-year survival analysis showed that DFS and OS were significantly lower in patients without a known history of OLP, with a hazard ratio of 3.1 (95% CI 1.6-6.2) and of 2.9 (95% CI 1.5-5.6), respectively.

Cancer arising from OLP has peculiar characteristics compared to cancer in naïve patients. It most commonly affects younger patients, women, and nonsmokers. It is usually diagnosed at earlier stages and appears to have less aggressive behavior at presentation. Moreover, when 2- and 5-year survival is analyzed, it appears that patients in OLP group have an overall and a disease-free survival advantage. These results suggest that cancer from OLP is less aggressive and thus has a potential biological difference with cancer arising in non-OLP patients. Further clinical and basic investigations are needed to confirm the results of this study.