Main

Gandolfo S, Richiardi L et al. Oral Oncol 2004; 40: 77–83

A recent review concluded that there is not enough evidence to conclude that lichen planus is a premalignant lesion. In this study, 402 patients (27% smokers) with OLP diagnosed by Krutchkoff's criteria in the main Turin hospital from 1988 to mid-1999 were seen about once per yr until early 2001, death, or diagnosis of oral SCC. Latency of 6 months from OLP diagnosis was allowed before counting an SCC diagnosis.

Comparison with the local cancer registry's oral statistics gave an expected 0.2 tumour cases in the sample, but 9 were found (P < 0.05 in both men [2] and women [7]), including a verrucous carcinoma. Non-smokers accounted for 5 cases, including this one. When latency of 2 yrs was applied, the proportion developing OLP decreased from 0.0223 to 0.0113 (355 subjects, 4 tumours v. 0.15 expected). The authors discuss possible confounders, including lesions which might have been already dysplastic, diagnostic variation, synchronous OLP and SCC, Candida, HCV infection and the role of smoking.