Oral cancer development in lichen planus and related conditions-3.0 evidence level: A systematic review of systematic reviews

A systematic review of systematic reviews-aka overview of reviews, a novel type of study design providing a tertiary level of evidence-is presented on systematic reviews (SR) and meta-analyses (MTA) evaluating the cancer development in oral lichen planus (OLP), oral lichenoid lesions (OLL), and oral lichenoid reactions (OLR). We searched for SR-MTA published before January 2021. We evaluated the methodological quality of SR-MTA using AMSTAR2 and checked the quality of evidence. Inclusion criteria were met by seven SR-MTA. Oral cancer ratios ranged between 0.44% and 2.28% for OLP, between 1.88% and 3.80% for OLL, and 1.71% for OLR. Significant factors on cancer development reported in SR-MTA were the presence of epithelial dysplasia, the consumption of tobacco and alcohol, the infection by the hepatitis C virus, the presence of atrophic and erosive lesions, and the location on the tongue. Only, one of the SRs assessed the quality of evidence, and most of them were judged to be of critically low methodological quality. In conclusion, based on the reported evidence on cancer incidence in OLP, our results reaffirm classifying OLP as an oral potentially malignant disorder. In relation to OLLs and OLRs, larger studies are necessary to provide further scientific evidence in this regard. Future follow-up studies on OLP and related lesions should be carried out under stricter criteria that improve their quality of evidence and methodological quality.

Automated summary

The systematic review found that oral lichen planus, oral lichenoid lesions, and oral lichenoid reactions may be associated with the development of oral cancer, with factors such as epithelial dysplasia, tobacco and alcohol consumption, virus infections, and specific lesions playing significant roles. Most of the systematic reviews evaluated in the study were judged to have critically low methodological quality, highlighting the need for larger and higher quality studies in the future to provide more scientific evidence.