Rate of Malignant Transformation Differs Based on Diagnostic Criteria for Oral Lichenoid Conditions: A Systematic Review and Meta-Analysis of 24,277 Patients

Abstract

Objectives: This systematic review and meta-analysis aims to evaluate the evidence on the malignant potential of oral lichenoid conditions (OLCs) including oral lichen planus (OLP), oral lichenoid lesions (OLL), and lichenoid mucositis dysplasia (LMD). In addition, it aims to compare the rate of malignant transformation (MT) in OLP patients diagnosed according to different diagnostic criteria, and to investigate the possible risk factors for OLP MT into OSCC. Materials and methods: A standardized search strategy was applied across four databases (PubMed, Embase, Web of Science, and Scopus). Screening, identification and reporting followed the PRISMA framework. Data on MT were calculated as a pooled proportion (PP), subgroup analyses and possible risk factors for MT were pooled as odds ratios (ORs). Results: Among 54 studies with 24,277 patients, the PP for OLCs MT was 1.07% (95% CI [0.82, 1.32]). The estimated MT rate for OLP, OLL and LMD was 0.94%, 1.95% and 6.31%, respectively. The PP OLP MT rate using the 2003 modified WHO criteria group was lower than that using the non-2003 criteria (0.86%; 95% CI [0.51, 1.22] versus 1.01%; 95% CI [0.67, 1.35]). A higher odds ratio of MT was observed for red OLP lesions (OR = 3.52; 95% CI [2.20, 5.64]), smokers (OR = 1.79; 95% CI [1.02, 3.03]), alcohol consumers (OR = 3.27, 95% CI [1.11, 9.64]) and those infected with HCV (OR = 2.55, 95% CI [1.58, 4.13]), compared to those without these risk factors. Conclusions: OLP and OLL carry a low risk of developing OSCC. MT rates differed based on diagnostic criteria. A higher odds ratio of MT was observed among red OLP lesions, smokers, alcohol consumers, and HCV-positive patients. These findings have implications for practice and policies.

Precursor Lesions, Overdiagnosis, and Oral Cancer: A Critical Review

“…However, OPMDs include a number of clinically heterogeneous conditions, and the malignant transformation rates of individual diseases can vary widely (Table 2). For the OPMDs most commonly studied, the average cumulative transformation rates reported in recent systematic reviews range from 43.87% to 65.8% for PVL [37][38][39], 12.7% (19.9% in the meta-analysis) for erythroplakia [40], 7.20% to 9.8% for leukoplakia [41][42][43], 4.2% to 6% for oral submucous fibrosis [44,45], and 0.44% to 3.80% for oral lichen planus and lichenoid-type disorders [46][47][48], although the latter group is significantly influenced by the diagnostic criteria used [49], particularly the inclusion of dysplasia [50]. These estimates seem to be relatively homogeneous worldwide, including Asian countries, although there are differences reflecting regional risk factors.…”

Oral lichen planus – an oral potentially malignant disorder (OPMD) of the oral cavity

“…Previous prospective and retrospective studies have found a potential for malignant transformation of OLP ranging from 0.07% to 6.5% over observation periods ranging from 0.5 to 22 years [3,5,22,28]. According to WHO data, this figure varies from 0.4% to 12.5%, with an average rate of 1.09% [11,15,16,23,27,30,34,47].…”

“…Therefore, OLP is a potentially malignant condition with a rate of malignant transformation ranging from 0% to 12.5% depending on the follow-up period. Studies have listed the following risk factors for the malignant transformation of OLP: lesion localization on the tongue, the red type (atrophic or erosive form), tobacco and alcohol consumption, and HCV [22,46,47]. The wide range of OLP malignant transformation rates obtained in these analyses can be attributed to differences in the diagnostic criteria used, the average follow-up periods, and the number of cases evaluated [48].…”

Malignant Transformation of Oral Lichen Planus—An Umbrella Study of Systematic Reviews

“…In the latest published systematic review and meta-analysis, Li, J-W et al [18] examined the evidence on the MT of what they termed Oral Lichenoid Conditions (OLCs). Under this umbrella term of OLCs, the authors included OLP, OLL, and what they termed Lichenoid Mucositis Dysplasia (LMD).…”