Prevalence of precancerous lesions and conditions in India: A systematic review and meta-analysis

BACKGROUND: Smoking and chewing tobacco are associated with numerous oral mucosal lesions and conditions, often leading to cancer progression. AIM: To investigate the prevalence of precancerous lesions and conditions among the Indian population. METHODS: Systematic search was conducted for population or community-based observational epidemiological studies in PubMed, EMBASE, Web of Science, IndMED, Google Scholar, reports of the WHO South-East Asia Region, MOHFW India reports, Science Citation Index, WHO Index Medicus of the South-East Asian Region, Reference Citation Analysis (https://www.referencecitationanalysis.com/) and Open Grey from the earliest available up to 31(st) January 2022. The effect size was calculated for the prevalence of precancerous lesions and conditions. RESULTS: One hundred sixty-two estimates from 130 studies yielded 52 high, 71 moderate, and seven low-quality studies from 823845. Point estimate based on cross-sectional studies for leukoplakia was 4.3% (95%CI: 4.0-4.6), oral submucous fibrosis was 2.7% (95%CI: 2.5-3.0), palatal lesions in reverse smokers and nicotine palatine were 5.8% (95%CI: 4.4-7.2), and Erythroplakia was 1.2% (95%CI: 0.7-1.7), and lichen planus was 1.1% (95%CI: 0.9-1.2). Amongst hospital-based studies, the pooled prevalence for Leukoplakia was 6.7% (95%CI: 6.0-7.3), oral submucous fibrosis was 4.5% (95%CI: 4.2-4.9), lichen planus was 7.5% (95%CI: 5.3-9.6), and erythroplakia was 2.5% (95%CI: 0.4-4.5), and palatal lesions in reverse smokers and nicotine palatini were 11.5% (95%CI: 8.0-15.0). CONCLUSION: Precancerous lesions and conditions are prevailing problems among the Indian population. It is mainly due to tobacco use, the smokeless form of tobacco. The meta-analysis indicates that hospital-based studies have a higher effect size of 6.7% than community-based studies. Patients who have already developed this condition may be advised to reduce their exposure to the risk factor to prevent the condition from progressing further.