Oral submucous is a chronic oral mucosal disease that is one of a group of conditions recognised as oral potentially malignant disorders (OPMD). The prevalence of oral submucous fibrosis is estimated to be between 2.3% to 8.6% with a recent review (Dental Elf – 12th Dec 2022) estimating a malignant transformation rate of 6% (95%CI: 2- 10%).
This umbrella review of systematic reviews aimed to determine the proportion of oral cancer development in oral submucous fibrosis patients.
Searches were conducted in the Cochrane library, PubMed, Scopus and Web of science databases with no language restrictions. Systematic review with or without meta-analyses evaluating malignant transformation in oral submucous fibrosis (OSF) patients were considered. Two reviewers independently screened and selected studies and extracted data. Study quality was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR 2 ). A narrative summary was provided.
- 4 systematic reviews were included.
- Review sample sizes ranged from 4 studies 3986 patients to 16 studies 8516 patients.
- 3 reviews had registered protocols on PROSPERO.
- All 4 reviews undertook meta-analyses.
- Two reviews were considered to be of high quality and 2 of critically low quality using the AMASTAR 2 tool.
- Mean values for malignant transformation for the 4 included reviews ranged from 4.2% to 6% (see table below).
|Publication||No. of studies (patients)||% Malignant transformation (95%CI) *|
|Murthy V et al 2022||16 (8516)||6% (2% to 10%)|
|Nayanar et al 2022||10 (5428)||5.5% (3.9% to 7.2%)|
|Kujan O et al 2021||9 (6337)||4.2% (2.7% to 5.6%)|
|Iocca O et al 2019||4 (3986)||5.2% (99% CI: 2.9% to 8.0%)|
*Unless where indicated
The authors concluded: –
There is lack of quality of evidence and critically low methodological quality among systematic reviews (SRs) and meta-analyses, leading to substantial heterogeneity. The results suggest the estimated rates of malignant transformation (MT) varied widely across the included SRs due to differences in study designs and definitions of OSF. Risk factors associated with MT may include the duration and severity of the disease, the presence of epithelial dysplasia and tobacco use.
No protocol was registered for this umbrella review. Searches were conducted in 4 major databases with no language restrictions. Only 4 reviews were included and while they were published over a short time scale 2019 to 2022 there was a wide variation in the number of included studies, from 2 to 16. We looked at the most recent review by Murthy et al., in a previous blog (Dental Elf – 12th Dec 2022) where we also published a table summarising the malignant transformation data for the 4 reviews included in this umbrella review. The authors indicate that the quality of evidence was not assessed in any of the included papers, although the Murthy review did use the Newcastle-Ottawa scale to quality and included a table of their assessments.
This umbrella review helpfully pulls together the data from 4 earlier reviews and includes a useful discussion sectio. However, it would have been helpful if the authors had also assessed the degree of overlap of studies across the included reviews. This overview and the original systematic reviews highlight a number of issues with the quality of the primary studies. Well designed and reported long-term prospective studies are needed to clarify malignant transformation rates in patients with submucous fibrosis.
Gondivkar SM, Yuwanati M, Sarode SC, Gadbail AR, Gondivkar R, Mohsin SF, Gaikwad R. Malignant transformation in oral submucous fibrosis: Tertiary level evidence: An umbrella review. Oral Dis. 2023 Aug 31. doi: 10.1111/odi.14718. Epub ahead of print. PMID: 37650364.
Dental Elf – 12th Dec 2022
Murthy V, Mylonas P, Carey B, Yogarajah S, Farnell D, Addison O, Cook R, Escudier M, Diniz-Freitas M, Limeres J, Monteiro L, Silva L, Fricain JC, Catros S, Fenelon M, Lodi G, Lombardi N, Brailo V, Ariyaratnam R, López-López J, Albuquerque R. Malignant Transformation Rate of Oral Submucous Fibrosis: A Systematic Review and Meta-Analysis. J Clin Med. 2022 Mar 24;11(7):1793. doi: 10.3390/jcm11071793. PMID: 35407401; PMCID: PMC8999767.
Nayanar, G, Reddy, MGS, Kakodkar, P & Dony, EC Malignant transformation rate of oral submucous fibrosis: A systematic review and meta-analysis. Oral Surg. 2022; 00: 1– 8. https://doi.org/10.1111/ors.12771
Kujan O, Mello FW, Warnakulasuriya S. Malignant transformation of oral submucous fibrosis: A systematic review and meta-analysis. Oral Dis. 2021 Nov;27(8):1936-1946. doi: 10.1111/odi.13727. Epub 2020 Dec 9. PMID: 33205543.
Iocca O, Sollecito TP, Alawi F, Weinstein GS, Newman JG, De Virgilio A, Di Maio P, Spriano G, Pardiñas López S, Shanti RM. Potentially malignant disorders of the oral cavity and oral dysplasia: A systematic review and meta-analysis of malignant transformation rate by subtype. Head Neck. 2020 Mar;42(3):539-555. doi: 10.1002/hed.26006. Epub 2019 Dec 5. PMID: 31803979.