Oral cancer is one of the most common cancers in males worldwide with oral squamous cell carcinoma (OSCC) being the most frequent neoplasm of the oral cavity.  As survival rates are low early diagnosis is important and a number of chronic conditions including oral leukoplakia (OL), oral erythroplakia (OE), oral submucous fibrosis (OSMF), oral lichen planus (OLP), and actinic cheilitis (AC) may proceed OSCC and a referred to as oral potentially malignant disorders. However, the main associated factors are tobacco and alcohol use.

The aim of this systematic review was to assess the prevalence of oral potentially malignant disorders (OPMD)

Methods

Searches were conducted in the Latin American and Caribbean Health Sciences (LILACS), LIVIVO, PubMed/Medline, Science Direct, Web of Science, Google Scholar, Open Gray, and ProQuest database. Observational studies in adults over the age on 18 where OPMD was clinical diagnosed and histologically confirmed were considered. Two reviewers independently selected studies and abstracted data. Risk of bias was assessed independently by 2 reviewers using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data.  h.A random-effects meta-analysis and sensitivity analysis were conducted. The main outcome was the prevalence of OPMD expressed as a percentage.

Results

• 22 studies were included
• 7 studies were from South America/Caribbean; 5 from Asia; 5 Europe; 2 Middle East; 2 North America.
• 6 studies had sample sizes of lower than 1000 with 4 studies having a sample size of more than 50,000.
• 7 studies were considered to have a high risk of bias; 12 a moderate risk and 3 a low risk of bias.
• The pooled prevalence of OPMD in this study was 4.47% (95% CI = 2.43-7.08) with the  highest prevalence being found in Asian populations.

	Pooled prevalence %	95% CI
OPMD	4.47%	2.43-7.08
Oral submucous fibrosis	4.96%	2.28-8.62
Oral leukoplakia	4.11%	1.98-6.97
Homogeneous oral leukoplakia	1.98%	0.44-4.61
Non- homogeneous oral leukoplakia	0.16%	0.08-0.27
Oral erythroplakia	0.17%	0.07-0.32
Actinic cheilitis	2.08%	0.94-3.67

 

	No of Studies	Prevalence of OPMD%	95% CI
Asian populations	5	10.54%;	4.60-18.55
South America and the Caribbean	7	3.93%	2.43-5.77
Middle East	2	3.72%	2.91-4.67
Europe	5	3.07%	1.64-4.93
North America	2	0.11%,	0.004-0.37

Conclusions

The authors concluded: –

The overall prevalence of OPMD in this study was 4.47% (95% CI = 2.43-7.08). The prevalence of OSMF was 4.96% (95% CI = 2.28-8.62); OL 4.11% (95% CI = 1.98-6.97); AC 2.08% (95% CI = 0.94-3.67); and OE 0.17% (95% CI = 0.07-0.32). Males were more affected by OPMD than females. Differences in the prevalence among populations were also noticed; Asian populations had the highest prevalence of OPMD, which was 10.54% (95% CI = 4.60-18.55). South American and Caribbean populations were also highly affected by OPMD (3.93%; 95% CI = 2.43-5.77).

Comments

As the authors note in their discussion the decision to focus on studies with a histological diagnosis has implications for the findings. This decision means that the data is derived from a diagnostic population-based sample rather than a broader population-based sample, with the risk of bias assessment noting that only 2 of the included studies was representative of the overall target population.  The trade-off being greater clarity on lesion diagnosis against the likelihood of overestimating the true population prevalence. The other point raised by the review authors is in relation to the differing prevalence in different geographical areas which is likely to be as a result of differing risk habits eg the use of betel quid products in South Asia.

Links

Primary Paper

Mello FW, Miguel AFP, Dutra KL, Porporatti AL, Warnakulasuriya S, Guerra ENS, Rivero ERC. Prevalence of oral potentially malignant disorders: A systematic review and meta-analysis. J Oral Pathol Med. 2018 May 8. doi: 10.1111/jop.12726. [Epub ahead of print] Review. PubMed PMID: 29738071.

Original review Protocol on PROSPERO

Other references

Dental Elf Blogs on Oral Potentially malignant lesions

Photo Credits

By Photo uploaded by: dozenist. – Photo taken by Michael Gaither, and he has agreed to release this picture with the following license., CC BY-SA 3.0