Malignant transformation in 5071 southern Taiwanese patients with potentially malignant oral mucosal disorders.

Yen-Yun Wang,Yen-Hsuan Tail,Yuk-Kwan Chen,Wen-Chen Wang,Ching-Yi Chen,Yu-Hsun Kao,Chung-Ho Chen

doi:10.1186/1472-6831-14-99

Abstract

BackgroundOral cancers can be preceded by clinically evident oral potentially malignant disorders (OPMDs). The current study evaluated the rate and the time of malignant transformation in the various OPMDs in a cohort of patients from southern Taiwan. Parameters possibly indicative for malignant transformation of OPMDs, such as epidemiological and etiological factors, and clinical and histopathological features were also described.MethodsWe followed-up 5071 patients with OPMDs—epithelial dysplasia with oral submucous fibrosis, epithelial dysplasia with hyperkeratosis/epithelial hyperplasia, hyperkeratosis/epithelial hyperplasia, oral submucous fibrosis, lichen planus, and verrucous hyperplasia—between 2001 and 2010 for malignant transformation.ResultsTwo hundred nineteen of these 5071 OPMD patients (202 men, 17 women; mean age: 51.25 years; range: 30–81 years) developed oral cancers (179 squamous cell carcinomas; 40 verrucous carcinomas) in the same sites as the initial lesions at least 6 months after their initial biopsies. The overall transformation rate was 4.32% (mean duration of transformation: 33.56 months; range: 6–67 months). Additionally, the mean time of malignant transformation was significantly shorter for lesions with than without epithelial dysplasia. The risk of malignant transformation was 1.89 times higher for epithelially dysplastic than non-dysplastic lesions. The anatomical site of OPMD and the presence of epithelial dysplasia were significantly associated with malignant transformation. The hazard rate ratio was 1.87 times larger for tongue lesions than for buccal lesions.ConclusionPatients with OPMDs require long-term follow up.

Highlights

Oral cancers can be preceded by clinically evident oral potentially malignant disorders (OPMDs)
A majority of these OPMD lesions were in the buccal mucosa (60.51%), followed by the gingiva (13.65%), and the tongue (12.46%) (Table 1)
We included a wide spectrum of histopathologically diagnosed OPMDs and specified that the time from the initial presentation of the precancerous lesion to the malignant transformation must be at least six months and that the transformation must occur at the same site as the initial biopsy

Summary

Introduction

Oral cancers can be preceded by clinically evident oral potentially malignant disorders (OPMDs). The current study evaluated the rate and the time of malignant transformation in the various OPMDs in a cohort of patients from southern Taiwan. The claims in recent research that the five-year survival rate of oral cancers is still low might be attributable to most cases of OSCCs being diagnosed at an advanced stage. Because most cases of OSCC are preceded by clinically evident oral potentially malignant disorders (OPMDs), it is important to prevent malignant change for those patients diagnosed with OPMDs [6]. In our review of the English literature, we found only a few studies that focused on the malignant transformation potentials of various OPMDs. Hsue et al [7] found that the malignant transformation rates of a cohort of 1458

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Results

Discussion

Conclusion