Expression of p53 Protein in Leukoplakia and Oral Squamous Cell Carcinoma
Rahul Khanna, Atul K Vidhyarthi, Seema Khanna, Usha Singh and Umesh C Singh
World Journal of Surgical Medical and Radiation Oncology 2012, 1:16
To evaluate p53 protein expression by immunohistochemistry in oral leukoplakia and squamous cell carcinoma biopsies.
Patients and Methods:
Thirty-two histologically proven oral squamous cell carcinoma, 38 leukoplakia and 20 normal healthy oral mucosal biopsies were included. Half the biopsy specimen underwent conventional histopathological examination and the remaining half was subjected to p53 protein specific immunohistochemistry.
Out of 32 oral cancer biopsies, 11 (34%) showed evidence of p53 protein staining. Of these 8 had grade 2 or unequivocal staining and 3 had grade I or weak staining. Among leukoplakia specimens, 6 out of 38 (16%) demonstrated p53 stain on IHC. Of these, 1 had grade 2 and 5 had grade 1 p53 stain. On histological correlation all 6 leukoplakia specimens positive for p53 had evidence of dysplasia. Out of 32 p53 negative leukoplakia biopsies, only 5 (16%) had dysplasia. Significantly none of 20 normal oral mucosal biopsies took up p53 stain.
Mutation of p53 gene is one of the most common events in oral carcinogenesis. Accumulation of p53 protein has also been detected in premalignant lesions especially oral leukoplakia with dysplasia as was evident in 16% of our leukoplakia biopsies. This suggests that p53 gene mutation may be an early step in the malignant conversion of oral dysplastic lesions. Such patients can be identified by p53 protein specific IHC and subjected to strict follow-up protocol or undergo wide local excision of their dysplastic lesions.