Detection of p16 and p53 in Potentially Malignant Disorders and Oral Squamous Cell Carcinoma

Objectives: To detect p16 and p53 in potentially malignant disorders (PMD) and oral squamous cell carcinoma (OSCC) using immunohistochemistry (IHC).
Methods: A total of 117 formalin-fixed paraffin embedded tissue were selected for OSCC cases (n=46), PMD (n=32), oral epithelial hyperplasia (OEH)(n=31) and normal oral mucosa (NOM) (n=8). the cases were retrieved from the archives of Oral Pathology Department, Faculty of Dentistry, UKM and Institute of Medical Research (IMR), Kuala Lumpur. IHC staining was manually performed using p16 antibody (1:1000 dilution, ABCAM) and p53 ready-to-use antibody (DAKO) following manufacturer's instruction and assessed qualitatively (positivity and staining intensity). Positive and negative controls were used to validate the IHC run. All data were then analysed using SPSS version 22.0 and p values <0.05 were considered significant.
Results: The p16 were found positive in OSCC (97.83%), PMD (84.38%), OEH (83.87%) and only 12.50% in NOM. There is significantly higher of p16 positivity in OSCC compared to NOM (p<0.001). Similarly, there are significant differences in p53 expression between NOM and OSCC (p<0.01) and between PMD and OSCC (p<0.05).
Conclusions: p16 and p53 immunoexpression were increased following the degree of malignancy. The finding suggests that p16 and p53 can be used as a potential marker for oral malignancy detection.