p53 and p16 in oral epithelial dysplasia and oral squamous cell carcinoma: A study of 208 cases.

ABSTRACT

Background: The use of p16 and p53 as biomarkers of malignant transformation of oral epithelial dysplasia (OED) and biological behavior of oral squamous cell carcinoma (OSCC) is controversial. Aim: To determine the immunoexpression of p16 and p53 in OED and OSCC and to establish their possible relation to histopathological grading of OED/OSCC. Materials and Methods: Ninety‑six OEDs (40 mild, 36 moderate, and 20 severe dysplasia); and 112 OSCCs (64 well‑differentiated, 38 moderately differentiated, and 10 poorly differentiated) coming from archives of four centers of oral pathology were included. Histological slides from all cases were processed with immunohistochemical technique using anti‑p53 and anti‑p16 antibodies. The intensity of the immunoreactivity were classified using the ImageLab®MCM systemas follows <60 mild, >60–<90 moderate, and >90 strong. Forstatistical purposesa χ2 test (P < 0.05) was performed. Results: Severe dysplasia show highest relative frequency of p16‑positive (35.5%), whereas p53 is associated with mild dysplasia (P = 0.04). Moderately differentiated OSCC had larger relative frequency of p16‑positive and p53‑positive cases (47.3% both circumstances) (P > 0.05). Statistical association of p16‑positive and p53‑positive cells to basal stratum of OED (P = 0.0008; P = 0.0000, respectively) and p16‑positive cells and p53‑positive cells to perivascular zone of OSCC (P = 0.001; P = 0.0000, respectively) was found. Conclusions: p16 and p53 could be not specific enough to identify patients suffering OED with high risk to malignancy; however, the evaluation of the presence of p16 and p53 in the tumoral invasive front of OSCC could contribute to establish the tumor progression.