p53 as a prognostic marker associated with the risk of mortality for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is often associated with a poor prognosis. The purpose of the present study was to investigate survival and the risk of mortality in OSCC with regard to stage, tumor site and p53 expression. A retrospective study was performed on 150 non-consecutive cases of OSCC that were observed between January 1992 and January 2012, and were selected from a total of 580 patients according to the criteria of the homogeneity of histopathological grading (G2). The medical records were reviewed for 48 cases with disease at stage I [37 males, age 64.7±5.7 years (mean age±standard deviation); 11 females, age 70.0±3.37 years]; 27 cases with stage II (15 males, age 64.5±5.6 years; 12 females, age 69.2±3.9 years); 58 cases with stage IVa (42 males, age 66.9±5.3 years; 16 females, age 64.2±6.5 years); and 17 cases with stage IVb (16 males, age 65.7±5.4 years; 1 female, age 69 years). Monoclonal p53 antibody (clone DO-7) was used to perform the p53 immunohistochemical study. A significant association was found between the site of the tumor and p53 overexpression (P<0.0001). Stage I-II cases showed a higher cumulative probability of a 24-month survival time than stage IVa-IVb cases (P<0.0001). Cheek, floor and soft palate tumors showed a worse prognosis (P<0.0001) and tumors with p53 overexpression >50% showed a poor survival rate (P<0.0001) compared with tumors of the attached gingiva, tongue and retromolar trigone. The findings allowed the quantification of the risk mortality from OSSC with regard to stage, tumor site and the p53 expression pattern of the tumor. Data supported the absolute indications for wide surgical margins (radical surgery) in cases of T1-T2 N0 tumors of the tongue, floor, retromolar trigone and attached gingiva when p53 overexpression is >50% in association with a higher risk of mortality compared with when p53 overexpression is <50%.