Expression of mutant p53 in oral squamous cell carcinoma is correlated with the effectiveness of intra-arterial chemotherapy

The aim of the present study was to evaluate the correlation between the positive expression rate of mutant p53 and the clinical characteristics of patients with oral squamous cell carcinoma (OSCC), as well as the effectiveness of intra-arterial chemotherapy. Expression of mutant p53 in tumor tissues was determined by immunohistochemical analysis of 51 OSCC patients, prior to and following intra-arterial chemotherapy. Prior to intra-arterial chemotherapy, mutant p53 positive rates in patients with higher pathological grades were significantly higher than those of the patients with lower pathological grades. The mutant p53 positive rate in patients with lymph node metastasis was 73% (19/26), which was significantly higher than that of the patients without lymph node metastasis (20%, 5/25). Mutant p53 was expressed in 17% (3/18) of clinical phase II patients, while 64% (21/33) of clinical phase III and IV patients exhibited positive expression of mutant p53 (P<0.05). The mutant p53 positive rate in chemotherapy non-responsive patients was 69% (11/16), which was significantly higher than that in the chemotherapy-responsive patients (37%, 13/35). Mutant p53 positive rates were not significantly correlated with age, gender or the location of the tumor. The mutant p53 positive rate prior to chemotherapy was 47% (24/51), and decreased to 18% (9/51) following chemotherapy. Expression of mutant p53 was decreased in all 13 (100%) chemotherapy-responsive patients, while only 5 (45%) chemotherapy non-responsive patients exhibited reduced expression levels of mutant p53 (P<0.05). In conclusion, mutant p53 has a significant role in the differentiation, development and treatment guidance of OSCC. Intra-arterial chemotherapy with 5-fluorourcil and carboplatin potentially exerts a therapeutic effect by reducing the expression of mutant p53.