P53 overexpression in epidermoid carcinoma of the head and neck

Abstract

The theory of field cancerization in tumors of the head and neck reflects the complex oncogenesis that occurs in this region. The mechanisms that control cell proliferation at the molecular levei in epidermoid carcinomas (ECs) of the upper aerodigestive tract are still unclear. Mutations in p53 are the genetic alterations most often detected in ECs of the head and neck and seem to contribute actively to the carcinogenic process triggered by p53 as a tumor-suppressor gene and to its association with tobacco. The objective of the present study was to investigate the expression of p53 protein in epidermoid head and neck carcinomas by immunohistochemistry and its immunohistochemical correlation with other prognostic factors. The study was conducted on 63 consecutive ECs cases not submitted to previous treatment. Specimens of the tumor and of the normal adjacent mucosa were collected during surgery and submitted to immunohistochemical reaction for the determination of the expression of anti-protein p53 antibody (M7001 DAKO AIS, Denmark). Anatomo-c1inical and demographic data were not significantly correlated with the presence of Iymph node metastases or p53 expression in the tumor or in the adjacent normal mucosa. Tumor localization in the larynx was significantly correlated with p53 expression. Histological grading as grades I, 11, 111 and IV was correlated with significant p53 expression (p = 0.025). Conclusions: 1) in the studied material obtained from 63 cases of head and neck ECs, we detected a 48 percent rate of immunohistochemically detectable p53 overexpression; 2) we did not detect a relationship between demographic patient data and p53 expression in the tumor or in the normal adjacent mucosa; 3) p53 overexpression was significantly more frequent in ECs material from the larynx; and 4) The presence of 12 cases with p53 overexpression in the normal adjacent mucosa and with a p53-negative tumor is in agreement with the theory of field cancerization. Follow-up of this patient series for a longe r period of time will permit a better analysis of these values. UNITERMS: P53, squamous cell carcinoma, head and neck cancer, immunohistochemistry INTRODUCTION E Pidermoid carcinomas (ECs) represent more than 90 percent of the neoplasias of the upper aerodigestive trace) and their incidence increases among subjects who smoke cigarettes and consume alcoholic beverages. 12ECs correspond to the sixth most frequent form of cancer in the worldY

Ki-67 expression score correlates to survival rate in gastrointestinal stromal tumors (GIST)

“…The evaluation of cell cycle-related proteins in neoplasms by immunohistochemistry has been included in prognostic staging in central nervous system 25,26 and other tumors 21,[27][28][29][30] . We verified if these same proteins could also play a prognostic role in GIST 20,31 .…”