Nasopharyngeal Carcinoma Characteristics in Portugal

Abstract

Objective: 1) Learn the histologicdistribution of nasopharyngeal carcinoma (NPC) in a nonendemic European country. 2) Learn epidemiological data of NPC in a nonendemic European country. 3) Understand the implications of some genetic polymorphisms on NPC development. Method: Using data collected from a retrospective study of 320 NPC patients obtained at the Oporto Portuguese Institute of Oncology during 31 years, a study is made concerning histological characterization, median age, gender profiles, NPC-EBV relationship, and relevance of concerned genetic polymorphisms on probability of disease and age of onset. Results: A total of 300 out of 320 patients had nonkeratinizing carcinomas (93.75%), with a mean age of 48 years old and twofold male preponderance. Using PCR analysis, EBV-DNA was found in 91.7% of 36 tumor tissue samples. Regarding genetic polymorphisms, 2 case-control studies were performed, including 104 patients and 285 control individuals. TP53 codon 72 pro/pro genotype ( P = .012; OR = 2.67; 95% CI 1.21-5.90) and A870G cyclin D1 GG genotype ( P = .016; OR = 2.09; 95% CI 1.15-3.79) were associated with increased risk for NPC development. Moreover, cyclin D1 GG genotype was also correlated with earlier disease onset. Conclusion: The high relative proportion of nonkeratinizing carcinomas is a relevant finding in this nonendemic European country, and so is the association of EBV-DNA with NPC. This study may help to understand the biologic mechanisms of NPC and the correlation of EBV infection with disease in a low-risk nonendemic region.