Familial Nasopharyngeal Carcinoma 6

The Epidemiology of Nasopharyngeal Carcinoma 1Jun Ma and Sumei CaoCONTENTS1.1 Introduction 11.2 Regional and Spatial Distribution 11.3 Gender and Age Distribution 21.4 Racial Distribution 21.5 Familial Aggregation 31.6 Time Tendency 31.7 Risk Factors 41.7.1 Epstein–Barr Virus 41.7.2 Salty Fish and Pickled Food 41.7.3 Smoking and Drinking 41.7.4 Effect of Hereditary Susceptibility 51.7.5 Traditional Chinese Medicine 51.7.6 Professional Exposure 51.7.7 Chronic Upper Respiratory Disease 61.7.8 Trace Element 61.8 Summary 6References 61.1IntroductionNasopharyngeal carcinoma (NPC) is a malignanttumor of nasopharyngeal epithelium. It is the maintype in nasopharyngeal malignant tumors in bothendemic areas and regions with low incidence. Epidemiologicalstudies in NPC with the focus on etiologyand biological behavior of the disease werestrongly encouraged as a result of the InternationalUnion against Cancer (UICC) Symposium on Cancerof Nasopharynx held in Singapore in 1964 (Muiret al. 1967), and investigations in the past four decadeshave produced many important findings in thoseaspects. NPC has unique epidemiological features,including obvious regional, racial, and familial aggregation.The aim of this chapter is to detail the incidenceand distribution of NPC, as well as risk factorsof the development of the disease.1.2Regional and Spatial DistributionJun Ma, MDSumei Cao, MDDepartment of Radiation Oncology, Cancer Center of SunYat-sen University, 651 Dongfeng Road, East, Guangzhou,Guangdong 510060, P.R. ChinaNasopharyngeal cancer is a type of tumor withextremely unbalanced endemic distribution. It can beseen in many countries and areas of the five continents.However, the incidence of NPC is lower than1/10 5 in most areas. High-incidence areas are centralizedin the southern part of China (includingHongkong). The highest incidence is found inGuangdong province, and the incidence in male canreach 20–50/100000. According to the data of InternationalAgency for Research on Cancer (IARC),approximately 80,000 cases of NPC were newly diagnosedworldwide in 2002, and about 50,000 casesdeceased, with Chinese accounting for 40%. Intermediaterates were seen in local inhabitants of