A large proportion of esophageal cancer cases and the incidence difference between regions are attributable to lifestyle risk factors in China Ming Wu a , Pieter van’t Veer b , Zuo-Feng Zhang c , Xu-Shan Wang d , Xiao-Ping Gu e , Ren-Qiang Han a , Jie Yang a , Xiao-Feng Zhang d , Ai-Min Liu e , Frans J. Kok b , Ellen Kampman b , Jin-Kou Zhao a,⇑ a Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu, China b Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands c Department of Epidemiology, School of Public Health, University of California, Los Angeles, CA, United States d Ganyu Center for Disease Control and Prevention, Ganyu, Jiangsu, China e Dafeng Center for Disease Control and Prevention, Dafeng, Jiangsu, China article info Article history: Received 18 February 2011 Received in revised form 3 May 2011 Accepted 5 May 2011 Keywords: Esophageal cancer Lifestyle Population attributable fraction Relative attributable risk China abstract A population-based case-control study was conducted in a high-risk area (Dafeng) and a low-risk area (Ganyu) of Jiangsu province, China. In this analysis, the population attribut- able fraction (PAF) was calculated to quantify the etiology of risk factors; the relative attributable risk (RAR) was applied to explore how much of the incidence difference could be explained by variations in the distribution of risk factors. Results showed that unhealthy lifestyles accounted for a high fraction of esophageal cancer in China. Dissimilar distribu- tion of several lifestyle factors, together with hereditary variations may be largely respon- sible for the incidence difference between areas. Ó 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Esophageal cancer is one of the most common cancers worldwide [1]. Although the combination of screening and treatment is increasingly effective in reducing the mortality of this disease nowadays, survival rate is still very low, especially in developing countries [1]. Therefore, primary prevention through lifestyle interventions might stands for a good option for reducing the risk of esophageal cancer. Many studies have been conducted to evaluate the role of lifestyle factors in the etiology of esophageal cancer. Extensive epidemiologic evidence shows that tobacco and alcohol use are major risk factors especially in Western counties [2–4]. Dietary factors are also important in esoph- ageal carcinogenesis. Increased risks are associated with low intake of vegetables and fruits, high intake of carcino- gens from pickled vegetables and fried foods, and injuries of esophageal mucosa e.g., fast eating speed and high tem- perature foods and beverages [4–6]. From a public health perspective, risk factors with a high risk ratio but a low prevalence may be relatively less important in the popula- tion context. On the contrary, factors having a moderate risk ratio but with a high prevalence can be associated with a substantial fraction of the population disease burden. Therefore, it is of importance not only to identify specific risk factors and their risk ratios for a disease, but also to quantify the risk attributable to specific factors in the pop- ulation. The population attributable fraction (PAF) is a useful method to measure the burden of disease that can be attributed to particular exposures in a whole community, and provides an important link between etiology and 0304-3835/$ - see front matter Ó 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.canlet.2011.05.003 ⇑ Corresponding author. Address: No. 172 Jiangsu Road, Nanjing 210009, China. Tel./fax: +86 25 83759411. E-mail address: Jinkouzhao@hotmail.com (J.-K. Zhao). Cancer Letters 308 (2011) 189–196 Contents lists available at ScienceDirect Cancer Letters journal homepage: www.elsevier.com/locate/canlet