Research on esophageal cancer: With personal perspectives from studies in China and Kenya

Abstract

The most common form of esophageal cancer (EC), esophageal squamous cell carcinoma (ESCC), is prevalent in many unindustrialized societies, among people with lower socioeconomic status and those who frequently use tobacco and alcohol. In some areas, ESCC mortality ranked top among all cancer. In this review, we begin with discussions of the extensive research on EC in Linxian in northern China that started 60 years ago and the recent studies in Kenya from our personal perspectives. Based on the results obtained from these studies and information from the literature, we summarize our current understanding about the risk factors for ESCC including lifestyle factors (smoking, alcohol, consumption of food and beverages at high temperature and other unhealthy habits), poor diet and nutritional insufficiencies and genetic susceptibility. Elimination or minimization of these environmental risk factors, as well as early detection and treatment of precancerous lesions, would be effective means for the prevention of ESCC. Current knowledge of molecular alterations in ESCC (gene mutations, hypermethylation and amplification or overexpression), as well as treatment of ESCC and the potential of targeted therapy, are also discussed. Finally, we propose effective approaches for the prevention of ESCC by adapting a healthy lifestyle, including a healthy diet that would also prevent other diseases. Community outreach, public education and international collaboration are important for achieving this public health goal.

Keywords: esophageal cancer; molecular alterations; prevention; risk factors; therapy.

FIGURE 1

Professor Qiong Shen and balloon cytology. A, A photo of Professor Qiong Shen; B, balloons used in the 1970s for balloon cytology. C, Professor Shen performing balloon cytology on Dr Sanford Dawsey of the National Cancer Institute (NCI). D,E, Newer versions of the balloons used for cytology and a quotation from Dr Shen. (thank to Dr Dawsey for providing these photos)

FIGURE 2

Photos of the Linxian Nutritional Intervention Trials. A, Site visit of National Cancer Institute (NCI) and other investigators to Linxian before launching the intervention. B,C, Interviewing and physical examination at the beginning of the trial. (Photos taken by Chung S. Yang.) D, Chung S. Yang (in striped shirt) observing pill counting for compliance analysis