In those high-incidence regions that provide information on histological type, approximately 90 % are squamous cell carcinomas (Fig. 1.2). This is in contrast to some lower-risk populations, such as Caucasian Americans and Europeans, where adenocarcinomas are predominant. For example, in the USA, SEER (non-Hispanic White) indicated ASR 5.3 in men where 67 % of cases are coded as adenocarcinoma as opposed to 25 % squamous cell carcinoma. In contrast, Japan, Nagasaki indicated ASR 9.1 in men where only 2 % of cases are coded as adenocarcinoma as opposed to 93 % squamous cell carcinoma.

In 2011, 10,141 men and 1,829 women died from esophageal cancer, representing 4.8 and 1.3 % of the total cancer death in men and women, respectively. Mortality rates increased with age rapidly after 40 years (Fig. 1.3). The mortality rate of esophageal cancer is estimated to be 0.67 % in men and 0.09 % in women up to 75 years, increasing to 1.17 % in men and 0.20 % in women over lifetime. Regarding incidence, 17,004 men and 2.990 women were estimated to be diagnosed with esophageal cancer in 2007 and the probability of esophageal cancer diagnosis was 1.35 % in men and 0.19 % in women up to 75 years, increasing to 2.16 % in men and 0.43 % in women for lifetime. Five-year survival rates were 32.3 % in men and 41.3 % in women who were diagnosed with esophageal cancer in 2003–2005 based on the population-based cancer registry.

Both incidence and mortality rates are observed to have increased in number since 1960 due to the aging of Japanese population, while age-standardized rates are observed to have been consistently decreasing with the exception of the increasing male incidence rate (Fig. 1.4). Histological distribution trends were analyzed using eight population-based cancer registries with high level of reliability from 1993 to 2001 (Table 1.1) [3]. Squamous cell carcinoma remains the predominant type of esophageal cancer in Japan, and a remarkable increase in adenocarcinoma has not been observed before 2001. Disparity in the classification of esophageal and gastric cardia adenocarcinoma may have led to underestimation of esophageal adenocarcinoma incidence.

An increased trend of adenocarcinoma of the esophagogastric junction was observed among patients who had underwent surgery for advanced gastric adenocarcinoma in the National Cancer Center Hospital in Tokyo, from 2.3 % in 1962–1965 to 10.0 % in 2001–2005; however the proportion of Siewert type I (defined as adenocarcinoma of the distal esophagus) had remained very rare (approximately 1 % among adenocarcinoma of the esophagogastric junction) [4]. Since this finding was confined to operative cases with advanced gastric adenocarcinoma, the proportion of Siewert’s type I tumors may have been underestimated.

Established risk and protective factors for esophageal cancer are listed according to the level of certainty (Table 1.2). Tobacco smoking and alcohol consumption are convincing risk factors for esophageal cancer, especially squamous cell carcinoma. Mate, a traditional herbal beverage consumed in parts of South America, has been identified as a probable cause of esophageal cancer. Non-starchy vegetables, fruits, and foods containing beta-carotene and/or vitamin C probably prevent esophageal cancer.