The esophagus is a part of the upper digestive tract, connecting the oral pharynx above and the stomach below, located in the middle of the chest behind the sternum, serving as a soft tube for food transportation. The inner wall of the esophagus is lined with mucous membrane, and malignant tumors that occur on the esophageal mucosa are called esophageal cancer, which is one of the common malignant tumors. The onset of esophageal cancer is slow and often goes unnoticed. In some areas, the incidence of esophageal cancer is particularly high among elderly residents.
The incidence rate of esophageal cancer varies greatly in different countries and regions within a country, with differences of over 100-200 times. It is more prevalent in developing countries and among populations with poorer economic conditions. Approximately 90% of esophageal cancer cases worldwide occur in developing countries in Asia, Africa, and Latin America. In 1996, there were approximately 480,000 new cases worldwide, accounting for 4.6% of all new cases of malignant tumors and ranking as the eighth most common cancer globally. According to data from the International Association of Cancer Registries, the incidence rate is higher among residents in certain regions of Asia, Africa, and Latin America, including black populations, Chinese (Singapore, Hong Kong), Indians (Mumbai, Pune), Japanese (Kanzaki), Puerto Rico, Brazil, and Lee. The incidence rate is higher among males in these regions. Esophageal cancer is also common in certain areas of France and in communities of African Americans in the United States. The Black Sea region in Iran and South Africa have high incidence rates of esophageal cancer, and some areas in the Caribbean are considered high-risk areas. Europe, North America, and Oceania have lower incidence rates, with Romania having the lowest rate.
The Taihang Mountain area, located at the junction of the provinces of Shanxi, Henan, and Hebei in China, is a high-incidence area of esophageal cancer. In China, esophageal cancer is mainly concentrated in the North China Taihang Mountain region, Sichuan Basin, northwest Sichuan, as well as parts of Fujian, Guangdong, Hubei, Shandong, Jiangsu, Shaanxi, Anhui, Gansu, and Xinjiang provinces. The incidence rate is higher in rural and mountainous areas than in cities. The mortality rate in counties and cities with high levels ranges from 100/100,000 to 150/100,000 or more; in counties and cities with low levels, the mortality rate is below 1/100,000.
In 1997, the Office of Cancer Prevention and Control of the Ministry of Health in China reported that the age-adjusted mortality rate for esophageal cancer in China was 15.02/100,000 population, accounting for 16.05% of all cancer deaths. It ranked fourth among urban malignant tumor deaths and third among rural deaths. Compared with the early 1990s and mid-1970s, the mortality rate of esophageal cancer in China showed a slight downward trend. In particular, the mortality rate of esophageal cancer in some urban areas has decreased by 42% for males and 49% for females. The survey showed that esophageal cancer is essentially a disease of the elderly. Approximately 75% of all esophageal cancer deaths occurred between the ages of 50 and 70. Cases before the age of 30 are rare, and male patients outnumber female patients.
Province-wise, the highest mortality rate for esophageal cancer was in Shanxi Province (64/100,000 male population, 36/100,000 female population), and the lowest was in Yunnan Province (2.43/100,000 male population, 0.89/100,000 female population). Linzhou City (formerly known as Lin County) in Henan Province, China, is one of the highest incidence areas of esophageal cancer in the world. In 1980, the world-adjusted incidence rate of esophageal cancer for males in Lin County, China, was 161/100,000 population, and for females, it was 103/100,000 population.