[Epidemiology and risk factors of the esophageal squamous cell carcinoma].

Esophageal carcinoma is the eighth most common malignancy in the world. In most countries, including Poland, the squamous cell carcinoma is a predominant histological type. It is characterized by extreme diversity in geographical distribution and incidence. High incidence is noted in regions located along with so-called "Asian esophageal cancer belt" beginning from eastern Turkey through Caspian littoral countries, northern Afghanistan to Central and Eastern Asia, as well as in Japan, South Africa and some South American countries. In Western Europe the highest incidence is observed in France, Portugal and northern Italy. Poland belongs to low-incidence countries with the age-standardized annual incidence exceeding 4.5 and 0.7/100,000, for men and women respectively. Etiology of the cancer is multi-factorial. In western countries the most important risk factors are tobacco smoking and alcohol consumption, and to a lesser extent, an inappropriate diet. In other countries, a diet lacking of fresh vegetables and fruits with vitamin and mineral deficiency and high level of sodium chloride, carbohydrates and animal fats is a predominant factor. Furthermore, preserving and processing food which facilitates accumulation of carcinogens, special dietary habits and viral infections are also attributed to the development of cancer. More recently, the significance of genetically determined increased susceptibility of some individuals versus environmental factors has been stressed. Previous studies proved the relationship between cancer susceptibility and polymorphisms in genes encoding some important molecules engaged in carcinogens metabolism or DNA repair.