Esophageal Cancer in Iran: A Review

Esophageal cancer is the second and third most common malignancy in Iranian malesand females, respectively, claiming lives of approximately 5800 Iranians each year.Squamous cell carcinoma (SCC) is presently the most common type accounting forabout 90% of all esophageal cancers in Iran. Recent studies have shown that there isa gradual increase in the incidence of adenocarcinoma of the distal esophagus alongwith gastric cardia adenocarcinoma. Thirty-five years ago, the age standardizied rate (ASR) of esophageal SCC in thecity of Gonbad (Golestan Province, northeast of Iran) was found to be one of the highestrates for any single cancer that had been reported worldwide (ASR >100/105/year).Recent studies have shown that the incidence of SCC in Gonbad has declined to lessthan half of what it was in the past. This decline in the incidence of esophageal SCCparallels an improvement in the socioeconomic situation of people living in thisregion. According to recent cancer registry data in Iran there is still an obviousintracountry variability between the incidence of esophageal cancer in the south withan ASR of 3 for males and 2 for females in Kerman and 43 and 36 in the northeasternprovince of Golestan. The reasons for this very high rate of SCC in northeastern Iranhave been the subject of several studies during the past 35 years. According to resultsof these studies the suspected risk factors are: low intake of fruits and vegetables, drinkinghot tea, consumption of opium products and tobacco, H.pyloriinfection in the stomach,using unhealthy drinking water from cisterns and genetic susceptibility. The mainsuspected mutagens are polycyclic aromatic hydrocarbons (PAH) and N-nitrosocompounds. In order to embark primary and secondary prevention of this fatal cancer,further prospective studies are presently underway in the region. The Golestanesophageal cancer cohort study which follows of 50,000 subjects is on going. We expectsimple and feasible evidence based preventive strategies to be implemented in the futureaccording to the results of this study.