Which of the following risk factors is associated with both adenocarcinoma and squamous cell carcinoma of the esophagus? 

A. Barrett esophagus 

B. Chronic gastroesophageal reflux disease 

C. Cigarette smoking 

D. Lye ingestion 

E. Male sex

The answer is C. (Chap. 76) A variety of causative factors have been implicated in the development of squamous cell cancers of the esophagus. In the United States, the etiology of such cancers is primarily related to excess alcohol consumption and/or cigarette smoking. The relative risk increases with the amount of tobacco smoked or alcohol consumed, with these factors acting synergistically. Squamous cell esophageal carcinoma has also been associated with the ingestion of nitrates, smoked opiates, and fungal toxins in pickled vegetables, as well as mucosal damage caused by such physical insults as long-term exposure to extremely hot tea, the ingestion of lye, radiation-induced strictures, and chronic achalasia. The presence of an esophageal web in association with glossitis and iron deficiency (i.e., Plummer-Vinson or Paterson-Kelly syndrome) and congenital hyperkeratosis and pitting of the palms and soles (i.e., tylosis palmaris et plantaris) have each been linked with squamous cell esophageal cancer, as have dietary deficiencies of molybdenum, zinc, selenium, and vitamin A. Several strong etiologic associations have been observed to account for the development of adenocarcinoma of the esophagus. Such tumors arise in the distal esophagus in association with chronic gastric reflux, often in the presence of Barrett esophagus (replacement of the normal squamous epithelium of the distal esophagus by columnar mucosa), which occurs more commonly in obese individuals. Adenocarcinomas arise within dysplastic columnar epithelium in the distal esophagus. Cigarette smoking is associated with the development of adenocarcinoma of the esophagus as well.