Cancer of the gastrointestinal tract. Etiological and environmental factors

Abstract

Epidemiologic surveys of cancer of the esophagus have revealed that two principal risk factors predominate in its cause: smoking and high alcohol consumption. The risk of developing cancer of the esophagus is significantly higher among smokers, whether cigarettes, cigars, or pipes are involved (Fig 1). These findings have been documented fully by prospective studies which report that the risk for smokers is anything from two to six times that of nonsmokers (Table 2).^7-11 In several retrospective studies, it has been noted that heavy alcohol consumption significantly increases the risk of smokers to develop esophageal cancer (Fig 2).^12-14The effect appears to result from the total amount of alcohol consumed rather than the type of alcohol or whether it was drunk straight or diluted. Persons (particularly women) with Plummer-Vinson disease, a condition caused by nutritional deficiency, have an increased risk to develop esophageal cancer.²In areas where this