Geographical variation in the epidemiology of esophageal cancer in Pakistan.

ABSTRACT

STUDY OBJECTIVES: To evaluate whether factors such as the geographic area of residence, sex, and anatomic subsite of esophagus can prognosticate the histologic subtype of esophagus cancer. DESIGN: To study the major histologic subtypes of esophagus cancer stratified by various factors through multivariate analyses using morphology as the dependent factor and gender, province, and subsite of esophagus as independent factors. SETTING: A tertiary care cancer hospital situated in the city of Lahore in Pakistan. PATIENTS Three hundred and thirty five patients diagnosed either with esophageal squamous cell carcinoma or adenocarcinoma, from December 1994 to April 2004, were included. Subjects were residents of either Punjab or the Northwest Frontier Province in Pakistan. MAIN RESULTS: An excessive likelihood of development of squamous cell carcinoma versus adenocarcinoma was established for the Northwest Frontier Province as compared to Punjab (odds ratio 2.7, 95 percent confidence interval 1.2, 6.2, p = 0.02), and in the upper-third of the esophagus relative to the lower-third of the organ (odds ratio 8.8, 95 percent confidence interval 2.8, 28.3, p < 0.001). CONCLUSIONS: This histologic variation may be explained by environmental and lifestyle factors peculiar to geographical regions.