title: Esophageal cancer in northwestern Iran.
abstract: BACKGROUND
  Esophageal cancer (EC) is one of the most frequent and serious cancers worldwide, but its geographic distribution is disparate. Northern Iran is known as one of the hot spots for EC, but there is inadequate evidence available regarding its characteristics in northwestern region of Iran. Therefore, this study aimed to describe some demographic and histopathologic features of EC in this region of Iran.
  
  
  METHODS
  166 hospital referral patients from a hospital in the northwestern region of Iran who underwent endoscopic biopsy for the chief complaint of dysphagia or odynophagia, and were admitted with the pathologic diagnosis of esophageal cancer during 3 years were enrolled in this study.
  
  
  RESULTS
  The mean age of the patient was 61.8 ± 12.0 years old. Male/female ratio was 0.84. With respect to the site of tumor, tumor was located in cervical esophagus in 7 cases (4.2%), upper thoracic in 5 patients (3%), middle thoracic in 64 patients (38.6%), lowers thoracic in 68 cases (41%), and cardia in 22 cases (13.2%). There was a significant difference among the site of tumor in different age groups (P = 0.021) and different sex groups (P = 0.001). In men, EC usually involves the lower parts, whereas in women it usually involves the upper parts of esophagus. Squamous cell carcinoma was the most common type of EC in all age groups, but the prevalence rate of adenocarcinoma seems to increase with age (P = 0.045).
  
  
  CONCLUSIONS
  Demographic and histopathologic pattern of esophageal cancer in northwestern region of Iran is different from its histopathologic pattern in western countries in accordance with other reports from Golestan province in north-eastern region of Iran.
authors.affiliation: National Institute of Health Research, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Pedram
authors.forename: R
authors.initials: R
authors.lastname: Mahmodlou
authors.forename: A
authors.initials: A
authors.lastname: Enshayi
authors.forename: N
authors.initials: N
authors.lastname: Sepehrvand
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D003430:Cross-Sectional Studies; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015996:Survival Rate; D016896:Treatment Outcome