Research ArticlesCytokeratin Immunoexpression in Esophageal Squamous Cell Carcinoma of High-risk Population in Northeast IndiaSingh, Avninder MD*; Kapur, Sujala MD*; Chattopadhyay, Indranil MSc*; Purkayastha, Joydeep MS†; Sharma, Jagannath MD†; Mishra, Ashwani PhD*; Hewitt, Stephen M. MD, PhD‡; Saxena, Sunita MD*Author Information *Institute of Pathology, Indian Council of Medical Research, New Delhi †B. Borooah Cancer Institute, Guwahati, Assam, India ‡Tissue Array Research Laboratory, National Cancer Institute, National Institutes of Health, Bethesda Source of support: Financial support to Avninder Singh for the ICRETT technology transfer fellowship UICC (International Union against Cancer). This research was supported in part by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research. Reprints: Stephen M. Hewitt, MD, PhD, Tissue Array Research Laboratory, National Cancer Institute, National Institutes of Health, Bethesda 20892-4605 (e-mail: firstname.lastname@example.org). Received for publication October 29, 2008; accepted January 19, 2009 Applied Immunohistochemistry & Molecular Morphology: October 2009 - Volume 17 - Issue 5 - p 419-424 doi: 10.1097/PAI.0b013e31819d3753 Buy Metrics Abstract Esophageal cancer is a frequently fatal malignancy, and is described in certain regions in Northeast India with an incidence of esophageal squamous cell carcinoma many fold higher than the rest of the population. The population in Northeast India is at higher risk due to poor nutritional status, consumption of fermented betel quid and other oral tobacco products besides smoking and alcohol intake. Cytokeratins (CKs) are the major constituents of the esophageal epithelium and may show gain or loss of CKs as the cancer progresses from normal epithelium to invasive phenotype. In this study, we studied the immunohistochemical expression of 5 CKs (CK4, CK5, CK8, CK14, and CK17) in the normal esophageal epithelium and esophageal squamous cell carcinoma from both the general population and the high-risk population of Assam in Northeast India. The CK expression profile was similar to other published data in general. Further analysis demonstrated differences in CK expression between the general and the high-risk tumor samples. CK5 and CK8 expression was altered in the high-risk population. The significance of these differences is unclear, but suggests a connection to the etiologic factors. © 2009 Lippincott Williams & Wilkins, Inc.