title: Expression of Epstein-Barr virus among oral potentially malignant disorders and oral squamous cell carcinomas in the South Indian tobacco-chewing population.
abstract: BACKGROUND
  Oral cancer is the sixth most common malignancy in the world. Viruses are the causative agents of approximately 10-15% of all cancers worldwide (Cancers, 6, 2014 and 2155). The tumorigenic roles of Epstein-Barr virus in oral cancer are unclear. Literature search results are conflicting and dependent on various factors such as geographical/regional variations, sociocultural lifestyles, dietary habits, chewing/smoking tobacco habit. This study is the first original observation about frequency of Epstein-Barr virus among South Indian tobacco-chewing patients to elucidate its involvement in oral carcinogenesis and to know whether this can be a valuable diagnostic and prognostic indicator.
  
  
  METHODS
  A total number of 75 tobacco chewer subjects aged between 23 and 76 years with histopathologically confirmed oral potentially malignant disorders (25), oral squamous cell carcinoma (25), and age-matched healthy controls (25) formed the study group. Immunohistochemical expression of Epstein-Barr virus latent membrane protein 1 was assessed among cases and healthy controls.
  
  
  RESULTS
  Out of the total 75 subjects, six subjects (8%) were positive for Epstein-Barr virus antigen and 69 subjects (92%) negative. The antigen positivity was observed among two cases of moderately differentiated oral squamous cell carcinoma, two cases of leukoplakia, and two healthy controls.
  
  
  CONCLUSIONS
  No significant association between Epstein-Barr virus positivity was observed among oral potentially malignant disorders and oral squamous cell carcinoma among South Indian tobacco-chewing patients. This can be partially explained by the methodology employed, by the patient population analyzed and different habits in various geographical regions.
authors.affiliation: Department of Oral Medicine & Radiology, M. S. Ramaiah Dental College & Hospital, Bangalore, Karnataka, India.
authors.forename: Sujatha S
authors.initials: SS
authors.lastname: Reddy
authors.affiliation: Department of Oral Medicine & Radiology, M. S. Ramaiah Dental College & Hospital, Bangalore, Karnataka, India.
authors.forename: Shivani
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Pathology, M. S. Ramaiah Medical College & Hospital, Bangalore, Karnataka, India.
authors.forename: Vijaya
authors.initials: V
authors.lastname: Mysorekar
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000821:virology*; D005260:Female; D004854:Herpesvirus 4, Human / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology / Q000821:virology*; D011379:Prognosis; D012307:Risk Factors; D014030:Tobacco, Smokeless / Q000009:adverse effects*
keywords: Epstein-Barr virus; immunohistochemistry; oral potentially malignant disorders; oral squamous cell carcinoma