title: Contact with animals and risk of oesophageal squamous cell carcinoma: outcome of a case-control study from Kashmir, a high-risk region.
abstract: BACKGROUND
  Several studies have reported association between animal contact and some cancer types, including lymphohaematopoietic, colon, pancreatic and neurological malignancies. We aimed to investigate the association between animal contact and risk of oesophageal squamous cell carcinoma (ESCC) in a case-control study in Kashmir, India, area with a relatively high incidence of ESCC.
  
  
  METHODS
  We recruited 703 histologically confirmed ESCC cases and 1664 controls individually matched to the cases for age, sex and district of residence. Information, including on animal contact, was obtained in face-to-face interviews using a structured questionnaire. Conditional logistic regression models were used to calculate ORs and 95% CIs.
  
  
  RESULTS
  As compared with no contact with animals, daily close contact was associated with an increased risk of ESCC (OR 5.99; 95% CI 3.86 to 9.31) in models adjusted for several potential confounding factors, including multiple indicators of socioeconomic status. This association persisted in subgroups following stratification by a composite wealth score and occupation. Irregular contact with animals was not associated with ESCC risk. The association between duration of animal contact and ESCC risk was mixed; however, contact for more than 50 years was associated with an increased risk (OR 3.10; 95% CI 1.53 to 6.26). Frequency (p for trend, 0.001) and duration (p for trend, <0.001) of animal contact showed dose-response association with ESCC risk.
  
  
  CONCLUSIONS
  Our results suggest an association between long-term and daily close contact with animals and ESCC. This association needs to be investigated in further studies.
authors.affiliation: Department of Biochemistry, University of Kashmir, Hazratbal Srinagar, Jammu and Kashmir, India.
authors.forename: Nazir Ahmad
authors.initials: NA
authors.lastname: Dar
authors.forename: Farhad
authors.initials: F
authors.lastname: Islami
authors.forename: Gulzar Ahmad
authors.initials: GA
authors.lastname: Bhat
authors.forename: Idrees Ayoub
authors.initials: IA
authors.lastname: Shah
authors.forename: Muzamil Ashraf
authors.initials: MA
authors.lastname: Makhdoomi
authors.forename: Beenish
authors.initials: B
authors.lastname: Iqbal
authors.forename: Rumaisa
authors.initials: R
authors.lastname: Rafiq
authors.forename: Mohd Maqbool
authors.initials: MM
authors.lastname: Lone
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D000368:Aged; D000822:Animal Husbandry; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000209:etiology*; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004938:Esophageal Neoplasms / Q000209:etiology*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D007194:India; D007407:Interviews as Topic; D058751:Livestock; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects; D009790:Occupations; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D013997:Time Factors