title: Associations of lifestyle and diet with the risk of nasopharyngeal carcinoma in Singapore: a case-control study.
abstract: BACKGROUND
  Nasopharyngeal carcinoma (NPC) is a commonly diagnosed cancer in Southeast Asia. Many studies have examined the risk factors for NPC, yet the roles of some risk factors remain inconclusive. The purpose of this study was to examine associations between modifiable lifestyle factors and the risk of NPC in the Singaporean population.
  
  
  METHODS
  We conducted a case-control study in Singapore with 300 patients and 310 controls who were recruited between 2008 and 2012. Each control was selected and individually matched to each patient based on sex, ethnicity, and age (±5 years). A total of 290 pairs of cases and controls were matched successfully. We examined lifestyle factors such as tobacco smoking, alcohol drinking, various salted and preserved food consumption, and weaning practices.
  
  
  RESULTS
  After adjusting for covariates, multivariate analysis showed that those participants who were current smokers and had ever smoked tobacco had a higher risk of NPC than participants who had never smoked, with odds ratios (ORs) of 4.50 (95% confidence interval [CI] 2.58-7.86; P < 0.001) and 2.52 (95% CI 1.54-4.12; P < 0.001), respectively. Those who consumed salted vegetables at least once a week also showed a significantly increased risk of NPC than those who never or rarely consumed salted vegetables, with an OR of 4.18 (95% CI 1.69-10.38; P = 0.002).
  
  
  CONCLUSIONS
  Smoking (currently and ever-smoked) and consuming salted vegetables once a week or more were lifestyle risk factors for NPC, and changes of these factors for the better may reduce the risk of NPC.
authors.affiliation: Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore. graceyongncc@gmail.com.
authors.forename: Sook Kwin
authors.initials: SK
authors.lastname: Yong
authors.affiliation: Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore.|Medical Education, Research & Evaluation Department (MERE), Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
authors.forename: Tam Cam
authors.initials: TC
authors.lastname: Ha
authors.affiliation: Division of Radiation Oncology, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore.
authors.forename: Ming Chert Richard
authors.initials: MC
authors.lastname: Yeo
authors.affiliation: Genetic Cancer Susceptibility Group, International Agency for Research on Cancer, World Health Organization, 150 Cours Albert Thomas, 69372, Lyon Cedex 08, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Gaborieau
authors.affiliation: Genetic Cancer Susceptibility Group, International Agency for Research on Cancer, World Health Organization, 150 Cours Albert Thomas, 69372, Lyon Cedex 08, France.
authors.forename: James D
authors.initials: JD
authors.lastname: McKay
authors.affiliation: Division of Radiation Oncology, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wee
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology; D002277:Carcinoma / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D016017:Odds Ratio; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*
chemical_list: D017673:Sodium Chloride, Dietary
keywords: Alcohol drinking; Case–control study; Diet; Nasopharyngeal carcinoma; Preserved food; Smoking