title: Multiple pathway-based genetic variations associated with tobacco related multiple primary neoplasms.
abstract: BACKGROUND
  In order to elucidate a combination of genetic alterations that drive tobacco carcinogenesis we have explored a unique model system and analytical method for an unbiased qualitative and quantitative assessment of gene-gene and gene-environment interactions. The objective of this case control study was to assess genetic predisposition in a biologically enriched clinical model system of tobacco related cancers (TRC), occurring as Multiple Primary Neoplasms (MPN).
  
  
  METHODS
  Genotyping of 21 candidate Single Nucleotide Polymorphisms (SNP) from major metabolic pathways was performed in a cohort of 151 MPN cases and 210 cancer-free controls. Statistical analysis using logistic regression and Multifactor Dimensionality Reduction (MDR) analysis was performed for studying higher order interactions among various SNPs and tobacco habit.
  
  
  RESULTS
  Increased risk association was observed for patients with at least one TRC in the upper aero digestive tract (UADT) for variations in SULT1A1 Arg²¹³His, mEH Tyr¹¹³His, hOGG1 Ser³²⁶Cys, XRCC1 Arg²⁸⁰His and BRCA2 Asn³⁷²His. Gene-environment interactions were assessed using MDR analysis. The overall best model by MDR was tobacco habit/p53(Arg/Arg)/XRCC1(Arg³⁹⁹His)/mEH(Tyr¹¹³His) that had highest Cross Validation Consistency (8.3) and test accuracy (0.69). This model also showed significant association using logistic regression analysis.
  
  
  CONCLUSIONS
  This is the first Indian study on a multipathway based approach to study genetic susceptibility to cancer in tobacco associated MPN. This approach could assist in planning additional studies for comprehensive understanding of tobacco carcinogenesis.
authors.affiliation: Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Kotnis
authors.forename: Junghyun
authors.initials: J
authors.lastname: Namkung
authors.forename: Sadhana
authors.initials: S
authors.lastname: Kannan
authors.forename: Nallala
authors.initials: N
authors.lastname: Jayakrupakar
authors.forename: Taesung
authors.initials: T
authors.lastname: Park
authors.forename: Rajiv
authors.initials: R
authors.lastname: Sarin
authors.forename: Rita
authors.initials: R
authors.lastname: Mulherkar
mesh_terms: D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D003710:Demography; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D058011:Multifactor Dimensionality Reduction; D009378:Neoplasms, Multiple Primary / Q000235:genetics*; D019683:Penetrance; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics*; D062789:Tobacco Products