title: A case-control study of tobacco use and other non-occupational risk factors for t(14;18) subtypes of non-Hodgkin's lymphoma (United States).
abstract: OBJECTIVE
  Non-Hodgkin's lymphoma (NHL) encompasses diverse subtypes, and analyzing NHL as a single outcome may mask associations. In a new approach we evaluated associations with subtypes defined by the t(14;18) translocation, reasoning that cases within these subtypes would have more common risk factors than all NHL combined.
  
  
  METHODS
  Archival biopsies from cases in a population-based NHL study were assayed for t(14;18) using polymerase chain reaction amplification. Exposures in 68 t(14;18)-positive and 114-negative cases were compared with 1245 controls. The expectation-maximization algorithm was used to fit polytomous regression models based on all available information, including data from 440 unclassified cases.
  
  
  RESULTS
  Family history of hemolymphatic cancer was associated with t(14;18)-negative NHL (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.4 3.9). but not t(14;18)-positive NHL. Cigarette smoking was weakly associated with t(14;18)-positive NHL (OR 1.7, CI 0.9-3.3), but ORs decreased as smoking increased. Chewing tobacco was associated with t(14;18)-positive NHL, particularly when used before age 18 (OR 2.5. CI 1.0-6.0, 13 exposed cases). Odds ratios for both case-subtypes were doubled among hair-dye users.
  
  
  CONCLUSIONS
  Cigarette smoking was not clearly associated with t(14;18)-positive NHL. Family history may be a marker for factors that act specifically through t(14;18)-negative pathogenic mechanisms.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Schroeder
authors.forename: A F
authors.initials: AF
authors.lastname: Olshan
authors.forename: R
authors.initials: R
authors.lastname: Baric
authors.forename: G A
authors.initials: GA
authors.lastname: Dent
authors.forename: C R
authors.initials: CR
authors.lastname: Weinberg
authors.forename: B
authors.initials: B
authors.lastname: Yount
authors.forename: J R
authors.initials: JR
authors.lastname: Cerhan
authors.forename: C F
authors.initials: CF
authors.lastname: Lynch
authors.forename: L M
authors.initials: LM
authors.lastname: Schuman
authors.forename: P E
authors.initials: PE
authors.lastname: Tolbert
authors.forename: N
authors.initials: N
authors.lastname: Rothman
authors.forename: K P
authors.initials: KP
authors.lastname: Cantor
authors.forename: A
authors.initials: A
authors.lastname: Blair
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005192:Family Health; D006801:Humans; D015994:Incidence; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014178:Translocation, Genetic