title: Do the smoking intensity and duration, the years since quitting, the methodological quality and the year of publication of the studies affect the results of the meta-analysis on cigarette smoking and Acute Myeloid Leukemia (AML) in adults?
abstract: BACKGROUND
  The aim was to perform a systematic review and meta-analysis on the relationship between tobacco smoking and the onset of acute myeloid leukemia (AML) in adults.
  
  
  METHODS
  PubMed and Scopus databases were systematically searched. In the meta-analysis, random or fixed effects models were used according to the presence of heterogeneity. Study quality was assessed using the Newcastle-Ottawa Scale.
  
  
  RESULTS
  Twenty-seven articles were included. Case-control and cohort meta-analyses show that current, ever and former smokers have a significant increased risk to develop AML compared to never smokers [current: OR=1.36 (1.11-1.66) and RR=1.52 (1.10-2.14); ever: OR=1.25 (1.14-1.38) and RR=1.45 (1.10-1.90); former: OR=1.21 (1.03-1.41) and RR=1.45 (1.08-1.94)]. Moreover, increasing smoking intensity and duration is associated with an increase of the risk, OR shift from 1.14 (1-20 pack/years) to 2.36 (>40 pack/years).
  
  
  CONCLUSIONS
  Smoking may have a significant role in AML onset in a multistep pathogenesis.
authors.affiliation: Department of Public Health and Infectious Diseases, "Sapienza"-University of Rome, Italy.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Colamesta
authors.affiliation: Department of Public Health and Infectious Diseases, "Sapienza"-University of Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: D'Aguanno
authors.affiliation: Department of Cellular Biotechnologies and Hematology, "Sapienza"-University of Rome, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Breccia
authors.affiliation: Department of Public Health and Infectious Diseases, "Sapienza"-University of Rome, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Bruffa
authors.affiliation: Department of Cellular Biotechnologies and Hematology, "Sapienza"-University of Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Cartoni
authors.affiliation: Department of Public Health and Infectious Diseases, "Sapienza"-University of Rome, Italy. Electronic address: giuseppe.latorre@uniroma1.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Torre
mesh_terms: D000328:Adult; D015331:Cohort Studies; D016208:Databases, Factual; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000209:etiology*; D010506:Periodicals as Topic; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000639:trends*
keywords: Acute myeloid leukemia; Cigarette; Smoking; Tobacco