title: Maternal smoking during pregnancy and childhood lymphoma: a meta-analysis.
abstract: Results from epidemiological studies exploring the association between childhood lymphoma and maternal smoking during pregnancy have been contradictory. This meta-analysis included all published cohort (n = 2) and case-control (n = 10) articles; among the latter, the data of the Greek Nationwide Registry for Childhood Hematological Malignancies study were updated to include all recently available cases (-2008). Odds ratios (ORs), relative risks and hazard ratios were appropriately pooled in three separate analyses concerning non-Hodgkin lymphoma (NHL, n = 1,072 cases), Hodgkin lymphoma (HL, n = 538 cases) and any lymphoma (n = 1,591 cases), according to data availability in the included studies. An additional metaregression analysis was conducted to explore dose-response relationships. A statistically significant association between maternal smoking (any vs. no) during pregnancy and risk for childhood NHL was observed (OR = 1.22, 95% confidence interval, CI: 1.03-1.45, fixed effects model), whereas the risk for childhood HL was not statistically significant (OR = 0.90, 95% CI: 0.66-1.21, fixed effects model). The analysis on any lymphoma did not reach statistical significance (OR = 1.10, 95% CI = 0.96-1.27, fixed effects model), possibly because of the case-mix of NHL to HL. No dose-response association was revealed in the metaregression analysis. In conclusion, this meta-analysis points to a modest increase in the risk for childhood NHL, but not HL, among children born by mothers smoking during pregnancy. Further investigation of dose-response phenomena in the NHL association, however, warrants accumulation of additional data.
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Athens University Medical School, Athens, Greece.
authors.forename: C N
authors.initials: CN
authors.lastname: Antonopoulos
authors.forename: T N
authors.initials: TN
authors.lastname: Sergentanis
authors.forename: C
authors.initials: C
authors.lastname: Papadopoulou
authors.forename: E
authors.initials: E
authors.lastname: Andrie
authors.forename: N
authors.initials: N
authors.lastname: Dessypris
authors.forename: P
authors.initials: P
authors.lastname: Panagopoulou
authors.forename: S
authors.initials: S
authors.lastname: Polychronopoulou
authors.forename: A
authors.initials: A
authors.lastname: Pourtsidis
authors.forename: F
authors.initials: F
authors.lastname: Athanasiadou-Piperopoulou
authors.forename: M
authors.initials: M
authors.lastname: Kalmanti
authors.forename: V
authors.initials: V
authors.lastname: Sidi
authors.forename: M
authors.initials: M
authors.lastname: Moschovi
authors.forename: E T
authors.initials: ET
authors.lastname: Petridou
mesh_terms: D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000209:etiology*; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000209:etiology*; D009035:Mothers; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000209:etiology*; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D015996:Survival Rate