Table 2.

Multivariate ORs with 95% CIs for the association between cigarette smoking and risk of classic HL overall and by tumor EBV status in a comparison with population controls

Controls
Classic HL
NumberHL overall
EBV-positive lymphoma
EBV-negative lymphoma
NumberOR (95% CI)OR (95% CI)OR (95% CI)
Never smokers1,460299ReferenceReferenceReference
Ever smokers1,6652751.18 (0.94-1.48)1.62 (1.08-2.43)1.13 (0.86-1.49)
Phomogeneity*0.150.010.39
    Former smokers949920.80 (0.59-1.08)0.95 (0.55-1.65)0.80 (0.55-1.17)
    Current smokers7121821.57 (1.22-2.03)2.36 (1.51-3.71)1.43 (1.05-1.97)
    Phomogeneity<0.0001<0.0010.01
Age at initiation (y)
    ≤14164571.84 (1.22-2.77)2.25 (1.10-4.61)2.06 (1.25-3.41)
    15-19362911.43 (1.04-1.98)1.86 (1.04-3.35)1.32 (0.89-1.96)
    ≥20177331.61 (1.02-2.56)3.83 (1.95-7.53)1.05 (0.55-1.97)
    Ptrend0.680.270.14
Intensity (cigarettes/day)
    1-9141311.12 (0.69-1.83)1.42 (0.59-3.41)1.08 (0.60-1.94)
    10-193571031.85 (1.35-2.54)3.10 (1.81-5.29)1.59 (1.07-2.35)
    ≥20201461.49 (0.97-2.57)2.16 (1.06-4.42)1.43 (0.84-2.42)
    Ptrend0.580.930.58
Duration (y)
    ≤931341.61 (0.89-2.91)2.39 (0.95-6.04)1.38 (0.70-2.71)
    10-29144821.41 (0.98-2.05)1.77 (0.91-3.44)1.26 (0.81-1.95)
    ≥30528651.72 (1.20-2.46)3.14 (1.66-5.93)1.68 (1.04-2.70)
    Ptrend0.810.530.64
Cumulative exposure (cigarette years)
    ≤14969531.63 (1.03-2.57)1.68 (0.75-3.75)1.51 (0.89-2.54)
    150-299118421.33 (0.84-2.11)1.83 (0.79-4.23)1.14 (0.65-1.99)
    ≥300511851.66 (1.20-2.31)3.14 (1.81-5.46)1.53 (1.00-2.34)
    Ptrend0.360.650.87
Time since cessation (y)§
    1-4126150.72 (0.37-1.37)0.75 (0.22-2.57)0.40 (0.15-1.06)
    5-9136240.86 (0.49-1.51)1.42 (0.56-3.57)0.90 (0.45-1.77)
    ≥10687540.86 (0.56-1.15)0.87 (0.45-1.69)0.91 (0.58-1.42)
    Ptrend0.660.640.60
  • NOTE: All analyses are adjusted for matching variables [age (in 10-y categories), sex, and country], number of younger and older siblings, history of infectious mononucleosis, mother's age at subject's birth, country-specific measure of mother's education, subject's education, and familial history of hematopoietic cancer.

  • * Test for homogeneity of effect of smoking history (ever versus never).

  • Test for homogeneity of effect of smoking status (former, current, never).

  • Among current smokers only.

  • § Among former smokers only.