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 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Number | HL overall | EBV-positive lymphoma | EBV-negative lymphoma | |||||||
| Number | OR (95% CI) | OR (95% CI) | OR (95% CI) | |||||||
| Never smokers | 1,460 | 299 | Reference | Reference | Reference | |||||
| Ever smokers | 1,665 | 275 | 1.18 (0.94-1.48) | 1.62 (1.08-2.43) | 1.13 (0.86-1.49) | |||||
| Phomogeneity* | 0.15 | 0.01 | 0.39 | |||||||
| Former smokers | 949 | 92 | 0.80 (0.59-1.08) | 0.95 (0.55-1.65) | 0.80 (0.55-1.17) | |||||
| Current smokers | 712 | 182 | 1.57 (1.22-2.03) | 2.36 (1.51-3.71) | 1.43 (1.05-1.97) | |||||
| Phomogeneity† | <0.0001 | <0.001 | 0.01 | |||||||
| Age at initiation (y)‡ | ||||||||||
| ≤14 | 164 | 57 | 1.84 (1.22-2.77) | 2.25 (1.10-4.61) | 2.06 (1.25-3.41) | |||||
| 15-19 | 362 | 91 | 1.43 (1.04-1.98) | 1.86 (1.04-3.35) | 1.32 (0.89-1.96) | |||||
| ≥20 | 177 | 33 | 1.61 (1.02-2.56) | 3.83 (1.95-7.53) | 1.05 (0.55-1.97) | |||||
| Ptrend | 0.68 | 0.27 | 0.14 | |||||||
| Intensity (cigarettes/day)‡ | ||||||||||
| 1-9 | 141 | 31 | 1.12 (0.69-1.83) | 1.42 (0.59-3.41) | 1.08 (0.60-1.94) | |||||
| 10-19 | 357 | 103 | 1.85 (1.35-2.54) | 3.10 (1.81-5.29) | 1.59 (1.07-2.35) | |||||
| ≥20 | 201 | 46 | 1.49 (0.97-2.57) | 2.16 (1.06-4.42) | 1.43 (0.84-2.42) | |||||
| Ptrend | 0.58 | 0.93 | 0.58 | |||||||
| Duration (y)‡ | ||||||||||
| ≤9 | 31 | 34 | 1.61 (0.89-2.91) | 2.39 (0.95-6.04) | 1.38 (0.70-2.71) | |||||
| 10-29 | 144 | 82 | 1.41 (0.98-2.05) | 1.77 (0.91-3.44) | 1.26 (0.81-1.95) | |||||
| ≥30 | 528 | 65 | 1.72 (1.20-2.46) | 3.14 (1.66-5.93) | 1.68 (1.04-2.70) | |||||
| Ptrend | 0.81 | 0.53 | 0.64 | |||||||
| Cumulative exposure (cigarette years)‡ | ||||||||||
| ≤149 | 69 | 53 | 1.63 (1.03-2.57) | 1.68 (0.75-3.75) | 1.51 (0.89-2.54) | |||||
| 150-299 | 118 | 42 | 1.33 (0.84-2.11) | 1.83 (0.79-4.23) | 1.14 (0.65-1.99) | |||||
| ≥300 | 511 | 85 | 1.66 (1.20-2.31) | 3.14 (1.81-5.46) | 1.53 (1.00-2.34) | |||||
| Ptrend | 0.36 | 0.65 | 0.87 | |||||||
| Time since cessation (y)§ | ||||||||||
| 1-4 | 126 | 15 | 0.72 (0.37-1.37) | 0.75 (0.22-2.57) | 0.40 (0.15-1.06) | |||||
| 5-9 | 136 | 24 | 0.86 (0.49-1.51) | 1.42 (0.56-3.57) | 0.90 (0.45-1.77) | |||||
| ≥10 | 687 | 54 | 0.86 (0.56-1.15) | 0.87 (0.45-1.69) | 0.91 (0.58-1.42) | |||||
| Ptrend | 0.66 | 0.64 | 0.60 | |||||||
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.