Table 2

ORs for smoking variables according to NAT2 genotype in a population-based case-control study of breast cancer in Germany, 1992–1995

Rapid acetylatorsSlow acetylators
Cases (179)Controls (355)OR (95% CI)aCases (243)Controls (532)OR (95% CI)a
Ever-active smokingb
 No821371.0922311.0
 Yes972170.65 (0.44–0.97)1513011.24 (0.89–1.71)
 Missing1
Ever tobacco exposure
 Never active/passive14381.025751.0
 Passive only68962.02 (0.99–4.10)671561.19 (0.69–2.07)
 Ever-active smoker972171.12 (0.56–2.22)1513011.40 (0.84–2.34)
  Current active591181.22 (0.59–2.54)841471.67 (0.97–2.89)
  Ex-active38991.02 (0.49–2.13)671541.16 (0.67–2.03)
 Missing4
Pack-yearsc
 >0–10531280.99 (0.49–2.01)851941.24 (0.73–2.12)
 11+43881.24 (0.60–2.57)661061.79 (1.01–3.18)
 Missing151
Durationc
 1–9 years17401.07 (0.45–2.54)27850.88 (0.46–1.67)
 10–19 years34771.10 (0.51–2.36)48981.39 (0.77–2.51)
 20+ years461001.16 (0.55–2.44)761181.84 (1.05–3.24)
 Missing4
Time since cessationc,d
 ≥1–9 years18381.35 (0.57–3.20)26451.58 (0.78–3.19)
 10–19 years10400.62 (0.24–1.63)28681.15 (0.60–2.22)
 20+ years10211.28 (0.47–3.50)13410.71 (0.32–1.60)
  • a OR (95% CI): stratified for age by five year intervals, additionally adjusted for number of full-term pregnancies as a categorical variable (0, 1–2, 3 or more full-term pregnancies), total number of months of breastfeeding and body mass index as continuous variables, average daily alcohol intake (categorized as 0, 1–18, 19+ grams per day), first degree family history, education (classified into low, intermediate, and high, according to type of schooling attained and the subsequently obtained professional degree), and for menopausal status (postmenopausal, premenopausal, and unknown).

  • b Passive smokers were included in the reference group.

  • c Reference group was never-active/passive smoker, and a category of passive only smokers was included in all of the models.

  • d Current smokers were excluded from analysis.