Table 8

Pack-years of cigarette smoking and imputed NAT2 phenotype: multivariate-adjusteda ORs (95% CI) for various polyp pathology characteristics versus controls

Polyp characteristicsPack-yearsP-interaction
01–1920+Slopes (1 df)bNAT2 × smoking (2 df)b
Hyperplastic polyp
 Slow1.02.4 (1.4–4.2)3.5 (2.0–6.1)0.880.94
 Intermediate/fast1.2 (0.6–2.2)2.7 (1.5–4.9)3.6 (2.0–6.5)
Adenoma
 Slow1.01.4 (0.9–2.1)2.0 (1.3–2.9)0.980.94
 Intermediate/fast1.1 (0.7–1.6)1.5 (1.0–2.4)2.0 (1.3–3.0)
Multiple adenomas
 Slow1.01.3 (0.7–2.6)2.2 (1.2–4.0)0.950.55
 Intermediate/fast1.1 (0.6–2.3)2.5 (1.3–4.8)2.6 (1.4–5.0)
≥1 cm adenoma
 Slow1.02.3 (1.3–4.1)2.1 (1.2–3.8)0.840.42
 Intermediate/fast1.3 (0.7–2.4)1.6 (0.8–3.2)2.6 (1.4–4.7)
Tubulovillous adenoma
 Slow1.02.2 (1.2–3.9)2.2 (1.2–3.8)0.980.29
 Intermediate/fast1.2 (0.6–2.2)1.2 (0.6–2.4)2.0 (1.1–3.7)
  • a Adjusted for age, sex, nonsteroidal anti-inflammatory drug use, and hormone replacement therapy use.

  • b df, degree(s) of freedom.