Table 3

Risk of lung cancer related to CYP2A13 genotypes by smoking status and pack-years smoked

Smoking status	CC genotype	CT + TT genotype	OR (95% CI)^a	P
Smoking status	Cases/controls	Cases/controls	OR (95% CI)^a	P
Adenocarcinoma
Nonsmokers	165/381	21/76	0.60 (0.35–1.01)	0.086
Smokers	123/271	10/63	0.34 (0.17–0.69)	0.003
<27 pack-years	56/147	4/41	0.23 (0.08–0.68)	0.008
≥27 pack-years	67/124	6/22	0.47 (0.18–1.25)	0.130
Squamous cell carcinoma
Nonsmokers	44/381	11/76	1.31 (0.64–2.68)	0.456
Smokers	175/271	33/63	0.83 (0.52–1.33)	0.445
<27 pack-years	56/147	10/41	0.65 (0.30–1.40)	0.272
≥27 pack-years	119/124	23/22	1.13 (0.59–2.16)	0.704
Other^b
Nonsmokers	55/381	7/76	0.59 (0.25–1.34)	0.206
Smokers	70/271	10/63	0.62 (0.30–1.28)	0.198
<27 pack-years	29/147	1/41	0.09 (0.01–0.72)	0.023
≥27 pack-years	41/124	9/22	1.25 (0.53–2.97)	0.612
All cases
Nonsmokers	264/381	39/76	0.71 (0.47–1.09)	0.110
Smokers	368/271	53/63	0.62 (0.42–0.93)	0.020
<27 pack-years	141/147	15/41	0.37 (0.19–0.69)	0.002
≥27 pack-years	227/124	38/22	0.95 (0.53–1.69)	0.857

a ORs and 95% CIs were calculated by logistic regression with the CC genotype as reference group and adjusted for age, sex, and pack-years within the strata.
b Other includes undifferentiated cancer (n = 60), bronchioalveolar carcinoma (n = 27), and small cell carcinoma (n = 55).