Table IV.

Urinary total NNAL and total cotinine, cigarette smoking and alcohol consumption in relation to risk of esophageal cancer among current smokers, The Shanghai Cohort Study 1986–2008

	No. of cases	No. of controls	Matched OR (95% CI)	Total NNN-adjusted OR (95% CI)a
Urinary total NNAL (fmol/mg creatinine)b
First tertile (<278)	14	69	1.00 (referent)	1.00 (referent)
Second tertile (278–522)	23	71	1.69 (0.79–3.64)	1.00 (0.42–2.41)
Third tertile (>522)	37	69	3.63 (1.60–8.21)	1.01 (0.36–2.87)
P for trend			0.002	0.98
Urinary total cotinine (nmol/mg creatinine)
First tertile (<7.13)	16	74	1.00 (referent)	1.00 (referent)
Second tertile (7.13–15.64)	25	76	1.61 (0.78–3.33)	0.53 (0.21–1.32)
Third tertile (>15.64)	36	73	2.46 (1.22–4.99)	0.41 (0.15–1.15)
P for trend			0.011	0.11
No. of cigarettes per day
<10	8	36	1.00 (referent)	1.00 (referent)
10 to <20	21	79	1.14 (0.46–2.85)	0.73 (0.26–2.05)
20+	48	108	1.85 (0.80–4.29)	1.17 (0.45–3.09)
P for trend			0.058	0.34
No. of years of smoking
<20	9	32	1.00 (referent)	1.00 (referent)
20 to <40	34	140	0.98 (0.39–2.46)	0.93 (0.31–2.75)
40+	34	51	4.48 (1.48–13.7)	6.06 (1.58–23.2)
P for trend			0.001	0.001
No. of drinks of alcoholic beverages per day
Non-drinkers	19	91	1.00 (referent)	1.00 (referent)
<2	17	64	1.43 (0.65–3.12)	1.74 (0.68–4.45)
2 to <4	21	43	2.56 (1.17–5.61)	3.34 (1.28–8.74)
4+	20	25	4.24 (1.87–9.61)	5.15 (1.97–13.5)
P for trend			<0.001	<0.001

^aIn addition to matching factors, ORs were adjusted for urinary total NNN and the percentage of NNN-N-Gluc.

^bThree cases and 14 controls (nine who were individually matched controls of these three cases and five additional controls with missing values on total NNAL) were excluded from this analysis using conditional logistic regression models.