Table 2.

Risk Estimates for Pancreatic Cancer Associated With Cigarette Smoking in the Pooled Study Population, With Never Smokers as the Reference Group

Smoking Exposure	No. of Cases	No. of Controls	ORa	95% CI
Never smoker	582	678	1.00	Referent
Ever smoker	899	861	1.24	1.06, 1.46
Current	433	362	1.77	1.38, 2.26
Former	466	499	1.09	0.91, 1.30
Intensity, cigarettes/day
<10	142	149	1.18	0.91, 1.55
10–<20	252	239	1.33	1.05, 1.67
20–<25	150	145	1.30	0.98, 1.72
25–<30	70	68	1.28	0.88, 1.88
≥30	121	84	1.75	1.27, 2.42
Ptrend			<0.001
Duration, years
≤10	86	93	1.08	0.79, 1.49
>10–20	113	139	0.96	0.72, 1.27
>20–40	406	378	1.30	1.06, 1.60
>40–50	161	134	1.59	1.20, 2.11
>50	39	24	2.13	1.25, 3.62
Ptrend			<0.001
Pack-years
≤10	149	165	1.11	0.85, 1.43
>10–20	121	115	1.32	0.98, 1.77
>20–30	127	125	1.30	0.97, 1.75
>30–40	119	107	1.49	1.08, 2.03
>40	194	146	1.78	1.35, 2.34
Ptrend			<0.001
Years since quitting
1–<10	40	20	2.19	1.25, 3.83
10–<15	40	37	1.24	0.78, 1.98
15–<20	36	47	0.91	0.58, 1.44
20–<30	81	104	0.91	0.66, 1.26
≥30	154	198	0.93	0.73, 1.20
Ptrend			<0.001
1–<10b	40	20	1.24	0.69, 2.22
10–<15	40	37	0.70	0.43, 1.16
15–<20	36	47	0.52	0.32, 0.85
20–<30	81	104	0.52	0.36, 0.75
≥30	154	198	0.53	0.39, 0.73
Ptrend			<0.001
Age at start, yearsc
<15	68	64	1.24	0.85, 1.79
15–<20	361	346	1.27	1.03, 1.56
≥20	410	381	1.28	1.06, 1.56
Ptrend			0.97

Abbreviations: CI, confidence interval; OR, odds ratio.

^aModels were adjusted for age, sex, study center, diabetes, body mass index, and race.

^bYears since quitting using current smokers as the reference group.

^cData were missing for the CLUE II study.