Table 2.

Reproductive factors and female hormone use in relation to risk of pancreatic cancer

Reproductive factors	Controls	Patients	OR (95% CI)a	Multivariable-adjusted ORb (95% CI)
Age at menarche (years)
<12	249	75	1.0 (ref)	1.0 (ref)
12	272	70	0.8 (0.6–1.2)	0.9 (0.6–1.3)
13–14	425	108	0.8 (0.6–1.2)	0.8 (0.6–1.2)
≥15	132	27	0.7 (0.4–1.1)	0.6 (0.4–1.1)
p for trend				0.105
Age at first birth (years)
Nulliparous	182	36	1.0 (0.6–1.6)	1.2 (0.7–2.1)
<20	194	41	1.0 (ref)	1.0 (ref)
20–24	392	102	1.3 (0.8–1.9)	1.5 (0.9–2.3)
25–29	215	70	1.6 (1.0–2.5)	2.1 (1.3–3.4)
≥30	113	35	1.5 (0.9–2.5)	2.0 (1.1–3.3)
p for trend				0.042
Number of years of oral contraceptive use (years)
No-use	816	200	1.0 (ref)	1.0 (ref)
>0 to <1	81	20	1.1 (0.6–1.9)	1.0 (0.6–1.9)
1 to <5	113	30	1.2 (0.8–1.9)	1.3 (0.8–2.2)
5 to <10	46	17	1.7 (0.9–3.2)	1.8 (1.0–3.5)
10+	40	17	2.0 (1.1–3.8)	2.0 (1.0–4.0)
p for trend				<0.01
Age at menopausec
<45	164	41	1.0 (ref)	1.0 (ref)
45–49	188	52	1.0 (0.6–1.6)	1.0 (0.6–1.7)
≥50	453	120	1.0 (0.7–1.5)	1.1 (0.7–1.8)
p for trend				0.259
Number of years of hormone use (years)
No-use	880	235	1.0 (ref)	1.0 (ref)
>0 to <1	68	19	1.0 (0.6–1.8)	1.0 (0.6–1.8)
1 to <5	66	14	0.8 (0.4–1.4)	0.8 (0.4–1.5)
≥5	82	16	0.7 (0.4–1.2)	0.7 (0.4–1.2)
p for trend				0.599
Parity
Nulliparous	182	36	1.0 (ref)	1.0 (ref)
1–2	418	120	1.5 (1.0–2.2)	1.5 (1.0–2.3)
3–4	327	87	1.4 (0.9–2.2)	1.4 (0.9–2.2)
≥4	143	37	1.3 (0.8–2.2)	1.5 (0.8–2.6)
p for trend				0.411

^aAdjusted for age group (5-year age interval), study center, year of interview (5-year categories), and race (white, black)

^bAdjusted for age, study center, race, interview year, years of education, body mass index, cigarette (never, ex-smoker, current smoker), alcohol consumption (never, ex-drinker, current drinker), history of diabetes (no/yes), and other reproductive factors or female hormone use

^cAmong postmenopausal women only