Table 3.

Odds Ratios for Breast Cancer by Oral Contraceptive Use, According to the Number of Minor Alleles of FGFR2 Single Nucleotide Polymorphisms of rs2303568, rs3135730, and rs1078806, Shanghai Breast Cancer Study, 1996–1998 and 2002–2005

	Number of Minor SNP Alleles												P for Interaction
	0				1a				2
	No. of Cases	No. of Controls	ORb	95% CI	No. of Cases	No. of Controls	ORb	95% CI	No. of Cases	No. of Controls	ORb	95% CI
rs755793
OC use
Never	1,421	1,444	1.00		230	209	1.00
Ever	348	388	0.95	0.80, 1.12	71	37	1.83	1.14, 2.94					0.01
Duration of OC use
<18 months	175	201	0.92	0.74, 1.15	33	23	1.32	0.72, 2.40
≥18 months	173	187	0.98	0.78, 1.24	38	14	2.70	1.38, 5.29					0.011
P for trend			0.69				0.0038
rs2303568
OC use
Never	1,321	1,349	1.00		226	211	1.00
Ever	302	336	0.94	0.78, 1.13	73	37	2.04	1.26, 3.29					0.005
Duration of OC use
<18 months	153	172	0.93	0.73, 1.17	34	21	1.63	0.88, 3.00
≥18 months	149	164	0.96	0.75, 1.23	39	16	2.62	1.36, 5.05					0.011
P for trend			0.59				0.002
rs3135730
OC use
Never	1,318	1,337	1.00		234	225	1.00
Ever	299	332	0.93	0.78, 1.12	76	43	1.97	1.25, 3.12					0.007
Duration of OC use
<18 months	150	169	0.92	0.72, 1.16	37	25	1.61	0.90, 2.87
≥18 months	149	163	0.96	0.75, 1.22	39	18	2.51	1.33, 4.75					0.017
P for trend			0.56				0.002
rs1078806
OC use
Never	785	824	1.00		708	679	1.00		161	154	1.00
Ever	199	232	0.94	0.75, 1.18	172	172	0.99	0.77, 1.26	48	22	2.11	1.19, 3.76	0.016
Duration of OC use
<18 months	100	112	0.96	0.72, 1.29	89	98	0.91	0.67, 1.25	19	15	1.06	0.50, 2.27
≥18 months	99	120	0.92	0.68, 1.24	83	74	1.09	0.77, 1.54	29	7	4.52	1.88, 10.87	0.008
P for trend			0.55				0.86				0.0016

Abbreviations: CI, confidence interval; OC, oral contraceptive; OR, odds ratio.

^a Number of minor alleles ≥1 for rs2303568 and rs3135730.

^b Adjusted for age, educational level, age at menarche, menopausal status, breast cancer in first-degree relatives, number of livebirths, and body mass index.