Table 4.

Association^a Between the Sex Hormone-Binding Globulin (SHBG) rs6259 Polymorphism and Breast Cancer Risk According to Body Mass Index, by Study Stage, Shanghai Breast Cancer Study, 1996–2005

Study and Genotype	Premenopausal Women						Postmenopausal Women						All Womenb
	BMIbc <23			BMI ≥23			BMI <23			BMI ≥23			BMI <23			BMI ≥23
	Cases/ Controlsd	OR	95% CI	Cases/ Controls	OR	95% CI	Cases/ Controls	OR	95% CI	Cases/ Controls	OR	95% CI	Cases/ Controls	OR	95% CI	Cases/ Controls	OR	95% CI
Stage 1 (SBCS I; 1996–1998)
GG	282/301	1.0	Reference	215/212	1.0	0.8, 1.3	101/100	1.0	Reference	164/178	0.9	0.7, 1.3	384/402	1.0	Reference	380/392	1.0	0.8, 1.2
AG/AA	115/137	0.9	0.7, 1.2	123/98	1.2	0.9, 1.7	24/63	0.4*	0.2, 0.7	75/84	0.9	0.6, 1.4	140/200	0.7*	0.6, 1.0	198/185	1.1	0.9, 1.4
P for interaction	0.160						0.005						0.024
Stage 2 (SBCS II; 2002–2005)
GG	390/353	1.0	Reference	359/282	1.2	0.9, 1.4	208/234	1.0	Reference	381/380	1.1	0.9, 1.4	598/588	1.0	Reference	740/662	1.2	1.0, 1.4
AG/AA	148/154	0.9	0.7, 1.1	182/123	1.4*	1.0, 1.8	85/128	0.8	0.5, 1.0	161/161	1.1	0.9, 1.5	233/282	0.8	0.7, 1.0	343/284	1.2*	1.0, 1.5
P for interaction	0.135						0.144						0.046
SBCS I and SBCS II combined
GG	672/654	1.0	Reference	574/494	1.1	0.9, 1.3	309/334	1.0	Reference	545/558	1.1	0.9, 1.3	982/990	1.0	Reference	1,120/1,054	1.1	1.0, 1.2
AG/AA	263/291	0.9	0.7, 1.1	305/221	1.3*	1.1, 1.6	109/191	0.6*	0.5, 0.8	236/245	1.1	0.8, 1.3	373/482	0.8*	0.7, 0.9	541/469	1.2*	1.0, 1.4
P for interaction	0.044						0.007						0.003

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio; SBCS, Shanghai Breast Cancer Study.

*P ≤ 0.05.

^aOdds ratios and 95% confidence intervals from dominant effect models, adjusted for age.

^bNumbers of premenopausal and postmenopausal women do not sum to those for all woman because some participants were missing information on menopausal status.

^cWeight (kg)/height (m)².

^dNo. of cases/no. of controls.