Table 1. Comparison of risk factors at diagnosis between tumour locations. Data are presented as proportion of individuals within each category.

	UOQ (n = 520)	UIQ (n = 158)	LOQ (n = 143)	LIQ (n = 82)	Central (n = 107)	P value
Age at Diagnosis
<40 years	0.06	0.04	0.05	0.07	0.03	0.115
40–49 years	0.20	0.22	0.29	0.12	0.20
≥50 years	0.74	0.74	0.66	0.81	0.77
Menopausal status
Pre-menopausal	0.29	0.28	0.36	0.25	0.23	0.190
Post-menopausal	0.71	0.72	0.64	0.75	0.77
Ethnicity
African American	0.20	0.21	0.17	0.21	0.13	0.420
Asian	0.01	0.03	0.01	0.01	0.03
Hispanic	0.01	0.01	0.01	0.01	0.04
Other	0.01	0.01	0.01	0.00	0.00
Caucasian	0.77	0.74	0.80	0.77	0.80
BMI
<18.5	0.01	0.01	0.01	0.01	0.01	0.247
18.5–24.9	0.32	0.24	0.31	0.25	0.38
25–29.9	0.29	0.36	0.27	0.34	0.37
≥30	0.38	0.39	0.41	0.40	0.24
Breastfeeda
Yes	0.46	0.44	0.47	0.53	0.49	0.616
No	0.54	0.56	0.53	0.47	0.51

^aBreastfeeding was considered only in parous women.