Table 2 Unadjusted odds ratios, P values and discriminatory capacity (AUC) for the standard risk factors considered for our study population

Age at menarche (ordinal)

0.54 (0.49–0.60)

 Reference group: under age 12 years

1

–

(N/A)

 Between ages 12 and 14 years

0.57

0.01

(0.37–0.88)

 Age 15 years and older

0.32

0.01

(0.13–0.78)

Number of benign biopsies (ordinal)

0.52 (0.47–0.57)

 Reference group: 0 biopsies

1

–

(N/A)

 1 biopsy

1.05

0.76

(0.75–1.48)

 2 or more biopsies

1.11

0.76

(0.56–2.19)

First-degree family history (ordinal)

0.51 (0.46–0.56)

 Reference group: 0 relatives

1

–

(N/A)

 1 relative

0.93

0.77

(0.57–1.51)

 2 or more relatives

0.86

0.77

(0.33–2.29)

Age at first live birth (nominal)

0.56 (0.50–0.61)

 Reference group: nulliparous women

1

–

(N/A)

 Prior to age 30 years

1.88

0.04

(1.04–3.42)

 At age 30 years or older

2.00

0.05

(1.00–3.99)

Race (nominal)

0.60 (0.54–0.65)

 Reference group: Caucasian

1

–

(N/A)

 African-American

0.60

0.07

(0.34–1.03)

 Asian

0.40

0.24

(0.08–1.84)

 Other

0.78

0.72

(0.20–3.04)

Body mass index (ordinal)

0.76 (0.71–0.81)

 Reference group: normal

1

–

(N/A)

 Overweight

2.97

<0.001

(2.17–4.05)

 Obese

8.81

<0.001

(4.72–16.4)