Table 1 Characteristics of women with breast cancer and their matched controls

Hypothesised risk factors

   Absolute breast volume FA (ml; median (IQR))

   Relative breast volume FA (%; median (IQR))

Other potential risk factors/confounders

   BMI (n = 503; mean (SD))

   Height (cm; mean (SD))

   Age at menarche (years; n = 503; mean (SD))

   Age at 1st pregnancy (years; n = 400; mean (SD))

   Number of pregnancies (n = 503; median (IQR))

   Family history

   Mean breast volume (ml; median (IQR))

   Parenchyma type: right breast

N1

P1

P2

DY

   Parenchyma type: left breast

N1

P1

P2

DY

   Menopausal status (n = 482)

Pre

Peri

Post

   Age at menopause (years; n = 212; median (IQR))