[Risk of breast cancer].

The factors that influence the risk of breast cancer are vitally important when collecting information on woman particularly at risk from cancer for screening and for advisory care in breast clinics. On the basis of the experience gathered over the last 150 years (since Rigoni-Stern in 1842), these should be divided up into I. confirmed (carcinoma of the breast, mastopathy with cytological atypia, women whose mother and sisters already had breast cancer), II. probable (childlessness, late first birth, miscarriage, early menarche and late menopause, overweight, elevated socio-economic status), and III. improbable risk factors (paranchyma samples according to Wolfe, the contraceptive pill, nicotine, coffee, alcohol and drugs).