[Summary of the Dutch College of General Practitioners' practice guideline 'Diagnosis of breast cancer'].

The general practitioner should encourage women aged 50-75 who are eligible for the national screening program for the early detection of breast cancer to participate. When any abnormalities are seen on the mammogram, the general practitioner should refer the woman for further investigations and inform her about the procedure to be followed. In the case of a lump, a mammogram or ultrasound examination of the breasts is indicated, unless the abnormality disappears during a different phase of the woman's menstrual cycle. Local pain and brown or bloody discharge from the nipples also necessitate further investigation. Women with a greater than 20% risk of ever developing breast cancer during their life based on a positive family history for breast cancer have an indication for periodic examination of the breasts and a mammogram before they are 50. If the risk is greater than 30%, consultation with a clinical geneticist can be suggested.