Margin status after breast-conserving treatment of breast cancer: how much free margin is enough?

In breast conserving surgery the margins of the specimen have to be tumor free. There is no universal agreement on the width of the tumor free margin. The width has some impact on recurrence rate, and at least 5 mm seems to be preferred and this is especially important in extensive intraductal component. In ductal cancer in situ the free margin should be at least 5 mm, preferably 10 mm. Oncoplastic surgery is beneficial for reaching adequate margins.