[Secondary breast operations are often necessary and are no indication of poor oncological quality]

The most important factor for tumour recurrence after breast-saving surgery is the margin status. In the Netherlands a 1-mm free margin has been formulated as sufficient, and totally free margins are not necessary in all cases. The current Dutch Health Inspectorate performance indicator, i.e. 10% reexcisions allowed to achieve free margins, is a performance indicator of questionable validity. As long as there is worldwide discussion about the ideal margin in breast-saving surgery a specific norm cannot not be dictated. The aim of the discussion should be how to prevent local recurrence. This percentage is the real performance indicator.