Tumour bed positivity predicts outcome after breast-conserving surgery

Local recurrence after breast-conserving surgery is associated with a short distant disease-free survival, particularly if it occurs early. Early recurrence is caused by residual disease left at the time of surgery. Previous studies have demonstrated that disease in the tumour bed is a common finding after breast-conserving surgery.

The follow-up (mean 4.4 years) of 300 patients who had tumour bed analysis performed by the cavity shaving technique following breast-conserving surgery is presented. Postoperative radiotherapy was administered to all patients.

The incidence of tumour bed positivity was 39.3 per cent. With a selective re-excision policy the local recurrence rate was 2.0 per cent and distant recurrence rate 10.4 per cent. Multivariate analysis identified lymphovascular invasion, oestrogen receptor status and tumour bed status as independent predictors of time to distant recurrence.

A low rate of local recurrence can be achieved using this technique of margin assessment. Tumour bed status may be a useful prognostic factor following breast-conserving surgery.