Audit of local recurrence rates following ‘ultra’-conservative surgery for invasive breast cancer—a boost to the breast?

Abstract

Conservative breast surgery with postoperative radiotherapy and appropriate systemic therapy is associated with similar outcomes when compared with mastectomy. The reported 5 year local recurrence rate varies between 3% and 15%. We prefer a more conservative 'complete' local excision rather than 'wide' local excision combined with post-operative radical radiotherapy and tumour bed boost with the aim of achieving optimal cosmesis. Our review was undertaken to assess whether or not this 'ultra' conservative approach was compromising long-term local control. Case notes and pathology reports of patients who underwent conservative surgery for breast cancer from January 1983 to February 2001 were accessed for this audit. Patient demographic data and tumour characteristics were noted. The primary outcome data were the number of local recurrences following invasive breast cancer at 5 and 10 years and the distance from the tumour to the closest margin of excision. At 5 and 10 years there were 16/451 and 5/124 local recurrences, with a local recurrence rate of 3.5% (95% CI, 1.7-4.7%) and 4.1% (95% CI, 0.47-6.5%), respectively. Complete data with regards to the closest histological margin of excision were available in 423 patients. One hundred and sixty-five patients (39%) had their tumours excised with a distance of less than 1 mm to the closest margin. Nearly, all tumours (97.8%) were excised with the distance to the closest margin less than 1 cm and 81% with 5 mm or less. It is possible to achieve low local recurrence rates after very conservative surgery for breast cancer when this is combined with radical radiotherapy and an additional tumour bed boost.