Re-excision rate after sector resection for breast cancer: A 5-year retrospective cohort study.

BACKGROUND: Positive margins after Breast conserving surgery (BCS) for breast cancer can result in local recurrence (LR) requiring further surgery. This can lead to unnecessary patient anxiety, poor prognosis and impose additional economic burden to our health system. The aim of this study is to assess the rate of re-excision for positive margins after BCS using the sector resection technique.

METHODS: This single centre retrospective cohort study included all women who underwent BCS using sector resection between the years of 2012 and 2016. A total of 456 patients underwent sector resection. We evaluated the margin status, re-excision rates and their predictive risk factors.

RESULTS: 415 (91%) patients had clear margins. 41 (9%) patients underwent further re-excision for positive or close margin. 75.6% of those patients had DCIS and 51% had invasive carcinoma involving the margins. Patient and tumour characteristics associated with an increased risk of positive margin were women under the age of 50 (p = 0.19), tumours >50 mm (p = 0.001), grade-2 (p = 0.48) and grade-3 (p = 0.63), HER-2 positivity (p = 0.02), sentinel lymph node positivity (p = 0.03), and patients undergoing axillary lymph node dissection (p = 0.01).

CONCLUSION: BCS using the sector resection technique has a low re-excision rate for positive margins. Younger patients and aggressive tumour biology are important predictive risk factors for positive margins.