Repeat surgery following breast conservation and intra-operative sentinel lymph node analysis for breast cancer.

Introduction: Intra-operative sentinel node analysis (IOA) for breast cancer reduces the need for a second operation by revealing metastasis intra-operatively, allowing immediate axillary clearance. Critics argue that the number of patients deriving benefit is limited, as further surgery is often required for reasons other than nodal status.

Aim: To identify the proportion of women avoiding further surgery by using IOA excluding those who require further surgery for reasons other than axillary node metastasis.

Patients And Methods: All patients undergoing sentinel node biopsy with IOA over one year were reviewed. Patient demographics, margin positivity, sentinel node metastasis, requirement for further surgery, and cavity shave involvement were analysed.

Results: 322 patients were analysed: 253 undergoing breast-conserving surgery [BCS] and 69 undergoing mastectomy). IOA revealed metastasis in 81 (25.2.%) patients [25 undergoing mastectomy and 56 undergoing BCS], who underwent immediate axillary clearance. 43 BCS patients (17%) did not require further surgery other than for sentinel node involvement. 39 patients required further oncological surgery: 16 excision of margins; 13 completion mastectomy; 6 excision of margins followed by mastectomy; 3 completion axillary clearance; and 1 excision of recurrence. 20.6% had involvement of any circumferential histological margin. Cavity shaves were performed in 28.5% patients at initial surgery, the majority of which were clear of malignancy. 20 mastectomy patients had concordant definitive histology, avoiding a second operation. In total, 19.6% of this cohort avoided a second operation through the use of IOA.

Discussion: Approximately 15% of patients undergoing breast conservation surgery for breast cancer require further surgery. However, a further 17% were saved subsequent surgery by utilising IOA, since they had immediate axillary clearance. When also considering patients undergoing mastectomy, this proportion is even higher.