Performance and oncologic safety of sentinel lymph node biopsy after neoadjuvant chemotherapy: Results from a tertiary care center in Lebanon.

BACKGROUND: The feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) in initially node-positive patients is still controversial. We aim to evaluate the oncologic outcomes of SLNB after NACT and further compare the results between those who were initially node-negative and node-positive.

METHODS: This is a retrospective cohort that included patients diagnosed with invasive breast cancer and had surgical management between January 2010 and December 2016. Survival and recurrence data after 3-5 years were collected from patients' records. We divided patients into Group A who were initially node-negative and had SLNB ± axillary lymph node dissection (ALND) and Group B who were node-positive and had SLNB ± ALND.

RESULTS: Among initially node-negative patients, 43 out of 63 patients did SLNB (Group A). However, among initially node-positive patients only 28 out of 123 patients did SLNB (Group B). Out of the 71 patients who did SLNB after NACT, 26 patients had positive SLNs with only 14 patients who further underwent ALND. The identification rate of SLNB was 100% in Group A and 96.4% in Group B. The survival curves by nodal status showed no significant difference between overall survival and recurrence-free survival at 5 years between patients in Group A versus Group.

CONCLUSION: The results suggest that in properly selected patients, SLNB can be feasible after NACT. Our results resemble the reported literature on accuracy of SLNB after NACT and adds to the growing pool of data on this topic.