Impact of margin status on ipsilateral breast tumor recurrence after breast-conserving treatment for patients with breast cancer who received neoadjuvant chemotherapy: a retrospective multi-institutional study of 1813 cases.

BACKGROUND

There is no consensus regarding the optimal margin status among patients with breast cancer treated with neoadjuvant chemotherapy (NAC), breast-conserving surgery, and radiotherapy (breast-conserving treatment [BCT]).

METHODS

In total, 1813 patients with newly diagnosed stage 1-3 breast cancer who underwent BCT after NAC were evaluated to determine the impact of margin status on ipsilateral breast tumor recurrence (IBTR).

RESULTS

During a median follow-up period of 8.0 years (range 0.1-17.0 years), the 8-year IBTR-free survival rate was 95.9%. Patients with positive margins had significantly worse IBTR-free survival than those with negative margins (8-year IBTR-free survival rate: 87.6% vs. 96.2%, p = 0.010). Multivariate analysis showed that margin status was significantly associated with IBTR-free survival (hazard ratio: 3.1; 95% confidence interval 1.3-7.2; p = 0.0081).

CONCLUSIONS

This multicenter retrospective study demonstrated that margin status is significantly associated with IBTR-free survival in patients who received NAC and BCT, consistent with findings in upfront-surgery cases.