الفهرس 
Title : Predictors of local recurrence after breast conservative surgery following neoadjuvant chemotherapy
ContantsOnly 14 pages are availabe for public view
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Abstract
Background: The aim of BCS after NAC is complete excision of the tumor with an adequate margin, however, no clear definition of what constitutes a clear margin has been proposed. An additional challenge for surgeons is the extent of resection especially in good responders to NAC.
Objectives: The objective of this study is to determine the impact of an adequate clear surgical margin on local recurrence after BCS for patients who responded to NAC. Also, other factors affecting LRFS, DFS and OS are considered.
Patients and Methods: This study is a prospective observational cohort study conducted at the National Cancer Institute which included 75 Egyptian female breast cancer patients who responded to NAC and then assigned to BCS in the period from October 2019 till October 2020. Patients were assessed with regular appointments at the outpatient clinics up to 2 years follow up after surgery.
Results: The mean age was 43.8±9.5 years and 65.3 % of patients were in the premenopausal status. All patients (75 cases) had either cT2 or cT3 disease. Clinical nodal disease (cN1-3) was found in 68 patients (90.7%). Positive nodal involvement was confirmed in 22 patients (29.3%). Over 70% of patients had ypT stage 1c or 2 and over 60 % of patients had ypN stage 0. Miller-Payne Grade 4 or 5 were detected in 48 patients (64%). By the end of follow up, four patients developed local recurrence, nine patients developed distant metastases, and seven patients had died (from distant metastasis). The unadjusted local recurrence rate was 5.3% and cumulative local recurrence free survival of the whole studied group at 36 months was 94.6%. The least circumferential resection margin (2mm) had no impact on LRFS, DFS or OS. The only factors that affected LRFS were the ypT stage (p < 0.001) and ypN stage (p=0.042). Earlier ypT stage, ypN stage, and higher Miller-Payne grade were associated with significantly better DFS. However, the survival analysis for ypT0 was worse compared to ypT1-3 which could be explained by the phenomenon of “pCR paradox”. DFS was significantly better (p=0.036) in patients with clinical N0 or N1 compared to those with N2 or N3 disease . OS was significantly better (p=0.008) in patients with clinical N0 or N1 than those with N2 or N3 disease.
Conclusion: The clinical lymph node (cN) stage, post neoadjuvant pathologic (ypTN) stage and pathologic complete response (pCR) were the most significant factors in terms of survival. The least circumferential resection margin (2mm) had no impact on LRFS, DFS or OS which suggests that a margin of ‘‘no ink on tumor’’ may be acceptable in NAC-BCS patients, however, further studies with larger sample size and longer duration of follow up are required to mitigate the local recurrence after breast conservative surgery following neoadjuvant chemotherapy.