GEC-ESTRO APBI classification as a decision-making tool for the management of 2nd ipsilateral breast tumor event

Abstract

AimSecond ipsilateral breast tumor event (2ndIBTE) occurring after primary radio-surgical treatment can be treated by either salvage mastectomy or 2nd conservative treatment (2ndCT) including an accelerated partial breast re-irradiation (APBrI). We analyzed the impact of the GEC-ESTRO APBI classification (GAC) on the oncological outcome after APBrI.Materials and methodsBetween 2000 and 2016, 159 patients (pts) underwent a 2ndCT. After lumpectomy, APBrI was performed using either low-dose (30–55\xa0Gy reference isodose) or high-dose rate brachytherapy (28–34\xa0Gy). Oncological outcome including 3rdIBTE, regional (RFS) or metastasis-free survival (MFS), specific (SS) and overall survival (OS) was analyzed according to GAC. Univariate (UVA) and multivariate analyses (MVA) were conducted to identify significant prognostic factors for 3rdIBTE.ResultsWith a median follow-up of 71\xa0months (range 62–85\xa0months), 60 pts (42%), 61 pts (42.7%) and 22 pts (15.4%) were classified as low-risk (LR), intermediate-risk (IR) and high-risk (HR), respectively. For the whole cohort, 6-year 3rdIBTE-free survival, RFS, MFS, SS and OS rates were 97.4, 96.4, 90.3, 92.9 and 91.2%, respectively. Six-year 3rdIBTE-free survival rates for LR, IR and HR were 100, 95.8 and 92.9%, respectively (p\u2009=\u20090.003), while no significant differences were found between the three GAC groups for RFS, MFS, SS. In UVA, lympho-vascular invasion (p\u2009=\u20090.009), positive margins (p\u2009=\u20090.0001) and GAC high-risk group (p\u2009=\u20090.001) were considered as significant prognostic factors for 3rdIBTE, while, in MVA, high-risk group (p\u2009=\u20090.009) was the only prognostic factor.ConclusionIn case of 2ndIBTE, GAC could be used as a decision helping tool to discuss conservative or radical treatment options. Patient information remains crucial in order to accurately define the salvage therapy modalities.