Local treatment of ipsilateral breast recurrences: a comparative analysis of alternative therapeutic options
Smanykó Viktor
Pathological Sciences
Dr. Matolcsy András
Országos Onkológiai Intézet
2023-10-02 14:00:00
Experimental Oncology
Dr. Bödör Csaba
Dr. Polgár Csaba
Dr. Szász Attila Marcell
Dr. Bellyei Szabolcs
Dr. Lotz Gábor
Dr. Varga Linda
Dr. Tőkés Anna Mária
Background: In spite of appropriate local treatment of early-stage breast cancer, the rate of ipsilateral breast tumor recurrence (IBTR) has been reported to be within the range of 10 to 15% in 20 years. In these cases, salvage mastectomy (sMT) is historically considered as the gold standard treatment, but subsequently patients suffer from significantly reduced emotional and social functions. The recurrence rate after a second breast-conserving surgery (2ndBCS) alone is unacceptably high, and a second course of irradiation to the whole remaining breast with an adequate dose is considered inappropriate due to the high risk of severe late side effects.
Purposes: To report the (1.) dosimetric results (2.), clinical outcomes, and (3.) late side effects and cosmetic results of second breast conserving therapy (2ndBCT) with perioperative high-dose-rate multicatheter interstitial brachytherapy (HDR MIBT) versus sMT for the treatment of IBTR.
Material and methods: Between 1999 and 2015, 195 patients who presented with an IBTR after previous breast-conserving treatment were salvaged either with re-excision and perioperative HDR MIBT (n=39) or sMT (n=156). In the 2ndBCT group a total dose of 22 Gy in 5 fractions of 4.4 Gy was delivered to the tumour bed with intraoperatively implanted catheters for 3 consecutive days.
Results: (1.) With the technique of intraoperative catheter implantation, the dose exposure of the organs at risk can be kept at a sufficiently low level. The dosimetric results were consistent with those observed previously with HDR MIBT for primary breast cancer executed by postoperative implantation technique, but the intraoperative method doesn’t need a second invasive intervention for the patients.
(2.) The median follow-up time was 59 months (1-189) in the 2ndBCT and 56 months (3-189) in the sMT group. The mean size of IBTR was 16 mm (2-70) vs. 24 mm (2-90), respectively (p=0.0005), but there was no any other significant difference in pathological related parameters (histologic type and grade, margin status, receptor status) or in patient related parameters (age, menopausal status, mean time to recurrence), between the two groups.
During the follow-up period, 4 out of 39 (10.2%) and 28 out of 156 (17.9%) 2ndIBTR occurred in the 2ndBCT and the sMT group, respectively. The 5-year actuarial rate of 2ndIBTR was 6% vs. 18% (p=0.16), respectively. The 5-year probability of regional recurrence-free survival, distant metastasis-free survival, disease-free survival, cancer-specific survival and overall survival was 94% vs. 95% (p=0.62), 76% vs. 74% (p=0.41), 69% vs. 65% (p=0.20), 85% vs. 78% (p=0.51), and 81% vs. 66% (p=0.12), in the same order.
(3.) After the 2nd BCT, 70% of the patients had excellent or good cosmetic results based on the Harvard criteria. Grade 3 late skin toxicity occurred in 3 patients, and grade 3 fibrosis detected in 1 woman. Fat necrosis developed only in an asymptomatic form.
Conclusions: This study was the first, which directly comparing 2ndBCT to sMT in patients who were treated at the same institute and during the same period. Based on our results, 2ndBCT with perioperative HDR MIBT is a safe and feasible option for the management of IBTR, resulting in equivalent 5-year oncological outcomes and better cosmetic results compared to sMT.
