Abstract P2-01-37: Technical feasibility and validity of sentinel lymph node biopsy in patients with ipsilateral breast tumor recurrence

Abstract

Abstract Background: The incidence of ipsilateral breast tumor recurrence (IBTR) was reported to be approximately 5-10% of breast cancer patients who had breast-conserving surgery. However, the role of sentinel lymph node biopsy (SLNB) in patients with IBTR still remains to be elucidated. The aim of this study wasto evaluate feasibility and validity of sentinel lymph node biopsy for ipsilateral breast tumor recurrence (second SLNB). Patients and methods: A prospective database of 1607 patients with clinically node-negative breast cancer who underwent SLNB from January 2005 to May 2015 was analyzed and 46 patients with IBTR underwent SLNB. Lymphatic mapping was performed using a combined method of blue dye and radioisotope. ICG fluorescence imaging was performed in cases with failure of identification by blue dye and radioisotope. Results: The median age was 52 (range: 36-82) years at the time of second SLNB and the mean size of recurrent tumor was 1.39 ± 0.63 cm. Thirty-one (67.4%) and 10 (21.7%) patients had a history of previous SLNB and axillary lymph node dissection (ALND), respectively. Another five (10.9%) patients had no previous axillary surgery for primary tumors. Preoperative lymphatic mapping by lymphoscintigraphy was successfully performed in 24 of 36 patients (66.7%). The identification rate by lymphoscintigraphy among patients with previous SLNB, ALND, and no axillary surgery was 64.0% (16/25), 66.6% (6/9) and 100% (2/2), respectively (P= 0.583). Overall, sentinel lymph nodes (SLNs) were successfully identified in 37 (80.4%) of 46 patients during surgery. The identification rate in patients with previous SLNB, ALND and no axillary surgery was 80.6% (25/31), 80.0% (8/10) and 80.0% (4/5), respectively (P=0.990). The aberrant lymphatic drainage to extra-ipsilateral axilla was found more frequently in patients with previous ALND compared with previous SLNB and no axillary surgery (40.0% vs. 6.5% vs. 0%, P=0.015).Among three (6.5%) patients with SLN metastases, one patient with previous SLNB had macrometastasis at the ipsilateral axilla and ALND found a positive non-SLN (1/21). The remaining two patients with previous SLNB and ALND had micrometastases at ipsilateral and contralateral axilla, respectively and both patients underwent no further axillary treatment. After second SLNB, systemic treatment including chemotherapy, endocrine therapy and trastuzumab was performed in 17 (37.0%), 36 (78.3%) and seven (15.2%) patients, respectively. No axillary recurrence was observed after a median follow-up time of 37.2 months from surgery for IBTR. Conclusions: Second SLNB is technically feasible regardless of types of previous axillary surgery and may avoid complications from unnecessary ALND for IBTR. Furthermore, it could improve risk prediction for IBTR and provide valid information for deciding adjuvant therapy. Citation Format: Matsumoto A, Jinno H, Yanagisawa T, Yoshikawa M, Takahashi Y, Seki T, Takahashi M, Hayashida T, Ikeda T, Kitagawa Y. Technical feasibility and validity of sentinel lymph node biopsy in patients with ipsilateral breast tumor recurrence [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-37.