Abstract P2-01-32: Second sentinel lymph node biopsy for patients with local recurrence after breast cancer surgery
Authors: Park JY , Song JH , Choi JE , Lee SJ 
Published: March 2017

Abstract
Background: Sentinel lymph node biopsy(SLNB) has become standard procedure for primary breast cancer patients who have no tumor metastasis in sentinel lymph node(SLN). In this study, we evaluated feasibility and pathologic outcomes of second SLNB in patients with locally recurrent breast cancer and their follow-up results.
Methods: From January 2008 to December 2015, 114 patients underwent operation for locally recurrent breast cancer. In 42 patients of them, lymphatic mapping was performed for second SLNB. When SLN was visualized in lymphangiography, SLNB was performed. In the cases where SLN metastasis was confirmed, axillary lymph node dissection(ALND) was performed. Follow-up studies were performed every 6 months for 5 years and then annually.
Results: The mean interval to local recurrence from the initial surgery of breast cancer was 64.6±53.1 months. In 38 of 42 patients(90.5%), lymphatic mapping was successfully performed. There was no significant difference of success rate of lymphatic mapping according to previous operation method of breast and axilla or history of radiation therapy.
Aberrant lymphatic pathway was observed in 15 of 38 patients(39.5%). The rate of aberrant lymphatic pathway was higher in patients who underwent ALND previously then in patients who underwent SLNB only(81.8% vs 22.2%, p=0.001). In 6 patients who previously underwent ALND followed by radiation therapy, all their lymphatic pathway was altered. There was no significant difference of the rate of aberrant lymphatic pathway according to previous operation method of breast.
Of 38 patients in whom lymphatic mapping was successfully performed, 37 patients underwent SLNB. SLNs were identified in 31 patients(83.8%). There was no significant difference of success rate of SLNB according to previous operation method of breast and axilla or history of radiation therapy.
Of 31 patients whose SLNs were identified, 4 patients(12.9%) had tumor metastasis in their SLN. Among them, 3 patients underwent ALND but SLN was the only lymph node(LN) in which tumor metastasis was confirmed. The other patient underwent no further ALND because ipsilateral internal mammary LNs were only LNs in which tumor metastasis was confirmed in frozen section biopsy and micrometastasis was additionally confirmed in only one contralateral axillary LN in permanent biopsy.
The mean follow-up period after operation for local recurrence was 33.0±24.5 months. There were 10 cases(23.8%) of loco-regional recurrence or distant metastasis at 14 months of mean follow-up. Among them, one patient had ipsilateral axillary recurrence solitary at 11 months of follow-up. The patient underwent breast conserving surgery and SLNB for primary breast cancer which stage was I. Second SLNB for local recurrence was tried at 48 months after first operation but SLN was not identified. Because there was no evidence of axillary LN metastasis in preoperative image study, no further ALND was performed.
Conclusion: Second SLNB should be considered for patients with locally recurrent breast cancer because occult LN metastasis could be identified in the ipsilateral axilla or other site through aberrant lymphatic pathway. Further studies are needed to verify accuracy of axillary staging using second SLNB and also its oncologic safety.
Citation Format: Park JY, Song JH, Choi JE, Lee SJ. Second sentinel lymph node biopsy for patients with local recurrence after breast cancer surgery [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 P2-01-32.