Abstract P4-07-59: Management of Isolated Contralateral Axillary Lymph Node Metastasis in Breast Cancer: A Single Institution Experience
Authors: Patel Rima , Berwick Shana , Jin Cao , Klein Paula 
Published: March 2023

Abstract
Background: Contralateral axillary lymph node metastasis (CAM) in breast cancer (BC) is uncommon with an incidence of 1.9-6%. It is considered as stage IV disease based on the TNM classification in the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual. However, in the absence of other distant metastases, patients with CAM have been found to have better outcomes compared to those with stage IV disease. Recent studies suggest that CAM may represent locoregional spread of tumor through lymphatics rather than hematogenous spread and patients should be classified as N3 rather than M1. There are no clear guidelines on the optimal management of these patients and it is unclear if patients with isolated CAM should be treated as curative intent or as metastatic disease with palliative treatment. The goal of this study was to describe the management and outcomes of patients with BC and isolated CAM seen at our institution.
Methods: We performed a retrospective chart review on all patients with BC and isolated CAM but no other distant metastases who were seen at our institution between 2000-2021. We collected information on demographics, tumor characteristics, intent of therapy (curative versus palliative), types of treatment (systemic treatments including chemotherapy (CT), hormone therapy, targeted therapy; radiation therapy; surgery), and response to frontline treatment.
Results: We identified a total of ten eligible patients who were diagnosed between 2011-2020. The median age of diagnosis was 57 years and 70% had de novo cancers while the remainder had recurrent disease. The table below describes each patient’s cancer, treatment, and response. Patients are listed in chronological order, with those at the top diagnosed in 2011 and bottom in 2020. Four patients had hormone receptor (HR)-positive and HER2-negative BC, 3 patients had triple negative BC, 2 had HER2-positive BC and 1 had HR-positive and HER2-positive BC. Regarding treatment, 50% of patients were treated with curative intent, of whom 3 have no evidence of recurrence at a follow up of 23-137 months. Of the other two patients, one had response to systemic treatment but remains surgically unresectable and the other patient developed recurrent disease. In the 5 patients treated with palliative systemic therapy as Stage IV disease, 3 patients had clinical response to first line treatment with control of disease. One patient who passed away had triple negative disease. The last patient developed progression of disease and is on second line systemic treatment.
Conclusions: At our institution, among patients treated with palliative intent systemic therapy, most (60%) had a response to first line treatment. In the 5 patients treated with curative intent, 3 patients remain without evidence of recurrence of whom 2 have had 9 years of follow up. The current study illustrates the heterogeneity in management for patients with CAM. Our findings highlight the need for larger studies focusing on BC patients with CAM to optimize their treatment and outcomes. Limitations of our study include its retrospective nature and small sample size given rarity of CAM.
Table 1. Treatment and Outcomes of Patients with CAM
Citation Format: Rima Patel, Shana Berwick, Cao Jin, Paula Klein. Management of Isolated Contralateral Axillary Lymph Node Metastasis in Breast Cancer: A Single Institution Experience [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-59.