Abstract P5-15-02: Characteristics and Prognosis of Patients Presenting with Isolated Axillary Nodal Metastases from Occult Breast Primary Carcinoma

Abstract

Abstract Background: Patients presenting with isolated axillary metastatic carcinoma represent a potentially curable subset of patients. As there are no published randomized trials, literature concerning this uncommon clinical entity is limited to small retrospective reports. These vary widely with respect to the information collected, span a large time period during which diagnostic and therapeutic options have advanced considerably, and are largely without a contemporary control group. Methods: The British Columbia Breast Cancer Outcomes Unit (BCOU) database was searched to identify patients referred to the British Columbia Cancer Agency with a new diagnosis of isolated axillary metastatic cancer diagnosed between 2000 and 2005. Eligible patients were female, had pathological evidence of lymph node (LN) involvement but no evidence of a primary tumor or distant metastases on clinical workup. A series of control patients, with pathological T1 tumors and N1 involvement at presentation were selected from the BCOU database matched 3:1 for age, diagnosis year, tumor characteristics (histology, estrogen receptor status, HER2 status, and number of affected lymph nodes), and systemic treatment characteristics (adjuvant chemotherapy and/or endocrine therapy). Results: 36 patients were identified to form the primary axillary cohort. The controls consisted of 1,406 patients, of whom 106 were matched for the above characteristics. Patients in the primary axillary cohort were fairly well-distributed among all diagnosis years, and all tumors exhibited ductal histology. 26 (72%) were estrogen receptor-positive and 8 (22%) were known to be HER2-positive. 9 (25%) patients underwent mastectomy. 33 (92%) patients received radiation therapy and 19 (53%) did not undergo any breast surgery. With a median follow-up of 5.2 and 5.4 years for the primary axillary cohort and the matched controls, the BCSS was 93% and 88% respectively. There were no locoregional recurrences documented in the primary axillary cohort. Conclusions: This study represents one of the larger contemporary case control series of isolated axillary nodal presentations, demonstrating a good prognosis for this cohort of patients despite approximately half of the patients not having primary breast surgery. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-15-02.