Abstract P2-01-04: Use of axillary ultrasound impacts outcome of node positive breast cancer patients

Abstract

Abstract Background The Z0011 trial initiated a paradigm shift in the treatment of axillary node positive breast cancer patients. Treatment strategy, however, starts with the information gathered by the diagnostic axillary work up. This can either be done by sentinel lymph node biopsy (SLNB) or ultrasound guided lymph node biopsy (UGLNB). We examined whether there are relevant clinical and prognostic differences between patients found node positive by these two diagnostic selection processes. Methods Patients diagnosed with invasive breast cancer in the Netherlands between January 2000 and December 2013 were studied. Patients with no clinically palpable lymphadenopathy (cN0) and node-positive disease after an axillary lymph node dissection (ALND) were included. Patients with stage IV breast cancer, with clinical stage T3-T4 breast tumor according to the TNM-classification, those treated within the neo-adjuvant setting, patients with palpable axillary nodes (cN≥1) and patients who did not undergo an ALND were excluded. Results A total of 14,730 patients fulfilled the inclusion criteria, of whom 9,448 were included in the SLNB group and 5,282 in the UGLNB group. Patients in the UGLNB group were older at diagnosis (p<0.001), had larger tumors (p<0.001), a higher tumor grade (p=0.001), and were more likely to have a negative hormonal receptor status (p<0.001) and to undergo a mastectomy (p<0.001). Patients in the UGLNB group were also more likely to have ≥3 positive axillary lymph nodes (p<0.001) and, after adjustment for these differences, had a worseoverall survival (HR=1.64; 95% CI=1.53-1.75) compared to the node-positive patients in the SLNB group. Conclusion Our multicenter study shows that patients with a positive UGLNB have less favorable disease characteristics and a worse prognosis compared to patients with a positive SLNB. The diagnostic selection process plays an important role when axillary treatment strategies are considered. Therefore, we conclude that the conclusions of the Z0011 trial cannot (yet) be applied to patients with a positive UGLNB. Citation Format: Verheuvel NC, Voogd AC, Tjan-Heijnen VCG, Roumen RMH. Use of axillary ultrasound impacts outcome of node positive breast cancer patients [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 P2-01-04.