Axillary dissection 10 years after Z0011.

Abstract

e12582 Background: Axillary involvement is one of the strongest prognostic factors in breast cancer. Axillary lymphadenectomy (AL) has been considered one of the milestones to reduce relapse risk of local breast carcinoma. Z0011 trial, demonstrated that axillary dissection was not necessary in cases with one or two nodes involved. The authors proposed 3 sentinel nodes to decide if AL should be done. Since in the trials that explored the omission of lymphadenectomy obtained between one and six nodes, there is no consensus about how many lymph nodes should be obtained in the axillary sampling. The objective of this study is to obtain real data about axillary staging in real practice after Z0011 trial. Methods: 197 patients were selected from clinical records of Hospital Universitario de Torrejon. All patients were diagnosed with localized infiltrating breast carcinoma between 2016 and 2021. All were candidates for sentinel node biopsy (SNB) analyzed by OSNA or histopathology analysis. Patients with in situ tumors, those who underwent neoadjuvant chemotherapy We retrospectively reviewed the number of axillary nodes obtained in SNB and if axillary dissection was performed or not. Results: From 197 patients, 150 were included in the study (47 were excluded because were diagnosed with in situ carcinoma, received neoadjuvant chemotherapy or followup was lost). All 150 women were patients with infiltrating breast cancer who underwent conservative surgery or mastectomy and SNB. After surgical treatment, all patients received subsequent therapies indicated in each case (chemotherapy, radiotherapy or hormone therapy). Medium age at diagnosis was 57 years (range 30-87). Median number of sentinel nodes obtained in SNB was 2 (range 1 to 5). 40 patients had tumor infiltration in SNB, but only 15 underwent axillary dissection,10 of them had one node involved, 4 had 2 nodes involved and one had 3 nodes involved, from up to four extracted. 5 patients had more node involved than those found on the sentinel node biopsy, and all had macrometastasis. Capsular rupture was identified in 7 cases. None of the patients had relapse until the time of follow up was closed. Conclusions: Rate of axillary dissection after Z0011 has decreased without increasing risk of loco-regional or distant relapse. During the time of surgery, not always is possible to obtain 3 sentinel nodes, which could involve more aggressive surgery and comorbidities. Techniques of sentinel node identification are needed and further investigation to resolve in which cases axillary dissection is unavoidable.