Abstract P3-01-19: Relationship of axillary total tumor load (TTL) by OSNA (one step nucleic acid amplification) in early breast cancer and clinical outcomes using strict Z0011 study criteria for axilla management

Abstract

Background: The study of sentinel lymph node (SNL) assessed by OSNA provides a new variable, Total Tumoral Load (TTL).This variable is defined as the amount of CK19 mRNA copies number in all positives SLN. TTL has been showed to predict the axillary node status and has been analysed to determine its usefulness in the axillary surgical management. Based on TTL values different cut-off points have been proposed (last 25.000 copies) to establish a new tool to practice axillary lymph node dissection (ALND). We present the follow-up data of at least 5 years of breast cancer patients who underwent ALND according, strictly, to Z0011 trial criteria. We hypothesized that there will be no correlation between TTL and locoregional relapse if Z0011 are followed. Methods: Clinicopathological and follow up data were obtained from patients with invasive breast cancer and SLN assessed by OSNA between 2011 and 2012 at Complejo Asistencial de Ávila, Spain. ALND was decided based on Z0011 study criteria independently of TTL. All patients have been followed for a minimun of 5 years. Results: A total of 106 patients underwent SN assessed by OSNA, age range 27-85 years (mean 58,96). Of them 90% were ductal, 7,5% lobular and 2% others. By inmunophenotype: Luminal A 55%, Luminal B 28%, Triple Negative 9,4%, Her2 positive 3,7% and Luminal B-Her2 positive 2,8%. TTL was equal to zero in 58 cases and greater than zero in 48 cases with a range of 280-2.700.000 copies. Only 5 cases met ALND criteria (average TTL 68.164). Average TTL in cases without ALND was 111.000. For the time being, none of them has had locoregional relapse (median follow up 65 months). 3 patients have died one metastatic desease (Negative SN), one uterine cervix cancer and one neutropenic fever. Baseline and outcomes dataVARIABLE N%Age, years (median, range) 59 (27-85) Tumour TypeDuctal9690,5 Lobular87,5 Others21,8InmunophenotypeLuminal A5955,6 Luminal B3028,3 Luminal B-Her232,8 Her243,7 Triple Negative109,4Total Tumoral Load (TTL)=05854,7 >04845,2Axillary Lymph Node Dissection (ALND) 254,7TTL >25.000 2321,7Locoregional relapse 00Overall Survival 95,2 Conclusions: -Using Z0011 criteria and OSNA no locoregional recurrence has been observed so far. -TTL did not predict risk of recurrence -If we had based axillary management only on TTL values (i.e higher than 25.000 copies) we would have unnecessarily increased the number of lymphadenectomies in a 22%. This is an ongoing study that designed to increased the sample size and obtain longer follow-up data. Citation Format: Tur R, De Grado C, Martin MR, De Castro J, Filipovich E, Segovia B, Ceballos J, Parra J, Revestido R, Alés-Martínez JE. Relationship of axillary total tumor load (TTL) by OSNA (one step nucleic acid amplification) in early breast cancer and clinical outcomes using strict Z0011 study criteria for axilla management [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-19.