Abstract OT3-12-01: Immunological predictors of nodal response in breast cancer patients undergoing neoadjuvant therapy
Authors: Gasparri Maria Luisa , Ruscito Ilary , Bellati Filippo , Corsi Fabio , Micco Rosa Di , Gentilini Oreste Davide , Kuehn Thorsten , Papadia Andrea , Caserta Donatella , Rossi Lorenzo , Calcinotto Arianna 
Published: March 2023

Immunological predictors of nodal response in breast cancer patients undergoing neoadjuvant therapy Maria Luisa Gasparri1, Ilary Ruscito2, Filippo Bellati2, Fabio Corsi3, Rosa Di Micco4, Oreste D. Gentilini4, Thorsten Kuehn5, Andrea Papadia1, Donatella Caserta2, Lorenzo Rossi6, Arianna Calcinotto7 1 Department of Gynecology and Obstetrics, Ente Ospedaliero Cantonale, Ospedale Regionale di Lugano, Lugano, Switzerland 2 Department of Medical and Surgical Science and Translational Medicine, Sapienza University of Rome, Azienda Ospedaliera Sant’Andrea, Rome, Italy 3 Breast Unit, Department of Surgery, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy; Department of Biomedical and Clinical Sciences "Luigi Sacco", Università di Milano, Milan, Italy 4 Breast Surgery Unit, San Raffaele University Hospital, Milan, Italy 5 Interdisciplinary Breast Center, Department of Gynecology and Obstetrics, Klinikum Esslingen, Esslingen, Germany 6 Oncology Institute of Southern Switzerland, Bellinzona, Switzerland 7 Cancer Immunotherapy lab, IOR Institute of Oncology Research, Bellinzona, Switzerland Background: Almost 20% of breast cancer patients present at diagnosis with clinically positive nodes. Most of these patients undergo neoadjuvant therapy in order to de-escalate the axillary surgery in case of response (sentinel lymph node biopsy, targeted axillary dissection or targeted axillary dissection, instead of an axillary lymphadenectomy). The conversion from positive to negative nodes after neoadjuvant therpy is expected in approximately the 60% of the cases, depending by tumor subtypes. Several models have been proposed with the goal of identifying predictors of nodal response prior to neoadjuvant treatment. The immune system plays a pivotal role in cancer invasion and progression. Its role in treatment response is currently under investigation in several settings. Primary endpoint: to identify a preoperative immune profiling of breast cancer patients with nodal involvement at diagnosis and to correlate the immune changes after neoadjuvant therapy with the nodal response (macrometastases, micrometastasis, isolated tumor cells, complete response). Trial design: It is an international prospective cohort study including breast cancer patients undergoing standard neoadjuvant therapy, who present initially with biopsy-proven axillary lymph node metastasis. Ten immune markers will be analyzed using immunohistochemistry and tissue microarray in primary tumor and nodal tissue samples (tumor associated neutrophils, CD4 lymphocytes, CD8 lymphocytes, T regulatory cells, Macrophages, Follicular dendritic cells(DC), plasmocytoid DC, interdigitant DC, mature DC, Lysosomal associated membrane protein 3). The tissue analysis will be performed on the biopsy collected at diagnosis (prior to neoadjuvant therapy) and during the axillary surgery (after neoadjuvant therapy). Target accrual/sample size: 210 patients Statistical analysis: To compare the distribution of immune cells according to the state of lymph node metastasis, Student’s t test will be performed. Pearson’s chi-square test will be used to evaluate the correlation between immune profile and nodal response, based on clinic-pathological features. Odds ratios (ORs) and 95% confidence intervals (CIs) will be calculated using logistic regression analysis. Multivariable analysis will be performed using the multivariable logistic regression model. Logistic regression models will be used to identify the clinical, pathologic and immunological variables associated with the nodal response. P-values less than 0.05 will be considered significant. Analyses will be performed using Microsoft IBM SPSS® version 20.0 for Mac. Current status: Recruitment has not started yet. Contact information: marialuisa.gasparri@eoc.ch

Citation Format: Maria Luisa Gasparri, Ilary Ruscito, Filippo Bellati, Fabio Corsi, Rosa Di Micco, Oreste Davide Gentilini, Thorsten Kuehn, Andrea Papadia, Donatella Caserta, Lorenzo Rossi, Arianna Calcinotto. Immunological predictors of nodal response in breast cancer patients undergoing neoadjuvant therapy [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 OT3-12-01.