Methods for selection of neoadjuvant treatment with chemotherapy for patients with hormone receptor-positive and HER2-negative with early breast cancer.

person Ariadna Gasol Cudos Hospital Universitari Arnau de Vilanova de Lleida, Lleida, spain, Spain info_outline Ariadna Gasol Cudos, Serafin Morales Murillo, Noemí Tuset Der-abrain, Laura Arbones Cid, Ester Morera Morillo, Felip Vilardell, Douglas Sanchez Guzman, Carles Canosa Morales, Jordi Melé Olivé

Authors person Ariadna Gasol Cudos Hospital Universitari Arnau de Vilanova de Lleida, Lleida, spain, Spain info_outline Ariadna Gasol Cudos, Serafin Morales Murillo, Noemí Tuset Der-abrain, Laura Arbones Cid, Ester Morera Morillo, Felip Vilardell, Douglas Sanchez Guzman, Carles Canosa Morales, Jordi Melé Olivé Organizations Hospital Universitari Arnau de Vilanova de Lleida, Lleida, spain, Spain, Hospital Universitario Arnau de Vilanova. GEICAM Spanish Breast Cancer Group, Lleida, Spain, University Hospital Arnau de Vilanova, Lleida, Spain, hospital arnau de vilanova de lleida, Lleida, spain, Spain, hospital arnau de vilanova de lleida, Lleida, Spain, Spain, University Hospital Arnau de Vilanova, Lérida, Spain, University Hospital Arnau De Vilanova, Lleida, Spain Abstract Disclosures Research Funding No funding received None. Background: Neoadjuvant chemotherapy (NCT) in hormone receptor positive and HER2 negative early breast cancer used to achieve a poor pathological response although patients with residual tumor inferior to 10 mm had a better significant survival. Methods: We analyzed the pathologic response (complete or major response if the residual tumor is inferior to 10 mm) in a consecutive series of 333 patients treated in our center considering clinicopathological classical variables, oncotype RS score, and non-response to previous sort course of hormonotherapy measured by the decrease in the Ki67 index. Results: Median age was of 51 years (24-87), median tumor size of 32mm (9-10) and 54% had nodal involvement. Pathologic complete response (pCR) was achieved in 16,5% and pathologic response according Symmans method type 0 and I in 33,6 %. Variables associated with pCR were initial tumor size < 30 mm (OR: 0,409; p: 0,004), progesterone receptor < 100 by histoscore (OR: 0,289; p: 0,00001) and Ki67 index > 30 (OR: 2,23; p: 0,008). When these 3 variables have been associated, the pCR increases by 45%. When use the ONCOTYPE RS score to select patients to NCT the pCR found was 23,5% that increases to 42% if the RS score was superior to 32 in a series of 136 patients. Considering the RCB pathologic response, RS>32 achieved a total of 73% of RCB 0-1 response. Finally, using the hormone non-response in patients with short course of hormonotherapy with non-decreases the Ki67 index, we found a 30% of pCR and 63% of RCB type 0-1 pathologic response. Conclusions: Selecting patients with early breast cancer with positive hormone receptors for neoadjuvant treatment with chemotherapy achieves a high response rate, going from 16% and reaching 40% in selected cases. The genomic platform and hormonal testing through Ki67 changes are very useful tools to select these patients. pCR RCB 0-1 SERIE Initial Size Nodal inv Global Sleceting Global Sleceting GLOBAL 36,4 mm 53,80% 16,50% 45,80% 33,60% 58% ONCOTYPE 25 mm 51% 23,50% 41,80% 62% 72,70% NON-RESPONSE KI 67 24 mm 40,80% 30% 63%