Abstract P1-10-22: Predictive biomarkers of survival after neoadjuvant chemotherapy for breast cancer
Authors: Galvez-Nino Marco , Roque Katia , Bernabe Luis Angel , Castillo Miluska , Sanchez Joselyn , Baella Maria Landa , Calderon Gabriela , la Cruz Miguel De , Dunstan Jorge , Abugatas Julio , Cotrina Jose , Castaneda Carlos , Gomez Henry 
Published: March 2020

Introduction: The use of neoadjuvant chemotherapy (NAC) has become the standard of care in non-metastatic breast cancer patients meaning an improvement of tumor regression rates with a high impact on survival especially in patients who achieve pathological complete response (pCR). Predictive biomarkers of survival acquire more relevance in the setting of patients who don’t achieve complete response allowing us to design strategies based on the response evaluation. This study aimed to evaluate the predictive value of the NAC response represented by residual cancer burden (RCB) and tumor-infiltrating lymphocytes in residual disease (RD TILs). Methods: We analyze non-metastatic breast cancer patients diagnosed at Instituto Nacional de Enfermedades Neoplasicas (INEN), Lima-Peru who received NAC and were under surgery from 2016 to 2019, we performed a prospective evaluation of RCB and the level of stromal RD TILS by hematoxylin and eosin (H&E), CD-3 and CD-8 by immunohistochemistry in a subgroup of patients, we choose the median of percentage as a cut-off. Epidemiologic and clinic-pathological data were collected from clinical files. Survival analysis was calculated by using Kaplan-Meier method. Results: During the study period, we analyzed 271 NAC cases, median of age of diagnosis was 51 years, most common molecular subtype was Luminal B (56.5%) followed by Triple Negative (24.4%), 124 (45.8%) patients were at clinical stage IIIB followed by 54 (19.9%) IIB. 226 (83.4%) patients didn’t achieve pCR, most of them achieved RCB class III (40.6%) followed by RCB class II (37.6%). Among these we evaluated RD TILs in 42 patients. 54.8% of patients had RD TILs level greater than 30%, 53.3% had CD-3 level greater than 60% and 51.2% a level of CD-8 greater than 40%. Median PFS was 42 months (range 15.6 - 68) and estimated 3-years OS was 95.5%. We found significative difference between the RCB class and PFS (p=0.001) and OS (p=0.035), no differences between the level of stromal RD TILs, CD-3 or CD-8 with PFS or OS was found. Conclusion: Results from this cohort provide evidence for the benefit of NAC, in this setting RCB had a significative predictive value for breast cancer recurrence and survival, however, the level of RD TILs, CD-3 and CD-8 didn’t show differences on survival maybe by the number of cases. This work was supported by CONCYTEC (contract No. 198-2015-CONCYTEC) Keywords: Breast cancer, Neoadjuvant, Residual cancer burden, TILs, progression-free survival.

Citation Format: Marco Galvez-Nino, Katia Roque, Luis Angel Bernabe, Miluska Castillo, Joselyn Sanchez, Maria Landa Baella, Gabriela Calderon, Miguel De la Cruz, Jorge Dunstan, Julio Abugatas, Jose Cotrina, Carlos Castaneda, Henry Gomez. Predictive biomarkers of survival after neoadjuvant chemotherapy for breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-10-22.