145P Prognostic value of tumor-infiltrating lymphocytes in HER2-positive breast cancer treated with neoadjuvant chemotherapy and dual HER2-blockade: A TRAIN-2 sub study

BackgroundPreviously, it has been demonstrated that stromal tumor-infiltrating lymphocytes (sTILs) provide independent prognostic information in early-stage HER2-positive breast cancer. The aim of our study was to validate these findings by studying sTILs and outcome measures cancer patients who were randomized receive neoadjuvant chemotherapy with or without anthracyclines plus trastuzumab pertuzumab the TRAIN-2 study.MethodsFollowing sTIL scoring on pre-treatment biopsies two pathologists, geometric mean calculated. When scores differed more than 10%, a final score assigned after revision one pathologist. association between pathological complete response (pCR) studied using logistic regression analyses adjusted for age, hormone receptor (HR) status, clinical T-stage, N-stage, tumor grade treatment arm. Similarly, relation event-free survival (EFS) evaluated Cox analyses.ResultsTable: 145PStromal TILs, 5-year ratesGroupNumber events5-year EFS (%)95% CILow sTILs, no pCR11/7383.875.3 - 93.2High pCR8/4581.771.0 94.1Low pCR13/12981.569.7 95.2High pCR3/12397.594.7 100 Open table new tab ConclusionsWe did not observe significant pCR adjustment variables. However, high show excellent rates compared low sTILs. Early-stage may be candidates de-escalated adjuvant treatment, whereas benefit additional treatment.Clinical trial identificationNCT01996267.Legal entity responsible studyBOOG Study Center.FundingRoche.DisclosureA.E. van Leeuwen-Stok: Financial Interests, Institutional, Funding, Roche funding study: . H. Horlings: Funding: Roche; Non-Financial Advisory Role: SlideScore.com. R.F. Salgado: Other: Merck , Bristol Myers Squibb; Puma Biotechnology, Personal, Board: Exact Sciences, Squibb G.S. Sonke: Novartis Agendia, AstraZeneca Seagen; Seagen, Biovica. All other authors have declared conflicts interest. study. Previously, MethodsFollowing analyses. Following ResultsTable: treatment. We