Integrating genomic mutations and tumor-infiltrating lymphocytes improves prediction of response to trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer.

ABSTRACT: Aim: Resistance to trastuzumab remains a major barrier to cure in early-stage HER2-positive breast cancer (HER2+ BC). We investigated the impact of genomic alterations and tumor-infiltrating lymphocyte (TIL) density on treatment resistance and survival outcomes. Methods: We retrospectively analyzed 315 patients with HER2+ BC who received adjuvant trastuzumab at Ruijin Hospital (2009-2019). Whole-exome sequencing and TIL scoring were performed on surgical specimens, and clinical and pathological data were collected. The Cancer Genome Atlas (TCGA) cohort was used for external validation. Genomic alterations and TIL density were compared between trastuzumab-sensitive and -resistant tumors. Survival analyses were conducted to identify prognostic biomarkers. Results: After

SUBMITTER: Lu S 

PROVIDER: S-EPMC12462396 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature