학술논문

Genomics of ERBB2 -Positive Breast Cancer in Young Women Before and After Exposure to Chemotherapy Plus Trastuzumab.
Document Type
Article
Source
JCO Precision Oncology. 6/26/2023, Vol. 7, p1-10. 10p.
Subject
*BREAST cancer
*TRASTUZUMAB
*MYC oncogenes
*GENOMICS
*CANCER genes
Language
ISSN
2473-4284
Abstract
PURPOSE: Erb-B2 receptor tyrosine kinase 2 (ERBB2)–positive breast cancer (BC) is particularly common in young women. Genomic features of ERBB2 -positive tumors before and after chemotherapy and trastuzumab (chemo + H) have not been described in young women and are important for guiding study of therapeutic resistance in this population. METHODS: From a large prospective cohort of women age 40 years or younger with BC, we identified patients with ERBB2 -positive BC and tumor tissue available before and after chemo + H. Whole-exome sequencing (WES) was performed on each tumor and on germline DNA from blood. Tumor-normal pairs were analyzed for mutations and copy number (CN) changes. RESULTS: Twenty-two women had successful WES on samples from at least one time point; 12 of these had paired sequencing results from before and after chemo + H and 10 had successful sequencing from either time point. TP53 was the only significantly recurrently mutated gene in both pre- and post-treatment samples. MYC gene amplification was observed in four post-treatment tumors. Seven of 12 patients with paired samples showed acquired and/or clonally enriched alterations in cancer-related genes. One patient had an increased clonality putative activating mutation in ERBB2. Another patient acquired a clonal hotspot mutation in TP53. Other genomic changes acquired in post-treatment specimens included alterations in NOTCH2 , STIL , PIK3CA , and GATA3. There was no significant change in median ERBB2 CN (20.3 v 22.6; Wilcoxon P =.79) between paired samples. CONCLUSION: ERBB2 -positive BCs in young women displayed substantial genomic evolution after treatment with chemo + H. Approximately half of patients with paired samples demonstrated acquired and/or clonally enriched genomic changes in cancer genes. ERBB2 CN changes were uncommon. We identified several genes warranting exploration as potential mechanisms of resistance to therapy in this population. In young women with ERBB2+ BC, there was substantial genomic evolution on chemo + H—suggesting resistance pathways. [ABSTRACT FROM AUTHOR]