An Early-Onset Advanced Rectal Cancer Patient With Increased KRAS Gene Copy Number Showed A Primary Resistance to Cetuximab in Combination With Chemotherapy: A Case Report

• DOI: 10.3389/fonc.2021.755578
• Publication Date: 2021-11-30T12:19:55Z
• Authors: Tian Fang; Tingting Liang; Yizhuo Wang; Haitao Wu; Shuhan Liu; Linying Xie; Zhihao Zhang; Jiaying Liang; Cheng Yao; Yehui Tan; Chang Wang
• Keywords: FOLFIRI; Panitumumab

Mutations in KRAS (codon 12/13), NRAS, BRAFV600E, and amplification of ERBB2 MET account for 70-80% anti-epidermal growth factor receptor (EGFR) monoclonal antibody primary resistance. However, the list anti-EGFR resistance biomarkers is still incomplete. Herein, we report a case wild-type RAS/BRAF metastatic colorectal cancer (CRC) with to chemotherapy. Initially, mutation detection postoperative tumor tissue by using amplification-refractory system polymerase chain reaction indicated without point mutations, insertion deletions, or fusion mutations. Therefore, recommended combined therapy cetuximab FOLFIRI after failure platinum-based adjuvant chemotherapy, but disease continued progress. Next generation sequencing analysis revealed that copy number was increased detected SMAD4, RNF43, PREX2 This first advanced CRC numbers resistant which results poor patient survival, other mutated genes may be associated outcomes. Our findings indicate alterations should also examined, especially CRC, since it related these drugs.