The Role of HER2 Testing in Advanced Colorectal Cancer

AbstractPurpose of ReviewAbout 1/3 of all metastatic colorectal cancer (mCRC) patients may harbor a mutation in theKRAS orNRAS gene suggesting inefficacy of EGFR inhibitors cetuximab and panitumumab. In spite of tailoring treatment inRAS wild-type patients to receive EGFR inhibitors, not all show response.Recent FindingsStudies have shown that HER2-neu amplification/alteration in addition to alteration inBRAF andPI3KA may explain resistance to EGFR inhibitors. Several pre-clinical studies have identified that HER2-neu amplification can result in both de novo and acquired resistance to EGFR inhibitors. Recently, several clinical studies have highlighted the use of single or combination HER2-neu directed therapies in HER2-neu amplified/overexpressed mCRC.SummaryAbout 5% mCRC patients will demonstrate HER2-neu overexpression and response to HER2-neu-directed therapies can be in the range of 30 –38%. Patients not responding to EGFR-inhibitors warrant testing for HER2-neu testing to explain resistance. In the near future, HER2-neu testing is likely to be integrated into our routine clinical practice for management of metastatic colorectal cancer patients.

Source: Current Colorectal Cancer Reports - October 29, 2018 Category: Cancer & Oncology Source Type: research