Ontology highlight
ABSTRACT: Purpose
To investigate circulating tumor DNA (ctDNA) RAS mutant (MT) incidence before salvage-line treatment and the clinicopathological features and molecular biological factors associated with the efficacy of anti-epithelial growth factor receptor (EGFR) monoclonal antibody (mAb) rechallenge for tissue RAS/BRAF wild type (WT) metastatic colorectal cancer (mCRC).Methods
This multi-institutional retrospective observational study included 74 patients with mCRC with tissue RAS/BRAF WT refractory to first-line chemotherapy containing anti-EGFR mAb. ctDNA RAS status was assessed using the OncoBEAM™ RAS CRC Kit. We explored the clinicopathological features associated with ctDNA RAS status and the factors related to anti-EGFR mAb rechallenge efficacy in multivariate Cox proportional hazard regression.Results
The incidence of RAS MT in ctDNA was 40.5% (30/74), which was associated with primary tumor resection (P = 0.016), liver metastasis (P < 0.001), and high tumor marker levels (P < 0.001). Among the 39 patients treated with anti-EGFR mAb rechallenge, those with ctDNA RAS WT showed significantly longer progression-free survival (PFS) than those with ctDNA RAS MT (median 4.1 vs. 2.7 months, hazard ratio [HR] = 0.39, P = 0.045). Patients who responded to first-line anti-EGFR mAb showed significantly longer PFS (HR = 0.21, P = 0.0026) and overall survival (OS) (HR = 0.23, P = 0.026) than those with stable disease.Conclusions
The incidence of ctDNA RAS MT mCRC was 40.5%, which was associated with liver metastases and high tumor volumes. Anti-EGFR mAb rechallenge may be effective for patients with mCRC who responded to first-line chemotherapy containing anti-EGFR mAb. No patients with RAS MT in ctDNA responded to anti-EGFR mAb rechallenge.
SUBMITTER: Fukuda K
PROVIDER: S-EPMC11283376 | biostudies-literature | 2024 Jul
REPOSITORIES: biostudies-literature
Fukuda Koshiro K Osumi Hiroki H Yoshinami Yuri Y Ooki Akira A Takashima Atsuo A Wakatsuki Takeru T Hirano Hidekazu H Nakayama Izuma I Ouchi Kota K Sawada Ryoichi R Fukuoka Shota S Ogura Mariko M Takahari Daisuke D Chin Keisho K Shoji Hirokazu H Okita Natsuko N Kato Ken K Ishizuka Naoki N Boku Narikazu N Yamaguchi Kensei K Shinozaki Eiji E
Journal of cancer research and clinical oncology 20240727 7
<h4>Purpose</h4>To investigate circulating tumor DNA (ctDNA) RAS mutant (MT) incidence before salvage-line treatment and the clinicopathological features and molecular biological factors associated with the efficacy of anti-epithelial growth factor receptor (EGFR) monoclonal antibody (mAb) rechallenge for tissue RAS/BRAF wild type (WT) metastatic colorectal cancer (mCRC).<h4>Methods</h4>This multi-institutional retrospective observational study included 74 patients with mCRC with tissue RAS/BRAF ...[more]