Anti-epidermal growth factor receptor treatment for patients with NeoRAS wild-type metastatic colorectal cancer: a case report of two cases

The NeoRAS phenomenon is defined as the conversion of tumor RAS status from mutant-type (MT) to wild-type (WT) after systemic chemotherapy in metastatic colorectal cancer (mCRC). Cetuximab, an anti-epidermal growth factor receptor (EGFR) antibody, is effective in patients with RAS WT mCRC but ineffe...

Full description

Saved in:
Bibliographic Details
Published in:Therapeutic advances in medical oncology 2023-01, Vol.15
Main Authors: Harada, Kazuaki, Yuki, Satoshi, Kawamoto, Yasuyuki, Nakamura, Takeaki, Kaneko, Shiho, Ishida, Koichi, Sakamoto, Naoya, Komatsu, Yoshito
Format: Article
Language:English
Subjects:
Ascites
Biopsy
Cancer therapies
Case Report
Chemotherapy
Colon cancer
Colorectal cancer
Colorectal carcinoma
Computed tomography
Epidermal growth factor
Epidermal growth factor receptors
Irinotecan
K-Ras protein
Liver
Metastases
Metastasis
Mutation
Patients
Point mutation
Tumors
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The NeoRAS phenomenon is defined as the conversion of tumor RAS status from mutant-type (MT) to wild-type (WT) after systemic chemotherapy in metastatic colorectal cancer (mCRC). Cetuximab, an anti-epidermal growth factor receptor (EGFR) antibody, is effective in patients with RAS WT mCRC but ineffective in those with RAS MT mCRC; however, its outcome in patients with NeoRAS WT mCRC is unclear. Herein, we report two cases of NeoRAS WT mCRC that responded clinically to anti-EGFR treatment. The first was a 40-year-old man with synchronous peritoneal metastatic rectosigmoid cancer. The first RAS testing on tumor tissue revealed a KRAS G12C mutation, which was converted to RAS WT after two lines of chemotherapy, as assessed by liquid biopsy. After initiating irinotecan plus cetuximab treatment, a computed tomography (CT) scan revealed that malignant ascites had resolved. The treatment was discontinued after 4 months because of disease progression. The second was a 68-year-old male patient with synchronous liver metastasis from sigmoid colon cancer. The KRAS G12D mutation, initially detected in tumor tissue, was not detected by liquid biopsy after six lines of chemotherapy. Cetuximab monotherapy was initiated, and the liver metastases shrank significantly. The patient continued cetuximab monotherapy for 8 months without disease progression. Our cases demonstrate the efficacy of anti-EGFR therapy for NeoRAS WT mCRC and highlight the importance of capturing the gene mutation profile throughout the clinical course for optimal treatment selection.
ISSN:1758-8359
1758-8340
1758-8359
DOI:10.1177/17588359231216090