Case Report
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Sep 24, 2024; 15(9): 1232-1238
Published online Sep 24, 2024. doi: 10.5306/wjco.v15.i9.1232
Successful cetuximab rechallenge in metastatic colorectal cancer: A case report
Alexandra Guedes, Sandra Silva, Sandra Custódio, Andreia Capela
Alexandra Guedes, Sandra Silva, Sandra Custódio, Andreia Capela, Department of Medical Oncology, Centro Hospitalar Gaia/Espinho, Vila Nova de Gaia 4434-502, Portugal
Author contributions: Guedes A contributed to manuscript writing and editing, and data collection; Silva S contributed to data analysis; Capela A contributed to conceptualization and supervision; Custódio S was the patient’s attending physician. All authors have read and approved the final manuscript.
Informed consent statement: Informed written consent could not be obtained from the patient as he died in 2019.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Alexandra Guedes, MD, Doctor, Department of Medical Oncology, Centro Hospitalar Gaia/Espinho, Rua Conceição Fernandes S/N, Vila Nova de Gaia 4434-502, Portugal. alexandra.pereira.guedes@ulsge.min-saude.pt
Received: March 4, 2024
Revised: July 22, 2024
Accepted: August 15, 2024
Published online: September 24, 2024
Processing time: 177 Days and 21.7 Hours
Abstract
BACKGROUND

Metastatic colorectal cancer (mCRC) treatment has been evolving and increasingly driven by tumor biology and gene expression analysis. Rechallenge with epidermal growth factor receptor (EGFR) inhibitors (anti-EGFR) represents a promising strategy for patients with RAS wild-type (RAS-wt) mCRC and circulating tumor DNA has emerged as a potential selection strategy. Herein, we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge.

CASE SUMMARY

Our patient was diagnosed with stage IV RAS-wt, microsatellite-stable rectosigmoid junction adenocarcinoma. He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response, allowing for a left hepatectomy (R0), followed by post-operative chemotherapy and an anterior resection; progression-free survival (PFS) of 16 months was obtained. Due to hepatic and nodal relapse, second-line treatment with FOLFOX and bevacizumab was started with partial response; metastasectomy was performed (R0), achieving a PFS of 11 months. After a 15 months anti-EGFR-free interval, FOLFIRI and cetuximab were reintroduced upon disease progression, again with partial response and a PFS of 16 months. Following extensive hepatic relapse, cetuximab was reintroduced and a marked clinical and analytical improvement was seen, after only one cycle. RAS-wt status was confirmed on circulating tumor DNA. The patient’s overall survival exceeded 5 years.

CONCLUSION

Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.

Keywords: Metastatic colorectal cancer; RAS mutation; RAS wild type; Anti-epidermal growth factor receptor; Cetuximab; Rechallenge; Case report

Core Tip: In RAS-wild type patients treated with anti-epidermal growth factor receptor inhibitors, the emergence of RAS mutations leads to resistance to further anti-epidermal growth factor receptor treatment. However, resistant clones seem to decay over time upon treatment withdrawal. Liquid biopsy-driven cetuximab rechallenge can be effective in later lines of treatment of metastatic colorectal cancer. Longer anti-epidermal growth factor receptor-free intervals may act as a surrogate for improved responses and survival outcomes.