Buzard B, Douglass L, Gustafson B, Buckley J, Roth M, Kujtan L, Bansal D. Response to osimertinib in a colorectal cancer patient with an EGFR T790M mutation: A case report. World J Gastrointest Oncol 2023; 15(10): 1829-1834 [PMID: 37969405 DOI: 10.4251/wjgo.v15.i10.1829]
Corresponding Author of This Article
Lara Kujtan, MD, Associate Professor, Department of Medical Oncology, University of Missouri - Kansas City, No. 2310 Holmes St, Kansas, MO 64108, United States. kujtanl@umsystem.edu
Research Domain of This Article
Oncology
Article-Type of This Article
Case Report
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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: http://creativecommons.org/licenses/by-nc/4.0/
World J Gastrointest Oncol. Oct 15, 2023; 15(10): 1829-1834 Published online Oct 15, 2023. doi: 10.4251/wjgo.v15.i10.1829
Response to osimertinib in a colorectal cancer patient with an EGFR T790M mutation: A case report
Blake Buzard, Lindsey Douglass, Beth Gustafson, Jennifer Buckley, Marc Roth, Lara Kujtan, Dhruv Bansal
Blake Buzard, Lindsey Douglass, Beth Gustafson, Jennifer Buckley, Marc Roth, Cancer Institute, St. Luke's Hospital, Kansas, MO 64111, United States
Lara Kujtan, Department of Medical Oncology, University of Missouri - Kansas City, Kansas, MO 64108, United States
Dhruv Bansal, Department of Hematology/Oncology, St. Luke's Cancer Institute, Kansas, MO 64111, United States
Author contributions: All authors contributed to manuscript writing; all authors have read and approved the final manuscript.
Informed consent statement: Consent for this publication was received from the patient’s legal guardian.
Conflict-of-interest statement: The authors declare no conflicts of interest.
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: Lara Kujtan, MD, Associate Professor, Department of Medical Oncology, University of Missouri - Kansas City, No. 2310 Holmes St, Kansas, MO 64108, United States. kujtanl@umsystem.edu
Received: July 21, 2023 Peer-review started: July 21, 2023 First decision: August 23, 2023 Revised: September 6, 2023 Accepted: September 18, 2023 Article in press: September 18, 2023 Published online: October 15, 2023 Processing time: 80 Days and 11.6 Hours
Abstract
BACKGROUND
Although common in lung cancer, somatic epidermal growth factor receptor (EGFR) mutations are rarely found in colorectal cancer, occurring in approximately 3% of cases. Treatment with anti-EGFR antibodies is commonplace, but EGFR tyrosine kinase inhibitors are not standard treatments in colorectal cancer. Here we report a case of sustained response to osimertinib in a colorectal cancer patient with an EGFR T790M mutation on cell-free DNA analysis.
CASE SUMMARY
A 72-year old woman with a past medical history of post-polio syndrome confined to a wheelchair, scoliosis and hypothyroidism presented with metastatic sigmoid colon adenocarcinoma with hepatic metastases. Next generation sequencing revealed a RAS/RAF wild-type, microsatellite stable, PD-L1 negative malignancy. Mutations in TP3 and APC were also identified, as well as EGFR amplification. Cell-free DNA analysis revealed an EGFR T790M mutation. She was unable to tolerate first-line treatment with panitumumab, 5-fluorouracil and leucovorin, progressed on second-line treatment with trifluridine/tipiracil plus bevacizumab, and was unable to tolerate third-line treatment with regorafenib. She was started on fourth-line treatment with off-label osimertinib, with clinical response – decrease in size of hepatic metastases and a pericardial effusion. She remained on treatment with osimertinib for seven months.
CONCLUSION
This case shows the benefit of multi-gene sequencing assays to identify potential therapeutic options in patients with refractory disease.
Core Tip: Somatic epidermal growth factor receptor (EGFR) mutations are rarely found in colorectal cancer. Treatment with anti-EGFR antibodies is commonplace, but EGFR tyrosine kinase inhibitors are not standard in colorectal cancer. Here we report a case of sustained response to osimertinib in a metastatic colorectal cancer patient with an EGFR T790M mutation detected with cell-free DNA. She progressed on three lines of treatment, and received fourth-line treatment with off-label osimertinib, with clinical response. She received treatment with osimertinib for seven months. This case shows the benefit of multi-gene sequencing assays to identify potential therapeutic options in patients with refractory disease.
