Early [18F]FDG PET/CT Response after a Single Dose of Anti-EGFR Therapy as a Predictive Biomarker for Treatment Benefit in Patients with Advanced Colorectal Cancer
Year: 2025
Type: article
Abstract: PURPOSE: Anti-EGFR mAb therapy improves the clinical outcome of patients with metastatic colorectal cancer (mCRC). This study assessed the predictive value of early [18F]fluorodeoxyglucose ([18F]FDG) PET/CT after one anti-EGFR mAb treatment in patients with mCRC. PATIENTS AND METHODS: The multicenter IMPACT-CRC study (NCT02117466) prospectively included patients with mCRC receiving second- or third-line anti-EGFR mAb monotherapy. Clinical benefit (complete/partial response or stable disease per RECIST version 1.1) was determined with CT at 8 weeks. [18F]FDG PET/CT scans were performed at baseline and before the second treatment cycle (2 weeks). Total lesion glycolysis (TLG) change was evaluated as a predictive biomarker for clinical benefit using a predetermined data-driven threshold. RESULTS: In patients with RAS/BRAF wild-type left-sided mCRC, the clinical benefit rate was 92% (31% partial response, 61% stable disease), with a median progression-free survival of 5.7 months (95% CI, 5.2-10). Seventy-five patients, including those with right-sided mCRC, were eligible for metabolic response analysis. Patients with clinical benefit (n = 57) showed a mean decrease in sum TLG of 58% (SD = 19%), compared with 1.9% (SD = 36%) in those without clinical benefit (n = 18; P = 0.003). A threshold of <15% reduction in sum TLG had a 100% negative predictive value for clinical benefit. Metabolic responders exhibited longer progression-free survival than nonresponders [6.5 vs. 1.7 months (P < 0.001)]. CONCLUSIONS: Selecting patients with left-sided RAS/BRAF wild-type mCRC resulted in a 92% clinical benefit rate from anti-EGFR mAb monotherapy. Early [18F]FDG PET/CT identified nonresponders with 100% accuracy, offering promising clinical utility when tumor mutational status is unavailable.
Source: Clinical Cancer Research
Authors: Sophie L. Gerritse, Erik J. van Helden, Anne I.J. Arens, Ronald Boellaard, Tineke E. Buffart, Mariette Labots, Lindsay Angus, Elisabeth G.E. de Vries, Derk Jan A. de Groot, Hans F.M. Pruijt, Rutger H.T. Koornstra, Otto S. Hoekstra, Gerben J.C. Zwezerijnen, Elske C. Gootjes, Henk M.W. Verheul, C. Willemien Menke-van der Houven van Oordt
Institutions: Radboud University Nijmegen, Radboud University Medical Center, Reinier de Graaf Hospital, Radboud Institute for Health Sciences, Erasmus MC, Erasmus University Rotterdam, Amsterdam University Medical Centers, Cancer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC Location Vrije Universiteit Amsterdam, Erasmus MC Cancer Institute, University Medical Center Groningen, University of Groningen, Jeroen Bosch Ziekenhuis, Rijnstate Hospital
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W4416084514