Faculty, Staff and Student Publications

Publication Date

6-5-2023

Journal

Cancers

Abstract

Background: KRASG12C-mutated metastatic colorectal cancer (mCRC) has recently been recognized as a distinct druggable molecular entity; however, there are limited data on its sensitivity to standard chemotherapy. In the near future, the combination of chemotherapy plus a KRASG12C-inhibitor might become the standard of care; however, the optimal chemotherapy backbone is unknown.

Methods: A multicentre retrospective analysis was conducted including KRASG12C-mutated mCRC patients treated with first-line FOLFIRI or FOLFOX +/- bevacizumab. Both unmatched and propensity-score-matched analysis (PSMA) were conducted, with PSMA controlling for: previous adjuvant chemotherapy, ECOG PS, use of bevacizumab in first line, timing of metastasis appearance, time from diagnosis to first-line start, number of metastatic sites, presence of mucinous component, gender, and age. Subgroup analyses were also performed to investigate subgroup treatment-effect interactions. KRASG12D-mutated patients were analysed as control.

Results: One hundred and four patients treated with irinotecan-(N = 47) or oxaliplatin-based (N = 57) chemotherapy were included. In the unmatched population, objective response rate (ORR) and median (m) progression-free and overall survival (mPFS and mOS) were comparable between the treatment arms. However, a late (>12 months) PFS advantage was observed with irinotecan (HR 0.62, p = 0.02). In the PSMA-derived cohort, a significant improvement with irinotecan vs. oxaliplatin was observed for both PFS and OS: 12- and 24-month PFS rates of 55% vs. 31% and 40% vs. 0% (HR 0.40, p = 0.01) and mOS 37.9 vs. 21.7 months (HR 0.45, p = 0.045), respectively. According to the subgroup analysis, interaction effects between the presence of lung metastases and treatment groups were found in terms of PFS (p for interaction = 0.08) and OS (p for interaction = 0.03), with a higher benefit from irinotecan in patients without lung metastases. No difference between treatment groups was observed in the KRASG12D-mutated cohort (N = 153).

Conclusions: First-line irinotecan-based regimens provided better survival results in KRASG12C-mutated mCRC patients and should be preferred over oxaliplatin. These findings should also be considered when investigating chemotherapy plus targeted agent combinations.

Keywords

KRASG12C mutation, irinotecan, metastatic colorectal cancer, oxaliplatin

DOI

10.3390/cancers15113064

PMID

37297026

PMCID

PMC10252545

PubMedCentral® Posted Date

6-5-2023

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

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