Reduced oxaliplatin exposure in gastrointestinal cancers: A systematic review and meta-analysis.

Abstract

3592 Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent dose-limiting toxicity from oxaliplatin that impairs quality of life in gastrointestinal (GI) cancer patients (pts). While strategies to limit exposure exist, their impact on survival remains debated. We evaluated whether reduced oxaliplatin exposure (ROE) maintains survival while mitigating toxicity. Methods: We conducted a systematic review and meta-analysis (PubMed, Embase, Scopus, Web of Science, EBM Reviews) of studies comparing ROE vs standard-duration oxaliplatin-based chemotherapy in GI cancers. ROE was defined as planned limitation of oxaliplatin exposure, including shortened duration (3-4 months), maintenance-based de-escalation, or stop-and-go strategies. Primary endpoints were disease-free survival (DFS) in curative settings, progression-free survival (PFS) in palliative settings, and overall survival (OS). Secondary endpoints included grade ≥3 CIPN and grade ≥3 adverse events (AEs). Random-effects models used Hartung-Knapp-Sidik-Jonkman correction. Heterogeneity was assessed via I² and Cochran’s Q. Results: 24 studies, comprising 15 randomized controlled trials (RCTs) and 9 retrospective cohorts, were included (N = 30,404 pts; ROE: 13,348; control: 17,056). Settings included adjuvant colorectal cancer (CRC; n = 14), metastatic CRC (mCRC; n = 5), gastric cancer (GC) (adjuvant n = 1, metastatic n = 3), and metastatic pancreatic cancer (PDAC) (n = 1). ROE strategies included shortened duration (n = 14), maintenance (n = 8), and stop-and-go (n = 2). In adjuvant CRC, ROE did not compromise DFS (HR 1.07; 95% CI, 0.98-1.16; p = 0.12; I² = 21.7%), including in high-risk subgroups (HR 1.14; 95% CI, 0.93-1.40; p = 0.14; I² = 38.9%); OS was also not different between groups (HR 1.00; 95% CI, 0.94-1.07; p = 0.89; I² = 0%), including high-risk pts (HR 1.01; 95% CI, 0.93-1.10; p = 0.68; I² = 0%). In mCRC, ROE showed no detriment to PFS (HR 1.11; 95% CI, 0.99-1.25; p = 0.07; I² = 0%) or OS (HR 1.06; 95% CI, 0.92-1.23; p = 0.33; I² = 0%). Similarly, in metastatic gastric cancer, PFS (HR 0.82; 95% CI, 0.34-1.99; p = 0.44; I² = 77.3%) and OS (HR 0.90; 95% CI, 0.67-1.21; p = 0.26; I² = 0%) were comparable. Findings remained concordant after restricting the analysis to only RCTs. Pooled analysis was not feasible for PDAC and adjuvant GC studies, but individual study findings were consistent with the above. ROE significantly reduced the risk of grade ≥3 CIPN (OR 0.32; 95% CI, 0.20-0.53; p < 0.001; I² = 80.6%) and overall grade ≥3 AEs (OR 0.65; 95% CI, 0.50-0.86; p = 0.01; I² = 59.9%). Conclusions: Across GI malignancies, ROE was not associated with inferior DFS, PFS, or OS and was associated with lower rates of severe neurotoxicity and high-grade AEs. These findings support planned limitation of oxaliplatin exposure as a strategy to improve the therapeutic index of oxaliplatin-based chemotherapy across disease settings.