Efficacy and safety of omitting 5-fluorouracil bolus in combination chemotherapy regimens for gastrointestinal cancers: a systematic review and meta-analysis

This meta-analysis aimed to evaluate the impact of omitting the 5-FU bolus in chemotherapy regimens for gastrointestinal cancers on treatment efficacy and toxicity. We searched major databases and congress proceedings until 25 October 2024 to identify studies comparing 5-FU bolus and non-5-FU bolus regimens in patients with gastrointestinal cancers. The studies included those reporting on progression-free survival (PFS), overall survival (OS), and adverse events in metastatic gastrointestinal cancer patients. The analysis included 7 studies with 12,698 patients. No significant differences in PFS (HR: 0.94, 95% CI: 0.83–1.07) or OS (HR: 0.96, 95% CI: 0.89–1.03) were found between the 5-FU bolus and non-bolus groups. However, significantly higher rates of grade 3–4 neutropenia (OR: 0.46, 95% CI: 0.37–0.57) and any grade thrombocytopenia (OR: 0.53, 95% CI: 0.35–0.80) were observed in the 5-FU bolus group. No significant differences were found for other toxicities like febrile neutropenia, diarrhea, or nausea. This meta-analysis demonstrates that the omission of 5-FU bolus from the commonly used 5-FU-based chemotherapy regimens in gastrointestinal cancers, with the use of only 5-FU infusion, may reduce the risk of hematologic toxicities such as neutropenia and thrombocytopenia without affecting survival outcomes in metastatic gastrointestinal cancers. www.crd.york.ac.uk/prospero identifier is CRD42024602968.