Effective management of 5-fluorouracil-induced coronary vasospasm allowing chemotherapy continuation: a single-center observational study

BACKGROUND: 5-fluorouracil (5-FU) is a widely used chemotherapy agent in gastrointestinal (GI) malignancies, but it can cause cardiotoxicity, most commonly manifesting as chest pain due to coronary vasospasm, often mimicking acute coronary syndrome. Adequate management of 5-FU-associated vasospasm is critical to ensure the necessary oncological treatment can be safely continued. OBJECTIVES: The aim of this study was the retrospective analysis of cases of chest pain associated with intravenous 5-FU treatment in GI cancer patients at a single institution, and to report the experiences with antianginal treatment, specifically nitrates and calcium channel blockers, administered in these cases. METHODS: This was a retrospective, single-center, observational cohort study. We analyzed data of GI cancer patients treated with intravenous 5-FU between March 2024 and August 2025 who experienced chest pain during treatment. Following the institutional protocol, the chemotherapy was transiently suspended, and treatment was re-introduced under combined oral or intravenous nitrate and calcium channel blocker protection. RESULTS: Out of 835 patients receiving iv 5-FU, 25 (2.9%) developed chest pain, typically after the second or third cycle of chemotherapy. Three patients presented with ST-elevation on ECG, but none of them showed significant coronary stenosis on imaging. With appropriate cardiological treatment, all 25 patients achieved symptom-free oncological treatment continuation: 19 patients with combined nitrate and calcium channel blocker therapy, 6 with monotherapy, and one of these patients required intravenous treatment under ICU monitoring. CONCLUSIONS: Coronary vasospasm associated with intravenous 5-FU is a rare but clinically significant complication. Our findings, in line with the literature, suggest that the introduction of antianginal therapy successfully allowed the safe rechallenge and continuation of oncological therapy in all affected patients, which may prevent unnecessary discontinuation of life-prolonging chemotherapy. TRIAL REGISTRATION: Retrospectively registered (Approval No. OOI/Ált11147-1/2025).