5-Fluorouracil Rechallenge After Cardiotoxicity.

Area of Science:

• Oncology
• Cardiology
• Pharmacology

Background:

• 5-Fluorouracil (5-FU) is a cornerstone chemotherapy for solid tumors.
• 5-FU-induced cardiotoxicity presents a significant clinical challenge, ranging from angina to sudden cardiac death.
• Rechallenging patients with 5-FU after a major cardiac event is often debated due to potential risks.

Observation:

• A stage III colorectal adenocarcinoma patient experienced ventricular fibrillation during FOLFOX chemotherapy.
• Cardiac workup identified probable 5-FU-induced vasospasm as the cause, with no obstructive coronary artery disease.
• After initial 5-FU cessation and disease progression, the patient was rechallenged with 5-FU/leucovorin under prophylactic antianginal therapy.

Findings:

• The patient tolerated 5-FU rechallenge without recurrent cardiovascular complications.
• Prophylactic use of isosorbide dinitrate, diltiazem, and metoprolol, along with bolus dosing and telemetry monitoring, facilitated safe rechallenge.
• Screening for dihydropyrimidine dehydrogenase deficiency may aid in personalized 5-FU dosing and safety strategies.

Implications:

• This case suggests that 5-FU rechallenge is feasible in select patients with prior cardiotoxicity.
• A multidisciplinary approach, prophylactic antianginal therapy, and continuous monitoring are crucial for managing 5-FU cardiotoxicity.
• Individualized strategies, potentially including genetic screening, can optimize 5-FU therapy safety and efficacy.