Bolus 5-fluorouracil as an alternative in patients with cardiotoxicity associated with infusion 5-fluorouracil and capecitabine: a case series.

BACKGROUND 5-Fluorouracil (5-FU) is the backbone of chemotherapy regimens approved for treatment of colorectal cancer. The incidence of cardiotoxicity associated with 5-FU ranges from 1.5% to 18%; 48% as anginal symptoms and 2% as cardiogenic shock. Cardiotoxicity is unpredictable and no alternative chemotherapeutics have been defined so far. PATIENTS AND METHODS We present a case series of six patients who developed cardiotoxicity on infusional fluorouracil and/or capecitabine and were challenged with bolus 5-FU for the treatment of their malignancies. Four patients were tested for polymorphic abnormality of the human dihydropyrimidine dehydrogenase gene (DPYD) with the TheraGuide 5-FU™ (Myriad Genetic Laboratories, Inc., Salt Lake City, UT, USA) pharmacogenetic test. RESULTS Five patients were challenged with oral capecitabine that reproduced clinical and/or diagnostic concerns. All six patients tolerated bolus 5-FU either as a radiosensitizing agent or as chemotherapy without recurrence of a cardiac insult. DPYD was normal in the four patients tested. CONCLUSION Cardiotoxicity induced by 5-FU seems to be schedule-dependent. Bolus 5-FU can be used in patients developing cardiotoxicity due to 5-FU infusion or capecitabine with vigilance.