Evaluation of bolus and continued 5-fluorouracil infusion administration effects on arterial vasoconstruction

5-FU related cardiotoxicity is an infrequent side effect which can also be life threatening. The precise pathogenesis of 5-FU associated cardiotoxicity has not been clearly elucidated yet. Coronary vasospasm has historically been accepted to be the main contributor to this clinical entity. There are some studies inferring that bolus 5-FU administiration is more cardiotoxic than continued 5-FU infusion however there is no study comparing bolus and continued 5-FU administrations on vasoconstriction. Therefore, our aim in this study is to compare brachial artery diameters before and after 5-FU administrations in bolus and continued infusion groups. In our study, group 1 comprises of 33 patients receiving bolus 5-FU treatment and group 2 comprises of 32 patients receiving continued infusion 5-FU treatment. Breast cancer patients in group 1 receive FEC or FAC therapy, in group 2 patients with gastrointestinal system cancer receive FOLFOX ±monoclonal antibody (bevacizumab). Brachial artery diameter measurements performed immediately before and after the first 5-FU administration in both groups. For each patient serum albumin, calcium and haemoglobin levels checked and body mass index calculated according to height and weight measurements before the 5-FU administration. There is no statistically significant difference on brachial artery diameters between group 1 and 2 detected. Except gender and age, there is no variable in a relation with diameter difference revealed. Diameter difference is slightly significant detected in over 50 years old patients than under 50 years olds (p=0,056). It is also significant in male patients than females (p=0,041). Although patients with a history of cardiac disease are excluded, we believe that 5-FU's effect on vessel diameter changes by age. If the number of patients in the study is increased, significant differences can be detected. Fort his reason, we conclude there are more cardiotoxic effects due to vasoconstriction in 5-FU continued infusion administration. Key Words: 5-fluorourasil, vasoconstruction, toxicity