Effects of S-1 and Capecitabine on Coronary Artery Blood Flow

Fluoropyrimidine chemotherapy agents , such as 5-fluorouracil and capecitabine, are occasionally associated with cardiac toxicity. Clinical fluoropyrimidine cardiotoxicity is infrequent, but subclinical toxicity may be much more common. Cardiac toxicity may be less frequent with S-1 as compared with 5-fluorouracil and capecitabine, but head-to-head comparisons are lacking. The purpose of the study is to compare 2 measures of subclinical coronary artery microvascular dysfunction, the coronary flow reserve and the coronary flow response to a cold pressor test, in a patient population who are being treated for adenocarcinoma of the gastrointestinal tract with one of 2 oxaliplatin-containing regimens, either with oxaliplatin plus S-1 or with oxaliplatin plus capecitabine.