Case report: hand-foot syndrome induced by the oral fluoropyrimidine S-1.

Hand-foot syndrome (HFS) is a relatively common side effect of fluorouracil (5-FU) chemotherapy that has also been associated with the oral fluoropyrimidine capecitabine. Interestingly, HFS is virtually unknown to result from treatment with UFT, a combination of tegafur and uracil. Tegafur is a prodrug of 5-FU and is a component of S-1, another oral fluoropyrimidine active in a variety of solid tumors. We know of only one previously described case of S-1-induced HFS and the case reported here is the first to provide full documentation of this occurrence. The pathophysiology of chemotherapy-induced HFS remains unknown and very little pathological information is available. Treatment consists of topical emollient therapy, although pyridoxine has occasionally been beneficial. The study of HFS may provide an important insight into the pharmacology of fluoropyrimidines and allow for effective preventive strategies for this side effect of chemotherapy.