3553 POSTER Phase I/II study of S-1 in patients (pts) with advanced hepatocellular carcinoma (HCC): Results of phase I part – Correlation between pharmacokinetics (PK) and hepatic dysfunction

TS-1 is an oral fluoropyrimidine anticancer drug that contains tegafur, gimeracil, and oteracil. A 78-year-old Japanese male who was diagnosed with carcinoma of the oral floor (rT4aN0M0) was prescribed a standard dose of TS-1 (80 mg/day). On Day 8 after administration of TS-1, an eruption developed. There was erythema, along with vesicles and erosions involving the lip, face, neck, trunk, limbs, and genitals. The drug-induced lymphocyte stimulation test (DLST) for TS-1 was negative on the 23rd day, but positive on the 43rd day (20 days after discontinuing prednisolone). The condition was diagnosed as Stevens–Johnson syndrome due to TS-1 because of the clinical course and laboratory results. This case and 24 cases previously reported in the literature were analyzed. The types of drug eruption were drug-related lupus (9 cases), acral erythema (7 cases), scleroderma-like skin lesion (2 cases), Stevens–Johnson syndrome (2 cases), lichenoid eruption (1 case), purpura (1 case), lichen planus (1 case), erythema multiforme (1 case), hypopigmentation (1 case) and toxic epidermal necrolysis (1 case), respectively. In view of the increasing usage of TS-1 in several common cancers, clinicians should be aware of drug eruptions due to TS-1.