RT Journal Article SR Electronic T1 An Immunoassay Method for the Pharmacokinetics of 5-Fluorouracil in Patients with Gastric Cancer Administered Adjuvant Chemotherapy JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 5111 OP 5114 VO 32 IS 11 A1 HIDEO MATSUMOTO A1 MASAHARU HIGASHIDA A1 HISAKO KUBOTA A1 HARUAKI MURAKAMI A1 KOSUKE TSUTSUMI A1 HIROSHI NAKASHIMA A1 YASUO OKA A1 HIDEO OKUMURA A1 MASAFUMI NAKAMURA A1 TOSHIHIRO HIRAI YR 2012 UL http://ar.iiarjournals.org/content/32/11/5111.abstract AB Conventional gas chromatography-mass spectrometry (GC-MS) was compared with a new immunoassay method for measuring plasma (5-FU) concentrations in adjuvant chemotherapy with TS-1 for patients with gastric cancer. TS-1 was administered orally to patients after gastrectomy. Blood samples for pharmacokinetic analysis were collected on the seventh day of treatment. The mean area under the time concentration curve (AUC)0-8, half-life (t1/2), and maximum drug concentration (Cmax) obtained by the two methods were as follows: GC-MS, 847.9 μg/ml/hr, 2.76 h, and 186.6 ng/ml; and immunoassay, 1311.2 μg/ml/hr, 3.5 h, and 259.8 ng/ml. Significant correlations were observed for AUC0-8 (p=0.0001), Cmax (p=0.0007), and changes in the 5-FU concentration in blood over time (p=0.018) for the two methods. Compared with the conventional GC-MS method, the new immunoassay method provides similar results, but is simpler and results can be obtained earlier. This method will be useful for monitoring the 5-FU concentration in serum from patients with gastric cancer receiving TS-1.