Effect of dose-escalation of 5-fluorouracil on circadian variability of its pharmacokinetics in Japanese patients with Stage III/IVa esophageal squamous cell carcinoma.
OBJECTIVE
The effects of dose-escalation of 5-fluorouracil (5-FU) on the clinical outcome and pharmacokinetics of 5-FU were investigated in Japanese patients with Stage III/IVa esophageal squamous cell carcinoma.


METHODS
Thirty-five patients with Stage III/IVa were enrolled, who were treated with a definitive 5-FU/cisplatin-based chemoradiotherapy. A course consisted of continuous infusion of 5-FU at 400 mg/m(2)/day (the standard dose group, N=27) or 500-550 mg/m(2)/day (the high dose group, N=8) for days 1-5 and 8-12, infusion of cisplatin at 40 mg/m(2)/day on days 1 and 8, and radiation at 2 Gy/day on days 1 to 5, 8 to 12, and 15 to 19, with a second course repeated after a 2-week interval. Plasma concentrations of 5-FU were determined by high performance liquid chromatography at 5:00 PM on days 3, 10, 38 and 45, and at 5:00 AM on days 4, 11, 39 and 46.


CONCLUSIONS
No patient with Stage IVa achieved a complete response in the standard dose group, whereas a complete response was observed at a rate of 50% in the high dose group, and this can be explained by a higher plasma concentration of 5-FU. The circadian rhythm in the concentrations found at the standard dose was not observed for a higher dose.
Kuwahara
Akiko
A
School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan.
Yamamori
Motohiro
M
Nishiguchi
Kohshi
K
Okuno
Tatsuya
T
Chayahara
Naoko
N
Miki
Ikuya
I
Tamura
Takao
T
Kadoyama
Kaori
K
Inokuma
Tsubasa
T
Takemoto
Yoshiji
Y
Nakamura
Tsutomu
T
Kataoka
Kazusaburo
K
Sakaeda
Toshiyuki
T
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics; D044466:Asian People; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009367:Neoplasm Staging; D016896:Treatment Outcome
D002945:Cisplatin; D005472:Fluorouracil