Effects of plasma concentrations of 5-fluorouracil on long-term survival after treatment with a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma

Background: a substantial body of literature has accumulated during the past 20 years showing the plasma concentrations of 5-fluorouracil (5-fu) to correlate with clinical response and/or toxicity in colorectal cancer,and head and neck cancer,but little information is available concerning effects on long-term survival. here,japanese patients with esophageal squamous cell carcinoma (escc) were followed up for 5 years after treatment with a definitive 5-fu/cisplatin (cddp)-based chemoradiotherapy (crt),and the association between prognosis and the plasma concentration of 5-fu was evaluated. methods. forty-nine patients with escc,who were treated with a definitive 5-fu/cddp-based crt,were enrolled. a course consisted of the continuous infusion of 5-fu at 400 mg/m2/day for days 1-5 and 8-12,the infusion of cddp at 40 mg/m2/day on days 1 and 8,and the 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. results: the overall 5-year survival rate was 42.9%. age (p = 0.020),body weight (p = 0.019),and disease stage (p = 0.048) affected the survival,and the survival depended on the clinical response assessed at 1 month after the treatment (p = 0.001). higher plasma concentrations of 5-fu resulted in a better clinical response (p = 0.043),and trended to prolong survival (p = 0.321). conclusions: the long-term survival after treatment with a definitive 5-fu/cddp-based crt possibly depends on the plasma concentrations of 5-fu,and further clinical studies with a larger number of cases are needed to clarify the relationship between them. © 2011 kuwahara et al; licensee biomed central ltd.