[Effect of pylorus-preserving pancreaticoduodenectomy on serum levels of 5-fluorouracil during S-1 treatment for pancreaticobiliary malignancy].

AIMS: The aim of this study was to evaluate the effect of surgical procedures on the serum levels of 5-fluorouracil (5-FU) in patients undergoing S-1 treatment for pancreaticobiliary malignancy.

METHODOLOGY: From January 2003 through December 2008, 27 chemotherapy-naive patients who underwent a surgical procedure for pancreaticobiliary malignancy received S-1 chemotherapy for unresectable or recurrent disease. The primary site of disease was: the extra hepatic bile duct (n=10); gallbladder (n=8); pancreas (n=6); or ampulla of Vater (n=3). The surgical procedure was: pylorus-preserving pancreaticoduodenectomy (PPPD) (n=6); combined major hepatic and bile duct resection (n=6); bilioenteric anastomosis (n=4); or exploratory laparotomy (n=11). S-1 (80-120 mg/day) was administered orally twice daily for 28 days, followed by 14 days without therapy. Subsequently, the serum levels of 5-FU were measured using the HPLC-UV method.

RESULTS

The median number of cycles administered per patient was 6 (range, 2-13). Although grade 3 watery eye developed in one patient, neither grade 4 toxicities nor treatment-related deaths were observed. The overall response rate was 19%, the median overall survival time was 9 months, and the 1-year cumulative survival rate was 11%. The maximum levels of 5-FU in the sera of individual patients differed significantly according to the surgical procedure (Kruskal-Wallis test; p=0. 0049); the patients who underwent PPPD had the highest 5-FU levels, as compared with the other patients (Mann-Whitney test; p= 0.003).

CONCLUSIONS

The type of operative procedure appears to influence the serum levels of 5-FU in S-1-treated surgical patients with pancreaticobiliary malignancy. Given the possibility of elevated levels of 5-FU in the sera of patients who are treated with S-1 after PPPD, adverse events must be monitored carefully in this cohort.