Retrospective analysis of high intensity focused ultrasound combined with S-1 in the treatment of metastatic pancreatic cancer after failure of gemcitabine.

The purpose of this study was to verify the efficacy and safety of high intensity focused ultrasound therapy (HIFU) combined with S-1 in the treatment of metastatic pancreatic cancer after failure of gemcitabine (GEM). In total, 120 patients with GEM-refractory PC who received HIFU and S-1 between Aug 2012 and December 2014 were randomly assigned to 2 groups. The patients in group A (n = 61) received HIFU in combination with S-1 and those in group B (n = 59) were given S-1 alone. S-1 was administered orally twice a day on days 1-14. Cycles were repeated every 21 days. The follow up time was 3~19 months in both groups. The median overall survival (OS) time and progression free survival (PFS) were analysed by Kaplan-Meier method and Logrank test. The pain remission rate of the two groups was compared by χ(2) test. Patient characteristics and prognostic factors were compared. Patient characteristics did not significantly differ between the 2 groups. Median OS was significantly longer in group A (10.3 months) than in group B (6.6 months, P = 0.000). Median PFS was also significantly longer in group A than in group B (5.1 months vs 2.3 months, P = 0.000). Meanwhile, the pain remission rate was markedly higher in group A than in group B (57% vs. 20%, P = 0.000). There were mild side effects and no significant difference was observed between the two groups. The treatment effect was independently associated with a good outcome. HIFU in combination with S-1 might be effective and well tolerated as salvage chemotherapy in the treatment for metastatic pancreatic cancer.