Neoadjuvant chemotherapy with gemcitabine and S1 (GS) for pancreatic cancer planned resection

Abstract

Surgical resectability of pancreatic cancer (PC) was defined by the findings including general, oncological, and anatomical condition. Tumors without contact adjacent major vessels (Resectable) or only with port-mesenteric vein (BR-PV) are considered to be potentially R0-resectable PC (PC planned resection), and planned curative resection. Standard care for PC planned resection is Upfront-surgery (U-S) followed by adjuvant. Recent progress of post-operative chemotherapy has improved the survival of resected PC with recover after surgery, however, approximately half of the patients with PC planned resection could not receive the planned best practice (both curative surgery and adjuvant). Neoadjuvant chemotherapy (NAC) is a promising alternative for PC planned resection to maximize the population receiving best practice. PC patients with Resectable or borderline resectable (BR-PV) planned U-S or NAC with gemcitabine and S1 (NAC-GS) were reviewed by Intention-to-Treat analysis (ITT). From 2001 to 16, 336 eligible patients were treated by U-S or NAC-GS in our department. NAC-GS prolonged the survival, compared to U-S significantly (p=.028) by ITT. By subgroup analysis, BR-PV treated by NAC-GS showed a significant longer median survival (33.9 months, p=.0043) than U-S (21.0 months). NAC-GS improved the surrogate endpoint, significantly increased the population of normal tumor marker value after resection (p=.0007). The proportion of on-protocol cohort for NAC-GS was significantly higher than that for U-S (p=.022). PREP-02/JSAP05 (UMIN9634) is a prospective randomized Phase-II/III trial to evaluate superiority in survival of NAC-GS against U-S in patients with resectable and BRPV PC. The enrollment was finished with 364 patients from 47 centers on January 2016. Phase-II revealed the non-inferiority of resection rate of NAC-GS against U-S. This study will determine the efficacy of NAC-GS in addition to surgery followed by post-operative adjuvant for PC planned resection.