AB094. P067. Therapeutic strategies and prognosis in patients with borderline resectable pancreatic adenocarcinoma: a multicenter retrospective study

Background: In order to increase the rate of curative resection and improve the prognosis for borderline resectable pancreatic adenocarcinoma (BR-PDAC), neoadjuvant therapy (NAT) has been adopted. However, sufficient evidence has not been established and therapeutic strategies for BR-PDAC differ from institution to institution. Multicentre retrospective study was performed to reveal the therapeutic strategies and outcome in patients with BR-PDAC.

Methods: Patients with BR-PDAC treated in 10 institutions from January 2010 to December 2014 were included in the present study. BR-PV involved the portal vein (PV) or superior mesenteric vein (SMV). BR-A involved the superior mesenteric artery, celiac axis, or hepatic artery.

Results: The present study included 176 patients (BR-PV, 106; BR-A, 70). NAT was performed in 69 patients (39.2%). The patient number of NAT plus resection, upfront surgery, and no resection group was 25, 104, and 47, respectively. NAT involved 29 of chemotherapy (42.0%) and 40 of chemoradiotherapy (58.0%). The overall median survival time (MST) of patients in NAT plus resection, upfront surgery, and no resection group was 53.7, 17.8, and 15.0 months, respectively. NAT plus resection was independent prognostic factor (HR =0.447, P=0.007). In patients who underwent surgical resection, there was no significant difference in clinical factors at initial diagnosis. However, the rates of the SMV/PV involvement and lymph node metastasis were significantly lower in NAT plus resection group compared upfront surgery group (P<0.001). In multivariate analysis in patients who underwent surgical resection, NAT (HR =0.535, P=0.044) and postoperative adjuvant therapy (HR =0.423, P<0.001) were independent prognostic factors.

Conclusions: In treatment for BR-PDAC, NAT may lead to downstage of the tumor and improvement the prognosis.