Abstract B54: The clinical impact and analysis for neoadjuvant chemotherapy against borderline resectable pancreatic cancer: Gemcitabine plus S-1 vs. gemcitabine plus nab-paclitaxel

Abstract

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) shows a highly invasive and metastatic potential. Curative resection with multidisciplinary therapy is crucial for PDAC patients to improve the prognosis. It is also important to determine suitable regimen of neoadjuvant therapy (NAT) for locally advanced PDAC patients. Materials and Methods: In this study, 104 consecutive patients with BR PDAC who underwent pancreatectomy at Chiba University Hospital from Jan. 2008 to Dec. 2017 were retrospectively analyzed. We assessed the clinical significance of NAT compared to Surgery First (SF) in patients with borderline resectable (BR) PDAC. Furthermore, we compared the clinical impact between gemcitabine plus S-1 (GS) and gemcitabine plus nab-paclitaxel (GnP) for neoadjuvant chemotherapy (NAC) in BR PDAC. Results: In 84 BR head-PDAC and 20 BR body/tail-PDAC patients, 47 head-PDAC (56%) and 17 body/tail-PDAC (85%) were administered NAT, respectively. Comparing between SF and NAT group in each category, no significant differences were observed in the major clinicopathologic factors such as sex, operation time, blood volume loss, UICC-T, N factors, stage, or surgical curability. Median survival time (MST) for overall survival was 22.2 months for SF group and 23.1 months for NAT group in head-PDAC (p=0.08, log-rank), and not reached for SF group and 43.3 months for NAT group in body/tail-PDAC. Next, focusing on the differences of each strategy for NAC, we compared the clinical outcomes of patients between GS group (n=26) and GnP group (n=14) in head-PDAC and GS group (n=10) and GnP group (n=5) in body/tail-PDAC, respectively. The mean of NAC duration was 3.2 months for GS group and 2.7 months for GnP group. Among the clinicopathologic parameters, no differences of backgrounds for patients were observed between these two regimens. The response rates for RECIST criteria were 33.3% for GS group and 47.4% for GnP group in head-PDAC, notably 20% for GS group and 100% for GnP group in body/tail PDAC (p=0.001). The decrease rate of CA19-9 during NAC were 52.4% for GS group and 67.7% for GnP group (p=0.07). The Kaplan-Meier analysis revealed that the median survival time (MST) for disease-free survival after surgery was 9.7 months for GS group and 8.9 months for GnP group in head-PDAC, and 18.2 months for GS group and 14.7 months for GnP group in body/tail-PDAC. The MST for overall survival was 29.2 months for GS group and 24.7 months for GnP group in all BR PDAC. Conclusion: NAT (NAC) is a promising option in the treatment for patients with BR PDAC. Randomized prospective studies will be warranted for the strategy of treatment for patients with BR PDAC. Citation Format: Shigetsugu Takano, Hideyuki Yoshitomi, Shingo Kagawa, Katsunori Furukawa, Tsukasa Takayashiki, Satoshi Kuboki, Daisuke Suzuki, Nozomu Sakai, Takashi Mishima, Eri Nakadai, Masayuki Ohtsuka. The clinical impact and analysis for neoadjuvant chemotherapy against borderline resectable pancreatic cancer: Gemcitabine plus S-1 vs. gemcitabine plus nab-paclitaxel [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B54.