Efficacy of chemotherapy in patients with recurrent pancreatic cancer.

Abstract

466 Background: Gemcitabine (GEM) plus nab-paclitaxel (GnP) and FOLFIRINOX (FFX) are standard first-line chemotherapy regimens for metastatic pancreatic cancer (MPC) patients. GEM and S-1 are also used for these patients in Japan. However, the phase 3 trials included a small proportion of recurrent pancreatic cancer (RPC) patients, and patients who had received adjuvant chemotherapy were excluded. In clinical practice, RPC is treated in the same way as MPC. The aim of this study is to compare the efficacy of chemotherapy between RPC and MPC. Methods: We retrospectively analyzed the patients with RPC or MPC who received GnP, FFX, GEM, or S-1 as first-line chemotherapy between January 2014 and March 2016 in our institution. RPC was defined as pancreatic cancer with recurrence after R0 or R1 resection. Overall survival (OS), progression-free survival (PFS), response rate (RR), and disease control rate (DCR) were evaluated. Multivariate analyses of OS were performed with the use of a Cox proportional-hazard model. Results: A total of 181 patients, 40 RPC and 141 MPC, were selected in this study. RPC and MPC groups were similar with respect to age, sex, and performance status (PS). However, the RPC group had lower percentage of liver metastases (P < 0.001). The regimens were GnP/FFX/GEM/S-1: 10/3/20/7 in the RPC group and 37/34/67/3 in the MPC group, respectively. In the RPC group, 31 of 40 patients had received adjuvant chemotherapy; S-1/GEM: 24/7. The median OS was 16.6 months in the RPC group as compared with 9.7 months in the MPC group (hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.37–1.10, P = 0.11). The median PFS was 4.8 months in the RPC group and 4.4 months in the MPC group (HR 0.86, 95% CI 0.57–1.30, P = 0.47). The RR was 10% versus 14% (P = 0.79), the DCR was 50% versus 52% (P = 0.86), in the two groups, respectively. Multivariate analysis showed PS (HR 2.19, 95% CI 1.38–3.49) and liver metastases (HR 2.34, 95% CI 1.47–2.34) were independent predictors of OS. On the other hand, RPC or MPC was not found to be an independent prognostic factor (HR 1.19, 95% CI 0.67–2.13). Conclusions: It is suggested that chemotherapy in RPC may have similar efficacy compared to MPC. The relatively longer OS in the RPC group seems to associate with the lower percentage of liver metastases.