The Survival Benefit of Chemoradiotherapy following Induction Chemotherapy with Gemcitabine Plus Nab-Paclitaxel for Unresectable Locally Advanced Pancreatic Cancer

SIMPLE SUMMARY: An optimal therapeutic strategy for unresectable locally advanced pancreatic cancer (UR-LAPC) has not been established. The aim of this retrospective study was to evaluate the therapeutic efficacy, progression-free survival (PFS), and overall survival (OS) of patients with UR-LAPC who underwent gemcitabine plus nab-paclitaxel (GnP) as first-line chemotherapy followed by chemoradiotherapy (CRT) compared to chemotherapy alone (CTx) at our department in a Japanese cancer referral center between February 2015 and July 2018. CRT resulted in significantly better PFS and OS than CTx. In the multivariate analyses, CRT following induction chemotherapy was identified as an independent prognostic factor for OS. In summary, patients with UR-LAPC experienced favorable treatment outcomes after receiving GnP as the first-line chemotherapy, especially when receiving additional CRT after tailored courses of induction chemotherapy. Thus, this treatment strategy represents a promising treatment option for selected patients with UR-LAPC. ABSTRACT: An optimal therapeutic strategy for unresectable locally advanced pancreatic cancer (UR-LAPC) has not been established. This study investigated the therapeutic efficacy of chemoradiotherapy (CRT) following induction chemotherapy with gemcitabine plus nab-paclitaxel (GnP) (CRT group) compared with systemic chemotherapy alone (CTx group) in patients with UR-LAPC. This was a retrospective study of 63 consecutive patients with UR-LAPC treated at our department in a Japanese cancer referral center between February 2015 and July 2018. We excluded patients who underwent other regimens and those enrolled in another prospective study. The CRT group (n = 25) exhibited significantly better progression-free survival (PFS) and overall survival (OS) than the CTx group (n = 20, PFS 17.9 vs. 7.6 months, p = 0.044; OS 29.2 vs. 17.4 months, p < 0.001). In the multivariate analyses, CRT following induction chemotherapy was identified as an independent prognostic factor for OS. Seven (15.6%) patients underwent conversion surgery, all of whom were in the CRT group. The R0 resection rate was 85.7% (6/7). In summary, patients with UR-LAPC experienced favorable treatment outcomes after receiving GnP as the first-line chemotherapy, especially when receiving additional CRT. Thus, this treatment strategy represents a promising treatment option for selected patients with UR-LAPC.