The efficacy of addition of chemoradiotherapy to achieve resectability in locally-advanced pancreatic cancer remaining unresectable after neoadjuvant chemotherapy.

Abstract

e15761 Background: Although the efficacy of neoadjuvant chemotherapy (NACT) in achieving resectability in locally advanced pancreatic cancer (LAPC) has been 20-31%, many cases remain unresectable. The aim of this study is to evaluate the efficacy of adding chemo radiotherapy (CRT) to achieve resectability in LAPC that remained unresectable after NACT. Methods: Between January 2008 and December 2016, 38 patients with LAPC (borderline resectable or unresectable pancreatic cancer, BRPC or URPC) received NACT and remained unresectable; subsequently, all patients received CRT in an attempt to achieve resectability with curative-intent. The primary objective of this retrospective single institution study is to assess resection rate (RR) in these patients. The secondary objective is to assess overall survival (OS). Results: A total of 38 patients (22 male, 16 female) who were identified as BRPC (50%) or URPC (50%) at presentation as defined by multidisciplinary tumor board using pancreatic protocol CT scan received NACT and remained unresectable. The median age was 64 (56-70.5) years. The primary site was head of pancreas in 66% versus other sites in 34% . The T-stage distribution was T1 (2.6%), T2 (2.6%), T3 (34.2%) and T4 (60.6%). N0 and N1 were 63.1% and 36.9% respectively. The types of NACT included FOFIRINOX (39.5%), Gemcitabine-based (58%) and unknown (2.5%). The median number of NACT cycles was 4 (2.25-4). All patients received subsequent CRT. Only the primary tumor was targeted with a median dose of 5040 (4950-5400) cGy and a median number of fractions 18(18-28). Chemo used concurrently with radiation was 5-FU (52.5%), Xeloda (39.5%), Gemcitabine (5.5%) and unknown (2.5%). Of note, 36.8 % patients achieved resectablity (14/38). The R0 and R1 resections were 11 (28.9%) and 3 (7.9%) respectively. 52.6% patients received adjuvant chemotherapy. The OS was 17 (6-24) months in the R0 group versus 8 (7-9) months in the R1 group. For the whole group, median OS was 11.5 (7-18.25) months. Conclusions: The addition of CRT to NACT in LAPC may improve resectability leading to an OS that approximates the OS in those patients who had upfront resectable disease.