Comparison of Resected vs. Non-resected PanCO Study Patients with Unresectable Locally Advanced Pancreatic Cancer (uLAPC) Receiving 32P-microparticles and Chemotherapy.

Abstract

Introduction: uLAPC has poor prognosis. We report post-hoc analysis of resected vs. non-resected cohorts in a study of beta-radiation-emitting Phosphorous-32 (32P)-microparticles, implanted into tumours via endoscopic-ultrasound (EUS) guidance, and standard-of-care chemotherapy in uLAPC. Method(s): Eligible uLAPC, ECOG 0/1 patients received gemcitabine/nab-paclitaxel or FOLFIRINOX chemotherapy. 32P-microparticles (OncoSilTM) implantation was planned at weeks 4-5 to deliver 100Gy absorbed dose. Primary endpoint was safety/tolerability (CTCAE v4.0). Result(s): Fifty patients were enrolled (Intention-to-Treat); 40 received gemcitabine/nab-paclitaxel and 10 FOLFIRINOX; 42 were implanted with 32P-microparticles (Per Protocol [PP]) at median day 31. Median follow-up: 31.6 months. Ten participants (23.8% PP) underwent pancreaticoduodenectomy (median 4.4 months post-implant; 8/10 R0). Although baseline characteristics were similar (age; tumour longest diameter [LD]/volume), resected participants were more likely to be ECOG 0 (80% vs. 45%) and female (60% vs. 28%) vs. non-resected PP-cohort. Resected participants had greater tumour response as defined by median reductions at week 16 in tumour LD (-21.5% vs. -8.1%), tumour volume (-59.5% vs. -30.8%), CA 19-9 (-95.9% vs. -75.2%) and week 12 FDG-PET vs. non-resected PP-cohort. 39 AEs occurred <30 days post-resection with none attributed to 32P-microparticles/implantation. 180-day post-resection mortality was 0%. Resected participants median survival was not reached (95%CI: 21.1 months-non-calculable). Four resected participants survived 18.8-22.1 months post-enrolment; 6 remained alive at study completion (5 without recurrence) 26.4-35.3 months post-enrolment. Conclusion(s): EUS-guided 32P-microparticle implantation appears safe, with encouraging clinical outcomes and may convert uLAPC to surgical resection. Nearly one-quarter of PP participants (23.8%) underwent resection following substantial response with encouraging survival. Further studies are ongoing.Copyright © 2023