Carbon Ion Radiotherapy Versus Perioperative Adjuvant Chemotherapy and Curative Surgery for Resectable Pancreatic Cancer.

Abstract

The standard treatment for resectable pancreatic cancer is preoperative adjuvant chemotherapy (NAC) + curative surgery + adjuvant chemotherapy. Although excellent local control results of carbon ion radiotherapy (CIRT) for pancreatic cancer have been reported, no reports have compared CIRT with the standard treatment for resectable pancreatic cancer. In this study, we compared the results of CIRT for resectable pancreatic cancer with those of standard therapy and investigated the usefulness of CIRT. The subjects were 35 patients who underwent CIRT for clinical cT1-2, N0-1, and M0 cancers at Kanagawa Cancer Center, Yokohama, Japan, from September 2018 to September 2021, and 110 patients who underwent standard treatment (NAC + curative surgery + adjuvant). Overall survival (OS) and recurrence-free survival (PFS) were compared between the two groups using propensity score-matching (PSM). Twenty-three CIRT monotherapy patients were matched with NAC + curative surgery + adjuvant chemotherapy patients by PSM. Although there was no significant difference in RFS between the two groups, OS was significantly poorer in the CIRT monotherapy group than in the NAC + curative surgery + adjuvant chemotherapy group. This single-centre retrospective propensity score-matched comparison of CIRT and NAC + curative resection + adjuvant chemotherapy as the standard therapy for resectable pancreatic cancer showed an inferiority of CIRT in terms of OS, but no difference in PFS. Therefore, CIRT monotherapy may be a treatment strategy for patients with contraindications for standard treatment of curative surgery plus perioperative chemotherapy.