Effect of First-line Chemotherapy Alone Versus First-line Chemotherapy Plus Radiotherapy on Survival in Patients with Locally Advanced Pancreatic Cancer in the IMRT era: A Retrospective Cohort Study

Abstract

Abstract Purpose: The role of intensity-modulated radiotherapy (IMRT) and novel combination chemotherapy regimens in locally advanced pancreatic cancer (LAPC) remains unclear. In this study, we focused on comparing survival between first-line chemotherapy alone and first-line chemotherapy plus IMRT in patients with LAPC. Methods: Atotal of 70 patients from Shandong Cancer Hospital and Institute were enrolled. The primary endpoint was progression-free survival (PFS). Survival outcomes were estimated by the Kaplan-Meier method and compared by the log-rank test, and the multivariate Cox proportional hazards model was used to estimate hazard ratios (HRs), 95% CIs and independent prognostic factors. Results: The median PFS was 10.0 months in the chemotherapy alone group and 14.0 months in the chemotherapy plus IMRT group (P=0.465). Patients who received chemotherapy alone had a median OS of 12.0 months vs. 21.0 months for patients who received chemotherapy plus IMRT (P=0.156). The chemotherapy alone group had a disease control rate (DCR) of 33.33% (6 of 18), while the chemotherapy plus IMRT group had a DCR of 61.54% (32 of 52) (P=0.038). The multivariate Cox regression model was used to adjust for potential prognostic factors. Shorter PFS was observed in men (P=0.042), and those with a high serum level of CA 19-9 (P=0.047). Similarly, shorter OS was significantly associated with men (P=0.010) and a high serum level of CA 19-9 (P=0.020). Conclusions: The combination of first-line chemotherapy and IMRT improves the DCR rate. However, first-line chemotherapy plus IMRT had no significant difference in DFS and OS compared with chemotherapy alone.