Effect of First‐Line Chemotherapy Alone Versus First‐Line Chemotherapy Plus Radiotherapy on Survival in Patients With Locally Advanced Pancreatic Cancer in the <scp>IMRT</scp> Era: A Retrospective Cohort Study

BACKGROUND: 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: A total 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 versus 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). Grade 3-4 fatigue or asthenia, decreased appetite, neutrophil count decreased, AST increased, and ALT increased were predominant in the chemotherapy alone group. CONCLUSION: The combination of first-line chemotherapy and IMRT improves the DCR rate (p = 0.038) and was well tolerated. However, first-line chemotherapy plus IMRT had no significant difference in PFS (p = 0.465) and OS (p = 0.156) compared with chemotherapy alone.