Concurrent Chemoradiotherapy Versus Chemotherapy Alone for Unresectable Locally Advanced Pancreatic Cancer: A Retrospective Cohort Study

PURPOSE The optimal treatment strategy for locally advanced pancreatic cancer (LAPC), particularly the role of concurrent chemoradiotherapy (CCRT), remains debatable. We compared the clinical outcomes of CCRT and palliative chemotherapy alone (CA) in patients with unresectable LAPC. MATERIALS AND METHODS Patients with LAPC who were consecutively treated between 2003 and 2010 were included. Resectability was evaluated according to National Comprehensive Cancer Network ver. 1.2012. The clinical outcomes for each treatment group (CCRT vs. CA) were evaluated retrospectively. RESULTS Sixty-three patients (58.9%) and 44 patients (41.1%) were treated with CCRT and CA, respectively. The CCRT cohort included patients who were treated with CCRT with or without chemotherapy backbone (CCRT alone, induction chemotherapy-CCRT, CCRT-maintenance chemotherapy, and induction-CCRT-maintenance chemotherapy). Median progression-free survival (PFS) and overall survival (OS) of all patients were 7.2 months and 13.1 months. PFS of the CCRT and CA groups was 9.0 months and 4.4 months, respectively (p=0.020). OS of the CCRT and CA groups was 15.4 months and 9.3 months, respectively (p=0.011). In multivariate analysis, the adjusted hazard ratio of CCRT was 0.536 (p=0.003) for OS and 0.667 (p=0.078) for PFS. Although the pattern of failure was similar in the CCRT and CA groups, the times to both local and distant failure were significantly longer in the CCRT group. CONCLUSION In patients with unresectable LAPC, those who underwent CCRT during their entire treatment courses had longer OS than patients treated with chemotherapy alone.