Effect of Radiotherapy in Neoadjuvant Treatment of Borderline Resectable and Locally Advanced Pancreatic Cancer: A Systematic Review and Meta-analysis.

[BACKGROUND] Pancreatic cancer is a malignant tumor with poor prognosis and bad curative effect. Previous studies did not confirm the role of radiotherapy in neoadjuvant treatment of borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC). By reviewing new findings reported in recent years, we conducted this study to evaluate the survival impact by comparing chemoradiotherapy (CRT) with chemotherapy alone.

[MATERIALS AND METHODS] PubMed, Embase, MEDLINE, Web of Science, Scopus, and Cochrane Library were searched for studies reporting median overall survival (OS) in patients with BRPC or LAPC treated with neoadjuvant treatment. Secondary outcomes included progression-free survival (PFS) or disease-free survival (DFS) or recurrence-free survival (RFS) and R0 resection rate.

[RESULTS] A total of 18 studies were included in the meta-analysis. OS (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.64-0.91, I2 = 61.7%) and PFS/DFS/RFS (HR = 0.72, 95% CI: 0.58-0.91, I2 = 52.3%) are both favored CRT. Although R0 resection rate was increased in CRT group, significant survival benefit of radiotherapy was found in LAPC and low resection rate subgroup in stratification analysis. Regression analysis showed that only tumor resectability was associated with OS.

[CONCLUSIONS] For patients with LAPC and who are unlikely to receive resection, neoadjuvant radiotherapy seems to improve OS and PFS/DFS/RFS.