A meta-analysis of the efficacy of postoperative adjuvant radiotherapy and non-radiotherapy for extrahepatic cholangiocarcinoma and gallbladder carcinoma

Objective To compare the efficacy of postoperative adjuvant radiotherapy and non-radiotherapy in patients with extrahepatic cholangiocarcinoma and gallbladder carcinoma by a meta-analysis. Methods The controlled clinical trials of postoperative adjuvant radiotherapy versus non-radiotherapy of extrahepatic cholangiocarcinoma and gallbladder carcinoma were searched from PubMed, EMbase, Cochrane Library, Wanfang database, CNKI, Chongqing VIP and CBM databases. The obtained data were analyzed using RevMan 5.3 and Stata 14.0 statistical software. The difference between two groups was estimated by calculating the odds ratio (OR) with 95% confidence interval (CI). Results A total of 20 controlled clinical trials involving 1258 extrahepatic cholangiocarcinoma and gallbladder carcinoma patients were included in this meta-analysis. The meta-analysis demonstrated that the 5-year survival rate in the adjuvant radiotherapy group was significantly higher than that in the non-radiotherapy group (OR=1.67, 95%CI: 1.29-2.18, P=0.001). The 5-year survival rates in those with lymph node positive disease (OR=7.44, 95%CI: 1.24-44.72, P=0.03) and positive margins disease (OR=3.43, 95%CI: 1.56-7.75, P=0.002) were significantly enhanced by postoperative adjuvant radiotherapy. The local recurrence rate in the adjuvant radiotherapy group was significantly lower than that in the non-radiotherapy group (OR=0.56, 95%CI: 0.39-0.80, P=0.01), whereas the distant metastasis rate did not significantly differ between two groups (OR=1.22, 95%CI: 0.86-1.73, P=0.27). The incidence rates of acute toxicity and chronic toxicity of grade ≥3 caused by radiotherapy were 0-11.9% and 0-21.7%, respectively. Conclusion Compared with non-radiotherapy, postoperative adjuvant radiotherapy is a safer and more effective postoperative treatment for extrahepatic cholangiocarcinoma and gallbladder carcinoma. Key words: Extrahepatic cholangiocarcinoma/radiotherapy; Gallbladder carcinoma/radiotherapy; Adjuvant therapy; Meta-analysis