Efficacy of primary tumor resection for metastatic colorectal cancer with unresectable metastases: a Meta analysis

Abstract

Objective To evaluate the efficacy and safety of primary tumor resection for metastatic colorectal cancer with unresectable metastases. Methods Database including PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedicine and Wanfang Database were searched with the key words of asymptomatic, primary, resection, metastatic, stage Ⅳ, cancer, colon, colorectal, rectal, 无症状性, 原发灶切除, 转移性, 4期(Ⅳ期), 结直肠癌, 结肠癌, 直肠癌between the database establishment and August 2015. Literatures about primary tumor resection or systemic treatment as first-line treatment for asymptomatic patients with unresectable metastatic colorectal cancer were retrieved, and data were extracted and evaluated by 2 independent researchers. Patients with primary tumor resection as first-line treatment were allocated to the primary tumor resection group and patients with systemic treatment as first-line treatment were allocated into the systemic treatment group. The overall survival rate and median survival time were compared between the 2 groups. The incidence of perioperative complications and mortality in the primary tumor resection group as well as the incidences of intestinal obstruction and emergency operation in the systemic treatment group were evaluated. Survival data were presented by the odds ratio (OR) and 95% confidence interval (CI). Single rate data were presented as rate (r) and 95%CI. The median survival time was analyzed using the mean difference (MD) and 95%CI. Heterogeneity of the publication was analyzed using the I2 test. Results Ten retrospective control studies including 1 434 patients were retrieved. There were 770 patients in the primary tumor resection group and 664 patients in the systemic treatment group. The results of Meta analysis showed that overall survival rate of patients in the primary tumor resection group was better than that in the systemic treatment group (OR=1.35, 95 %CI: 1.01-1.79, P<0.05), and there was a longer median survival time of 3.8 months in the primary tumor resection group (MD=3.78, 95% CI: 3.60-3.97, P<0.05). The incidence of perioperative complications and mortality in the primary tumor resection group were 22% (95%CI: 0.13-0.30) and 1% (95%CI: 0.00-0.03), respectively. The incidences of intestinal obstruction and emergency surgery were 18% (95%CI: 0.14-0.21) and 11% (95%CI: 0.06-0.16) in the systemic treatment group, respectively. Conclusions For asymptomatic patients with unresectable metastatic colorectal cancer, resection of the primary tumor is safe and feasible, and it can improve the overall survival rate of patients and median survival time. The incidence of intestinal obstruction is higher among asymptomatic patients who do not receive primary tumor resection. Key words: Colorectal neoplasms; Unresectable metastases; Primary tumor resection; Meta-analysis