[Comparison of immune response after laparoscopic and open surgery for colorectal carcinoma: a meta-analysis]

To compare the immune function after laparoscopic surgery (LS) and conventional open surgery(OS) for colorectal cancer (CRC).

PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Database were systematically searched for randomized controlled trials published before August 2013 concerning the immunological difference between LS and OS. Data extraction was performed independently by two reviewers and data analysis was performed using Review Manager ver. 4.3.1.

Twelve studies including 638 patients (307 in LS group and 331 in OS group) were eligible for analysis. Overall analysis demonstrated that no significant differences were identified for blood C-reactive protein level on postoperative days (POD) 0-1 (P=0.40), plasma lymphocyte count on POD 1-3 (P=0.92) and POD 4-7 (P=0.64), plasma CD4⁺ T cell count on POD 1-7 (P=0.63), plasma CD8⁺ T cell count on POD 4-7 (P=0.09), and plasma NK cell count POD 1-3 (P=0.34) as well as POD 4-7 (P=0.46). Data analysis also showed that a significantly lower serum level of IL-6 on POD 0-1 after LS (WMD=-25.03, 95% CI:-34.06 to -15.99, P=0.000), and a significantly higher plasma level of CD8⁺ T cell count on POD 1-3 after LS(WMD=0.05, 95% CI:0.01 to 0.08, P=0.004).

Although postoperatively short-term humoral immune function trends to be better after LS for CRC compared to OS, there is no sufficient evidence to support superior preservation of global immune function after acute reactive phase.