Comparison of Transanal Endoscopic Microsurgery and Total Mesorectal Excision in the Treatment of T1 Rectal Cancer: A Meta-Analysis

BACKGROUND Transanal endoscopic microsurgery (TEM) for the treatment of early-stage rectal cancer has attracted attention due to its advantages of reduced surgical trauma, fewer complications, low operative mortality, rapid postoperative recovery and short hospital stay. However, there are still significant controversies regarding TEM for the treatment of rectal cancer, mainly related to the prognosis associated with this method. OBJECTIVE This study sought to compare the efficacy of transanal endoscopic microsurgery (TEM) and total mesorectal excision (TME) for the treatment of T1 rectal cancer. METHODS We searched the Cochrane Library, PubMed, Embase and CNKI databases. Based on the Cochrane Handbook for Systematic Reviews, we screened the trials, evaluated the quality and extracted the data. RESULTS One randomized controlled trial (RCT) and six non-randomized controlled clinical trials (CCTs) were included in the meta-analysis (a total of 860 rectal cancer patients were included; 303 patients were treated with TEM, and 557 patients were treated with TME). Analysis revealed that all seven studies reported local recurrence rates, and there was a significant difference between the TEM and TME groups [odds ratio (OR) = 4.62, 95% confidence interval (CI) (2.03, 10.53), P = 0.0003]. A total of five studies reported distant metastasis rates, and there was no significant difference between the TEM and TME groups [OR = 0.74, 95%CI (0.32, 1.72), P = 0.49]. A total of six studies reported postoperative overall survival of the patients, and there was no significant difference between the TEM and TME groups [OR = 0.87, 95%CI(0.55, 1.38), P = 0.55]. In addition, two studies reported the postoperative disease-free survival rates of patients, and there was no significant difference between the TEM and TME groups [OR = 1.12, 95%CI (0.31, 4.12), P = 0.86]. CONCLUSIONS For patients with T1 rectal cancer, the distant metastasis, overall survival and disease-free survival rates did not differ between the TEM and TME groups, although the local recurrence rate after TEM was higher than that after TME.