Long-term outcomes of robot-assisted versus minimally invasive esophagectomy in patients with thoracic esophageal cancer: a propensity score-matched study

BACKGROUND: Recently, robot-assisted minimally invasive esophagectomy (RAMIE) has gained popularity worldwide. Some studies have compared the long-term results of RAMIE and minimally invasive esophagectomy (MIE). However, there are no reports on the long-term outcomes of RAMIE in Japan. This study compared the long-term outcomes of RAMIE and MIE. METHODS: This retrospective study included 86 patients with thoracic esophageal cancer who underwent RAMIE or MIE at our hospital from June 2010 to December 2016. Propensity score matching (PSM) was employed, incorporating co-variables such as confounders or risk factors derived from the literature and clinical practice. These variables included age, sex, body mass index, alcohol consumption, smoking history, American Society of Anesthesiologists stage, comorbidities, tumor location, histology, clinical TNM stage, and preoperative therapy. The primary endpoint was 5-year overall survival (OS), and the secondary endpoints were 5-year disease-free survival (DFS) and recurrence rates. RESULTS: Before PSM, the RAMIE group had a longer operation time (min) than the MIE group (P = 0.019). RAMIE also exhibited significantly lower blood loss volume (mL) (P < 0.001) and fewer three-field lymph node dissections (P = 0.028). Postoperative complications (Clavien-Dindo: CD ≥ 2) were significantly lower in the RAMIE group (P = 0.04), and postoperative hospital stay was significantly shorter than the MIE group (P < 0.001). After PSM, the RAMIE and MIE groups consisted of 26 patients each. Blood loss volume was significantly smaller (P = 0.012), postoperative complications (Clavien-Dindo ≥ 2) were significantly lower (P = 0.021), and postoperative hospital stay was significantly shorter (P < 0.001) in the RAMIE group than those in the MIE group. The median observation period was 63 months. The 5-year OS rates were 73.1% and 80.8% in the RAMIE and MIE groups, respectively (P = 0.360); the 5-year DFS rates were 76.9% and 76.9% in the RAMIE and MIE groups, respectively (P = 0.749). Six of 26 patients (23.1%) in each group experienced recurrence, with a median recurrence period of 41.5 months in the RAMIE group and 22.5 months in the MIE group. CONCLUSIONS: Compared with MIE, RAMIE led to no differences in long-term results, suggesting that RAMIE is a comparable technique.