Oncologic Outcomes and Perioperative Clinicopathologic Results after Robot-assisted Tumor-specific Mesorectal Excision for Rectal Cancer

Robot-assisted surgery is a new and emerging surgical procedure for rectal cancer patients. However, there is a lack of information regarding oncologic outcomes for this procedure. We aimed to evaluate oncologic and perioperative clinicopathologic outcomes of surgical resection using robotic instruments for rectal cancer. Data from rectal cancer patients (n = 370) diagnosed with stage I-IV disease sited below 15 cm from the anal verge who underwent robot-assisted tumor-specific mesorectal excision consecutively from June 2006 to December 2010 were evaluated. Clinicopathologic and follow-up data were recorded prospectively and analyzed retrospectively. Perioperative clinicopathologic outcomes, postoperative complications, 3-year overall survival rate, and 3-year disease-free survival rate were analyzed. All patients underwent robot-assisted tumor-specific mesorectal excision. Of all postoperative pathologic stages, 15 (4.1 %) were stage 0 (pathologic complete remission), 126 (34.1 %) stage I, 95 (25.7 %) stage II, 118 (31.9 %) stage III, and 16 (4.3 %) stage IV. The 3-year overall survival rate was 93.1 % (pathologic complete remission = 100 %, stage I = 99.2 %, stage II = 97.1 %, stage III = 90.1 %, and stage IV = 48.4 %). The 3-year disease-free survival rate was 79.2 % (pathologic complete remission = 100 %, stage I = 93.7 %, stage II = 79.8 %, stage III = 69.6 %, and stage IV = 0.0 %). The 3-year cumulative local recurrence rate was 3.6 % (n = 10). The circumferential resection margin positive rate was 5.7 % (n = 21). Local recurrence developed in one patient and systemic recurrence developed in five patients. The total number of patients with postoperative complications was 86 (23.2 %). These data show the feasibility and safety of robot-assisted tumor-specific mesorectal excision for rectal cancer in terms of oncologic outcomes.