Lateral lymph node dissection for mid-to-low rectal cancer: is it safe and effective in a practice-based cohort?

BACKGROUND: Most evidence regarding lateral lymph node dissection for rectal cancer is from expert settings. This study aimed to evaluate the safety and efficacy of this procedure in a practice-based cohort. METHODS: A total of 383 patients who were diagnosed with stage II–III mid-to-low rectal cancer between 2010 and 2019 and underwent primary resection with curative intent at a general surgery unit were retrospectively reviewed. After propensity matching, 144 patients were divided into the following groups for short- and long-term outcome evaluation: mesorectal excision with lateral lymph node dissection (n = 72) and mesorectal excision (n = 72). RESULTS: This practice-based cohort was characterized by a high pT4 (41.6%) and R1 resection (10.4%) rate. Although the operative time was longer in the lateral dissection group (349 min vs. 237 min, p < 0.001), postoperative complications (19.4% vs. 16.7%, p = 0.829), and hospital stay (18 days vs. 22 days, p = 0.059) did not significantly differ; 5-year relapse-free survival (62.5% vs. 66.4%, p = 0.378), and cumulative local recurrence (9.7% vs. 15.3%, p = 0.451) were also in the same range in both groups. In the seven locally recurrent cases in the lateral dissection group, four had undergone R1 resection. CONCLUSIONS: Lateral lymph node dissection was found to be safe in this practice-based cohort; however, the local control effect was not obvious. To maximize the potential merits of lateral lymph node dissection, strategies need to be urgently established to avoid R1 resection in clinical practice.