Long-term outcomes of single-incision laparoscopic surgery for colorectal cancer, a single-center, open-label, randomized controlled trial.

[BACKGROUND] The efficacy of single-incision laparoscopic surgery (SILS) for colorectal cancer remains controversial due to uncertainties regarding long-term outcomes. This study aimed to compare the 5-year outcomes of SILS and conventional laparoscopic surgery (CLS) for colorectal cancer in a randomized clinical trial.

[METHODS] This trial was a single-center, open-label, non-inferiority, randomized clinical trial conducted at our hospital. Patients aged 18-85 years who were diagnosed with or suspected of having colorectal cancer (staged cT1-4aN0-2M0) were enrolled. Neither the patients nor investigators were blinded to treatment allocation. The final follow-up date was on August 1, 2024. Participants were randomly assigned to either the SILS or CLS group in a 1:1 ratio using the random number table method. Both groups underwent surgery following the same oncological principles, including complete mesocolic excision for colon cancer and total mesorectal excision for rectal cancer with D3 lymph node dissection. The primary outcome was the early morbidity rate, which was reported previously. Here, we primarily report the long-term outcomes analyzed in the modified intention-to-treat (mITT) population, including 5-year disease-free survival (DFS), overall survival (OS), incisional hernia incidence, and recurrence patterns.

[RESULTS] A total of 200 patients were enrolled between June 28, 2017 and June 29, 2019. Of these, 193 (110 men [57.0%]; median (interquartile range [IQR]) age, 64 [15] years) were included in the mITT analysis. No patients were lost to follow-up within 5 years postoperatively. The median follow-up was 71.3 months (IQR 64.2-76.8). The 5-year DFS was 86.6% in the SILS group and 86.5% in the CLS group (hazard ratio, 1.03 [95% CI 0.47-2.21], P = 0.95). The 5-year OS rates were 88.7% and 90.6% in the SILS and CLS groups, respectively (hazard ratio, 1.26 [95% CI 0.52-3.02], P = 0.61). No statistically significant differences were observed between the two groups in terms of recurrence patterns, incisional hernia incidence, or recurrence and survival rates stratified by tumor stage.

[CONCLUSIONS] SILS, when performed by experienced surgeons, can be considered a promising alternative for selected colorectal cancer patients. This potentially expands the range of surgical treatment options available to both patients with colorectal cancer and surgeons.