Long term oncological outcomes for laparoscopic versus open surgery for rectal cancer – A population‐based nationwide noninferiority study

AIM: The aim of this work was to compare the 5‐year overall survival in a national cohort of patients undergoing curative abdominal resection for rectal cancer by laparoscopic (LAP) or open (OPEN) surgery. METHOD: All patients diagnosed with clinical Stage I–III rectal cancer and who underwent LAP or OPEN abdominal curative surgery in Sweden between 2010 and 2016 were retrieved from the Swedish Colorectal Cancer Registry. A noninferiority study design was employed with a statistical power of 90%, a one‐side type I error of 2.5% and a noninferiority margin of 2%. The analyses were performed as intention‐to‐treat and the relationship between surgical technique and overall mortality within 5 years was analysed. Multilevel regression models with the patients matched by propensity scores adjusted for patient‐ and tumour‐related variables were used. RESULTS: A total of 8410 Stage I–III cancer patients were included. This group underwent 2094 LAP (24.9%) and 6316 OPEN (75.1%) procedures and were followed until 31 December 2020. Multivariable Cox regression demonstrated that 5‐year overall survival was higher in the LAP group [hazard ratio (HR) 0.877; 95% CI 0.775–0.993]. [Correction added on 21 November 2022, after first online publication: In the preceding sentence, the CI value for LAP group has been corrected from “0.877” to “0.775” in this version.] The outcome was similar when multiple imputation and propensity score matching were employed. When cT4 patients were excluded there was no difference (HR 0.885; 95% CI 0.790–1.033). At 5‐years’ follow‐up local recurrence was not different, at 2.9% for the LAP group and 3.6% for the OPEN group (p = 0.075), while metastatic disease was more frequent in the OPEN group (19.6% compared with 15.6% for LAP; p < 0.001). CONCLUSION: This study demonstrated that the LAP technique was not inferior to OPEN surgery with regard to overall 5‐year survival. These results support the use of laparoscopic surgery.