To Örebro University

AIM: The aim was to compare five-year overall survival in a national cohort of patients undergoing curative abdominal resection for rectal cancer by laparoscopic (LAP) or open (OPEN) technique.

METHODS: All patients diagnosed with clinical stage I-III rectal cancer and who underwent LAP or OPEN abdominal curative surgery between 2010 and 2016 in Sweden were retrieved from the Swedish Colorectal Cancer Registry. A non-inferiority study design was employed with a statistical power of 90%, a one-side type I error of 2.5%, and a non-inferiority margin of 2%. The analyses were performed as intention-to-treat and the relationship between surgical technique and overall mortality within five years was analyzed. Multilevel regression models with the patients matched by propensity scores adjusted for patient and tumour related variables.

RESULTS: A total of 8410 cancer stage I-III patients were included whereof 2094 LAP (24.9%) and 6316 underwent OPEN (74.9%) and were followed until December 31, 2020. Multivariable Cox regression demonstrated that five-year overall survival was higher in LAP; Hazard Ratio (HR): 0.877;(95% CI: 0.877-0.993). Outcome was similar when employing multiple imputation and propensity score matching. When excluding cT4 there was no difference; HR: 0.885;(95% CI: 0.790-1.033). At five years follow up, local recurrence was not different, 2.9% in LAP and 3.6% in OPEN (P=0.075), while metastatic disease was more frequent in OPEN, 19.6% compared with 15.6% in LAP (P<0.001).

CONCLUSIONS: This study demonstrated that LAP was not inferior to OPEN with regard to overall five-year survival. These results support the use of laparoscopic surgery.

AIM: The study aimed to compare five-year overall survival in a national cohort of patients undergoing curative abdominal resection for colon cancer by minimally invasive surgery (MIS) or open (OPEN) technique.

METHODS: All patients diagnosed between 2010 and 2016 in Sweden with pathological UICC stage I-III colon cancer localized in the cecum, ascending colon, hepatic flexure or sigmoid colon, and those who underwent curative right sided hemicolectomy, sigmoid resection or high anterior resection by MIS or OPEN were included. Patients were identified in the Swedish Colorectal Cancer Registry from which all data was retrieved. The analyses were performed as intention-to-treat and the relationship between surgical technique (MIS or OPEN) and overall mortality within five years was analysed. For the primary research question a non-inferiority hypothesis was assumed with a statistical power of 90%, a one-side type I error of 2.5%, and a non-inferiority margin of 2%. For the secondary analyses, multilevel survival regression models with the patients matched by propensity scores were employed, adjusted for patient- and tumuor-related variables.

RESULTS: A total of 11605 pathological UICC cancer stage I-III patients were included with 3297 MIS (28.4%) and 8308 OPEN (71.6%) and were followed until December 31, 2020. The primary analysis demonstrated superiority for MIS compared to OPEN. The multilevel survival regression analyses confirmed that five-year overall survival was higher in MIS with a hazard ratio (HR) of 0.874 (95% confidence interval (CI): 0.791-0.965), and if excluding pT4, outcome was similar, with a HR of 0.847 (95% CI: 0.756-0.948).

CONCLUSION: This observational study demonstrated that MIS was favourable to OPEN with regard to five-year overall survival. These results support the use of laparoscopic colon cancer surgery in routine practise.