Stage- and age-adjusted cost-effectiveness analysis of laparoscopic surgery in rectal cancer.

BACKGROUND: It has been argued that laparoscopy should be a standard treatment in rectal cancer due to its greater technical complexity. The objective of this study was to conduct a cost-effectiveness analysis to compare laparoscopy with open surgery for rectal cancer adjusting for age and clinical stage. METHODS: A real-world prospective cost-effectiveness cohort study was conducted with data on costs and effectiveness at individual patient level. A "genetic matching" algorithm was used to correct for selection bias. After balancing the sample groups, combined multivariate analysis of total costs and quality-adjusted life years (QALYs) was performed using seemingly unrelated regression (SUR) models. These models were first constructed without interactions and, subsequently, effects of any age-stage interaction were analyzed. RESULTS: The sample included 601 patients (400 by laparoscopy and 201 by open surgery). Crude cost-effectiveness analysis indicated that overall laparoscopy was cheaper and associated with higher QALYs. The SUR models without interactions showed that while laparoscopy remained dominant, the incremental effectiveness decreased to the point that it offered no statistically significant benefits over open surgery. In the subgroup analysis, at advanced stages of the disease, although none of the coefficients were significant, the mean incremental effectiveness (QALYs value) for laparoscopy was positive in younger patients and negative in older patients. Further, for advanced stages, the mean cost of open surgery was lower in both age subgroups but differences did not reach statistical significance. In early stages, laparoscopy cost was significantly lower in the subgroup younger than 70 and higher in the older subgroup. CONCLUSIONS: The cost-effectiveness of laparoscopy in surgery for rectal cancer justifies this being the standard surgical procedure in young patients and those at initial stages. The choice of procedure should be discussed with patients who are older and/or in advanced stages of the disease. Trial registration ClinicalTrials.gov Identifier: NCT02488161.