Cost analysis of a wait-and-see strategy after radiochemotherapy in distal rectal cancer

Nonoperative management (NOM) of rectal cancer after radiochemotherapy (RtChx) in patients with a clinical complete response is an emerging strategy with the goal to improve quality of life without compromising cure rates. However close monitoring with both magnetic resonance imaging (MRI) and rectoscopy is required for the early detection of possible local regrowths. We therefore performed a cost analysis comparing the costs of immediate surgery with the costs for MRI and rectoscopy during surveillance as in the upcoming CAO/ARO/AIO-16 trial.

MRIs and rectoscopies of patients with a clinical complete response after RtChx over the course of 5 years were simulated and compared with immediate surgery after RtChx. Transition probabilities between health stages (no evidence of disease, local regrowth and salvage surgery, distant failure) were derived from the literature. Costs for ambulatory imaging and endoscopic studies were calculated according to the "Gebührenordnung für Ärzte" (GOÄ), costs for surgery based on the diagnosis-related groups system. Three different scenarios with higher costs for salvage surgery or higher regrowth rates were simulated.

A patient without disease recurrence will generate costs for MRI and rectoscopy of 6344 € over 5 years compared with costs of 14,511 € for immediate radical surgery. When 25% local regrowths with subsequent salvage surgery were included in the model, the average costs per patient are 8299 €. In our simulations a NOM strategy was cost-saving compared with immediate surgery in all three scenarios.

A NOM strategy with an intensive surveillance using MRI and rectoscopy will produce costs that are expected to remain below those of immediate surgery.