OBJECTIVES

Rectal cancer is a major cause of morbidity and mortality in the United States. Development and validation of newer technologies has made the treatment for locally advanced rectal cancer a moving target. The study was undertaken to evaluate the cost-effectiveness of short-course (SC) radiotherapy (RT) against long-course (LC) chemoradiotherapy (CRT) in the treatment of stage III rectal cancer from the US societal perspective.

METHODS

A four state Markov model was developed for this evaluation. Health outcomes and costs were discounted at 3% annually. The Trans-Tasman rectal trial informed the patient population and initial transition probabilities. Preoperative and postoperative treatment costs were evaluated using both CPT codes and the Veteran Affairs Federal Supply Schedule (FSS). Health state utilities were based on prior publications. One-way and probabilistic sensitivity analyses (PSA) were conducted to estimate the model’s robustness.

RESULTS

SC RT dominated LC CRT. It yielded 0.07 more life years and 0.08 QALYs while costing more than $23,000 less. The resulting incremental Net Monetary Benefit (NMB) at baseline was over $34,000 in favor of SC RT at $150,000 willingness-to-pay (WTP) threshold. The one-way sensitivity analysis showed that the probability of distant recurrence in either arm was the most sensitive parameter, while the PSA illustrated the similarities between the two arms in terms of both costs and QALYs. In all, SC had a 70-71% likelihood of being cost-effective at WTP threshold of $100,000 or higher.

CONCLUSIONS

To date, this is the first cost effectiveness model evaluating SC RT and LC CRT from the US societal perspective. The base case and PSA outcomes demonstrate that SC RT is likely more cost-effective. Distant recurrence is the main driver of morbidity, mortality, and costs in this model. Future research should focus on providing robust cost and health state utility estimates for these patients.