Model-based evaluation of the cost effectiveness of 3 versus 6 months' adjuvant chemotherapy in high-risk stage II colon cancer patients

Gabrielle Jongeneel; Marjolein J E Greuter; Felice N van Erning; Miriam Koopman; Geraldine R Vink; Cornelis J A Punt; Veerle M H Coupé

doi:10.1177/1756284820954114

Model-based evaluation of the cost effectiveness of 3 versus 6 months' adjuvant chemotherapy in high-risk stage II colon cancer patients

Therap Adv Gastroenterol. 2020 Sep 16:13:1756284820954114. doi: 10.1177/1756284820954114. eCollection 2020.

Authors

Gabrielle Jongeneel¹, Marjolein J E Greuter², Felice N van Erning³, Miriam Koopman⁴, Geraldine R Vink³, Cornelis J A Punt⁵, Veerle M H Coupé²

Affiliations

¹ Department of Epidemiology and Biostatistics, Amsterdam UMC, VU University, PO Box 7057, MF F-wing, Amsterdam, 1007 MB, The Netherlands.
² Department of Epidemiology and Biostatistics, VU University, Amsterdam, The Netherlands.
³ Department of Research and Development, Netherlands Comprehensive Cancer Organization (IKNL), Utrecht, The Netherlands.
⁴ University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
⁵ Department of Medical Oncology, University of Amsterdam, Amsterdam, The Netherlands.

Abstract

Background: Our aim was to evaluate the cost effectiveness of 3 months' adjuvant chemotherapy versus 6 months in high-risk (T4 stage + microsatellite stable) stage II colon cancer (CC) patients.

Methods: Using the validated PATTERN Markov cohort model, which simulates the disease progression of stage II CC patients from diagnosis to death, we first evaluated a reference strategy in which high-risk patients were treated with chemotherapy for 6 months. In the second strategy, treatment duration was shortened to 3 months. Both strategies were evaluated for CAPOX (capecitabine plus oxaliplatin) and FOLFOX (fluorouracil, leucovorin and oxaliplatin). Based on trial data, we assumed that shortened treatment duration compared with a 6-month regimen was equally effective for CAPOX and less effective for FOLFOX. Adverse events were highest in the 6-month strategy. Analyses were conducted from a societal perspective using a lifelong time horizon. Outcomes were number of CC deaths per 1000 patients and total discounted costs and quality-adjusted life-years (QALYs) per patient (pp). Incremental net monetary benefit (iNMB) was calculated using a willingness-to-pay value of €50,000/QALY.

Results: For CAPOX, the 6-month strategy resulted in 316 CC deaths per 1000 patients, 6.71 QALYs pp and total costs of €41,257 pp. The 3-month strategy resulted in an equal number of CC deaths, but higher QALYs (6.80 pp) and lower costs (€37,645 pp), leading to a iNMB of €8454 per person for 3 months versus 6 months. For FOLFOX, the 6-month strategy resulted in 316 CC deaths per 1000 patients, 6.71 QALYs pp and total costs of €47,135 pp. The 3-month strategy resulted in more CC deaths (393), lower QALYs (6.19 pp) and lower costs (€44,389 pp). An iNMB of -€23,189 was found for 3 months versus 6 months.

Conclusion: Our findings indicate that 3 months' adjuvant chemotherapy should be considered as standard of care in high-risk stage II CC patients for CAPOX, but not for FOLFOX.

Keywords: adjuvant chemotherapy; colon cancer; cost effectiveness; treatment duration.

Grants and funding

ZONMW_848015007/ZONMW_/ZonMw/Netherlands