A preliminary cost utility analysis of adjuvant chemotherapy for resected colonic carcinoma, CHERE Discussion Paper No 15

In 1990, a study was published (Moertel CG, et al 1990) which recommended a new treatment standard for colon cancer: a 52 week course of adjuvant chemotherapy. The study recommended that such a course of chemotherapy administered after surgical resection could increase five year survival from 55% to 71%. However, this recommendation raised several concerns, particularly about the quality of life of patients undergoing such a long course of chemotherapy and the costs to the health care system of such a prolonged therapy. This paper sought to address both of these issues in the context of an economic evaluation. The cost of surgery plus chemotherapy was estimated and compared with the cost of surgery alone. Descriptions of quality of life were developed from interviews with patients and health professionals, and the time trade off technique was then used to derive utility weights (from a small sample of 16) which were used to adjust length of life to reflect quality, in terms of a "quality adjusted life year" (QALY). Expected survival with and without chemotherapy was based on published data. Chemotherapy increased the total cost of treating a patient with colon cancer by $7,010 per year, from $6,012 to $13,022. The extra benefit gained from the chemotherapy was 2.4 life years. The cost per extra life year gained was therefore $2,920. Incorporating quality of life reduced this gain to 0.36 QALYs. Thus the cost per QALY gained was $19,472. The results of this analysis are only tentative, as the quality of life descriptions were not measured over time, but from a cross sectional survey of patients, and the valuations of health states were derived from a small sample. However, the results do demonstrate the importance of quality of life in the evaluation of cancer treatment.