Health Economics of Breast Cancer

Breast cancer is a major cause of morbidity and mortality. Resources are spent in order to prevent, diagnose, and treat breast cancer. Since health care resources are limited, these resources must be allocated in an optimal way in order to maximise health. Currently, there are several different interventions available for breast cancer, and new interventions are under development. As new technologies are developed, it is important to evaluate if these new technologies produce improvements in health at an acceptable cost compared to the older technologies. The purpose of this thesis was to contribute to the development in health economics of breast cancer. The specific aspects addressed were the cost of illness of breast cancer, the cost and quality of life in different states of breast cancer, and economic evaluations of breast cancer interventions. The cost of illness of breast cancer in Sweden was estimated using a prevalence based top-down approach. The total cost of breast cancer in 2002 in Sweden was estimated to approximately 3 billion SEK. Direct costs accounted for about 30% of the total cost, with indirect costs accounting for the remaining 70%. For direct costs, the main cost item was hospitalisation, followed by outpatient visits. For indirect costs, productivity losses due to mortality was the main cost driver. Resource use, cost and health related quality of life in different states of breast cancer were estimated based on a naturalistic observational study. Breast cancer was found to be associated with both substantial direct and indirect costs. The total cost was found to be higher for patients in their first year after primary breast cancer, for patients in their first year after a recurrence, and for patients with metastatic disease compared to patients in their second and following years after a primary breast cancer or recurrence. For patients aged less than 65, indirect costs accounted for a majority of the total cost. The study also found breast cancer to be associated with a reduction of the health related quality of life. This reduction was most pronounced for patients with metastatic disease. For all the different disease states, this reduction seems to be driven by pain and discomfort as well as anxiety and depression. Two computer simulation models were developed to project costs and benefits for treatments of breast cancer in the metastatic setting and the adjuvant setting respectively. Health economic data collected in the naturalistic observational study were used in the models. The cost-effectiveness of trastuzumab and chemotherapy compared to chemotherapy alone was estimated for Swedish women with metastatic breast cancer. In the adjuvant setting, the cost effectiveness of one year of adjuvant trastuzumab after adjuvant chemotherapy compared to adjuvant chemotherapy alone was estimated. In both the metastatic and the adjuvant setting, the addition of trastuzumab was found to be cost-effective. This thesis presents new information about the economic burden of breast cancer, as well as new data on the cost and quality of life for patients in different states of breast cancer. These data represent an important input for economic evaluations of breast cancer interventions, and will improve future economic evaluations of breast cancer. The economic evaluations presented in this thesis can be used for informed decisions about resource allocation for patients with breast cancer within the healthcare system. LIST OF PUBLICATIONS This thesis is based on the following original papers, which will be referred to by their Roman numerals: I. Lidgren M, Wilking N, Jönsson B. Cost of breast cancer in Sweden 2002. European Journal of Health Economics, 2007;8(1):5-15 II. Lidgren M, Wilking N, Jönsson B, Rehnberg C. Resource use and costs associated with different states of breast cancer. International Journal of Technology Assessment in Health Care, 2007;23(2):223-231 III. Lidgren M, Wilking N, Jönsson B, Rehnberg C. Health related quality of life in different states of breast cancer. Quality of Life Research, April 28, 2007 IV. Lidgren M, Wilking N, Jönsson B, Rehnberg C. Cost-effectiveness of HER2 testing and trastuzumab therapy for metastatic breast cancer. Submitted V. Lidgren M, Jönsson B, Rehnberg C, Wilking N, Bergh, J. Cost-effectiveness of HER2 testing and 1 year adjuvant trastuzumab therapy for early breast cancer. Submitted