Abstract
In Japan, a new type of mass screening for breast cancer has been proposed by the Japan Association of Breast Cancer Screening-mammography performed together with a physical examination every 2-years for women over the age of 50. We are now performing breast cancer screening by physical examination alone, but a recent study showed that the present method is not reducing the mortality rate of breast cancer.
We have analyzed the cost-effectiveness of three mass screening programs for breast cancer : (1) physical examination alone, 1-year interval ; (2) mammography + physical examination, 1-year interval ; and (3) mammography + physical examination, 2-year interval. The analysis was performed using a mathematical model that we reported previously. The number life-years of women saved from breast cancer was used as a measure of effectiveness and costs included those of the screening test, of detailed examinations and of therapy. Various parameters utilized in our model were estimated based on the opinions of experts in the breast cancer research group headed by Dr. Ohuchi (Tohoku University, School of Medicine). The cost-effectiveness ratios are presented in terms of Yen/life-year saved and Yen/quality-adjusted life year saved. The latter ratio takes into consideration the benefits of breast conservation therapy, which results in a higher quality of life than mastectomy. We found that physical examination + mammography with a 2-year interval was the most cost-effective program followed by physical examination + mammography, with a 1-year interval. Physical examination, alone with a 1-year interval was the least cost-effective approach.
Consequently we conclude that performing mammography with a physical examination every 2 years is the method of choice among these three screening programs. However, further investigations should be carried out using more accurate parameters.
