The incidence of breast cancer is increasing in Japan: 33,676 women were diagnosed with breast cancer in 2001, making it the leading cause of cancer among women since 1995. Statistical database in Exel format/outline of health welfare statistics from the Ministry of Labor, Health, and Welfare show that the number of deaths from breast cancer was 9,806 in 2003. Because the ten-year survival rate is about ninety percent in Stages 0 and I breast cancer patients, detection and treatment at an earlier stage can lead to higher survival rates. However, the recurrence rate increases as the disease progresses. In addition, about thirty percent of all breast cancer patients are believed to have recurrent disease. Thus, developing treatments against recurrence may be an important task.