[Breast cancer in Japan--past trend and future prospect]

Breast cancer among Japanese females was characterized by a relatively low incidence and good prognosis. But recently its morbidity is increasing and its biological behavior is changing. The chronological changes and prospective features of breast cancer among Japanese females are follows: 1. Increase of morbidity and mortality 2. Increase of the ratio of poorly differentiated carcinoma and decrease of well differentiated carcinoma 3. Increase of the incidence of lobular carcinoma 4. Increase of the case of the aged females Above items show that breast cancer among Japanese females is becoming westernizing. The case-control study on "breast cancer occurrence and obesity" shows that an obesity of the aged is a significant high risk factor for breast cancer occurrence. There fore, it would be effective that the prevention of overweight at the postmenopausal women to reduce the breast cancer occurrence. The chronological rise of overall 10-year survival rate of operated breast cancer is caused by increasing the ratio of early stage cases. Suggesting an importance of regular self-examination of the breast. Furthermore, it is important to establish an adjuvant therapy without causing side effect for curatively operated cases. Concerning the cancer of the uterus among Japanese females, the chronological occurrence rate of endometrial cancer is increasing, while the death rate of cervical cancer is decreasing.