[Natural history of breast cancer among Japanese and Caucasian females].
Breast cancer among Japanese females is characterized by its relatively low incidence and better prognosis than among Caucasian females. The annual mortality due to breast cancer among Japanese is about one-fifth that among Caucasians. Comparison of case distribution by histological type indicates that the ratio of well-differentiated carcinoma is slightly higher among Japanese, while the ratio of poorly differentiated carcinoma is slightly higher among Caucasian females. It is noteworthy that the incidence of in situ and invasive lobular carcinoma among Japanese is much lower than among Caucasian females. The age distribution shows that breast cancer is more frequent among middle-aged females in Japan, but more common among aged females in the West. Breast cancer among Japanese females shows a better prognosis than among Caucasian females as a whole, and even with equal tumor size and lymph node metastasis. It seems that postmenopausal breast cancer among Caucasian has a worse prognosis than the premenopausal one, although no remarkable difference in prognosis is found between premenopausal and postmenopausal patients in Japan. This suggests that the menopausal status is a critical factor for prognosis among Caucasians, but not among Japanese. As mentioned above, the morbidity and mortality rates of breast cancer among Japanese females are very low, but recently, both morbidity and mortality rates in Japan have been steeply increasing. For example, the mortality rate of breast cancer in Japan almost doubled during the past 20 years. Moreover, biological behavior of breast cancer among Japanese females has been recently changing. And time-trend data clearly indicate that breast cancer in Japan in future will be much more like that in the west, and nowadays it is westernized.
Makita
M
M
Dept. of Pathology, Cancer Institute, Tokyo.
Sakamoto
G
G
D000328:Adult; D000368:Aged; D044466:Asian People; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate; D014481:United States / Q000453:epidemiology; D044465:White People