Okumura, Y.; Nishimura, R.; Nakatsukasa, K.; Yoshida, A.; Masuda, N.; Tanabe, M.; Shien, T.; Tanaka, S.; Arima, N.; Komoike, Y.; Taguchi, T.; Iwase, T.; Inaji, H.; Ishitobi, M.; Collaborative Study Group of Scientific Research of the Japanese Breast Cancer Society