Current status of breast cancer chemotherapy in Japan

Recent advances in breast cancer chemotherapy are reviewed with special regard to the characteristics of the disease in Japanese women, which has a low incidence rate and favorable prognosis. Long-term administration of a single drug such as cyclophosphamide (CY) was most widely used with an acceptable response rate and prolongation of survival in metastatic disease. Combination chemotherapy, mostly including mitomycin C (MMC), 5-fluorouracil (5-FU), and CY in the regimen, produced a higher response rate than single-drug treatment. Surgical adjuvant chemotherapy with MMC and CY, single or in combination, was usually beneficial for the patients in moderately advanced stages of disease but was inadequate for those in more advanced stages. Significance of estrogen receptor is discussed in relation to responsiveness to chemotherapy. Breast cancer chemotherapy in Japan includes some aspects different from those in western countries.