Changing practices in the surgical treatment of breast cancer in Japan: a nationwide survey by the Japanese Breast Cancer Society.

A nationwide survey in Japan of the patients with primary breast cancer from 1989 to 1991 revealed marked changes in the surgical treatment of the disease. During this period, there was a significant trend toward fewer instances of radical and extended radical mastectomies, and an increase in modified radical mastectomies and breast-conserving surgery. The percentage of breast-conserving surgery for the early-stage disease increased from 6.8% to 12.7%. Among the types of operations for breast-conserving surgery, quadrantectomy was used for 51.5% of the cases, while either a partial mastectomy or a subcutaneous mastectomy was used for 18.2% and 18.9%, respectively; a lumpectomy was performed in 10.9% of the cases. As for the proportion of patients receiving radiation therapy after breast-conserving surgery, 77% of those undergoing lumpectomy received radiation, in contrast to only 43% of the patients undergoing quadrantectomy. According to the data from 1991, we also found that breast-conserving surgery was performed more often in larger cities and urban areas in Japan. As a result, we found that substantial changes in the treatment of localized breast cancer had taken place from 1989 to 1991. Regarding the details of breast-conserving surgery, however, some variation still remains in spite of the publication of numerous clinical trials.