Breast-conserving therapy versus modified radical mastectomy in the treatment of early breast cancer in Japan.

BACKGROUND

Breast-conserving therapy has been widely utilized as a treatment option for women with early breast cancer. However, no randomized study comparing modified radical mastectomy and breast-conserving therapy has been conducted in Japan.

METHODS

Two hundred and twenty-eight Japanese women with early breast cancer enrolled in the Gunma Breast Conserving Therapy Study between 1991 and 1994 were examined to determine whether there is any difference in disease-free survival or overall survival between radical mastectomy and breast-conserving therapy. After informed consent was obtained, a total of 119 patients underwent breast-conserving therapy and 109 underwent mastectomy.

RESULTS

Mastectomy was a more frequently utilized treatment than breast-conserving therapy in patients with clinical stage II lesions, older age, larger tumor size or shorter distance between tumor and nipple. The mean follow-up period for all patients was 81 months (median 86 months). There was no significant difference in overall survival or disease-free survival between breast-conserving therapy and mastectomy even after adjusting for the clinical stage of the disease. A multivariate analysis of tumor size, lymph node status, estrogen receptor status and operation method using the Cox proportion hazard model confirmed that only lymph node status was an independent prognostic factor.

CONCLUSION

Breast-conserving therapy is comparable to modified radical mastectomy in overall survival and disease-free survival.