[Systemic adjuvant chemo-endocrine therapy after breast conservation treatment for breast cancer]

Abstract

The majority of patients who have undergone breast conserving surgery proved to be node-negative. Node-negative breast cancer has a fairly good prognosis, achieving a 10 year disease-free survival rate of 88%. Patterns of recurrence and relapse in node-negative cases are characterized by a higher ratio of hematogenous metastases after relatively longer disease-free intervals. Such cases have been considered the best indications of systemic adjuvant therapy. Postoperative adjuvant trials using cyclophosphamide (CPA) and/or tamoxifen (TAM) were conducted at the Aichi Cancer Center Hospital, and the following results were obtained concerning adjuvant treatment for early-stage (node-negative or stage I) breast cancer; (1) In the post-menopausal group, CPA and/or TAM administration was recommended as the treatment of choice. (2) In the postmenopausal group, TAM was evaluated as the key drug. After TAM alone or TAM plus CPA administration, an improvement in the disease-free survival rate was expected. (3) After administration of CPA alone in the postmenopausal group, there were no demonstrable benefits. On the contrary, adverse effects were suspected. (4) The risk of contralateral breast cancer was reduced to two-thirds when TAM was administered as an adjuvant therapy.