The majority of breast
cancers are diagnosed at an early stage, and treatment is focused on cure and prolonging disease-free survival. Local
therapy (surgery and/or
radiation treatment) is standard, along with systemic adjuvant
therapy that may effectively prevent or delay relapse and death in early-stage disease. In premenopausal women, adjuvant therapeutic approaches include combination cytotoxic
chemotherapy and endocrine
therapy.
Cyclophosphamide,
methotrexate and
5-fluorouracil (CMF) was the established
chemotherapy regimen; however, newer regimens have more recently been introduced that may offer some benefit over CMF including
anthracycline-containing regimens [e.g.
cyclophosphamide,
epirubicin and
5-fluorouracil (CEF)], and
taxane-containing regimens. For women with oestrogen receptor (ER)-positive disease, a second option is endocrine
therapy that aims to suppress mitogenic oestrogen signalling. Until recently, 5 years of
tamoxifen was regarded as the standard adjuvant endocrine treatment in ER-positive disease. Ovarian ablation is also effective in premenopausal women, and can be achieved by surgery,
radiotherapy, or via the use of a luteinising
hormone-releasing
hormone analogue such as
goserelin. Combining
tamoxifen and
goserelin treatment provides more effective oestrogen blockade than either drug alone. However, as the third-generation
aromatase inhibitors (AIs) have demonstrated improved efficacy over
tamoxifen in postmenopausal women with early and advanced disease, combination treatment with
goserelin plus an AI may provide optimal oestrogen blockade in premenopausal patients.
CONCLUSIONS: This review assesses the relative merits of chemotherapeutic and endocrine approaches for the treatment of early
breast cancer, and summarises relevant ongoing clinical trials, with an emphasis on the premenopausal setting.