What is the role of chemotherapy in estrogen receptor-positive, advanced breast cancer?

Most breast tumors depend on female sex hormones for development and growth, thus being amenable to endocrine therapies. In the management of estrogen receptor (ER)-positive, advanced breast cancer, conventional wisdom dictates the use of endocrine therapy for patients with good prognostic features, whereas chemotherapy is recommended for the treatment of visceral crisis. There is, however, considerable uncertainty regarding the best initial strategy for patients with poor prognostic features other than visceral crisis, such as small-volume visceral involvement and a short disease-free interval after adjuvant therapy. In this article, we examine the role of chemotherapy in ER-positive, advanced breast cancer. Our review of the literature suggests that, in the absence of visceral crisis, endocrine agents should always be considered a major option for the initial treatment of ER-positive, metastatic breast cancer due to their proven efficacy and favorable toxicity profile. Although certain chemotherapy agents can induce higher response rates and more rapid responses, which are desirable effects in particular situations, the up-front use of chemotherapy does not seem to influence the overall outcome of the disease. In the subset of patients with epidermal growth factor type 2-positive disease, on the other hand, current data still do not support the use of endocrine agents alone.