Clinical Study attributes
Breast Cancer (BC) is one of the most frequent cancers in women and is the most frequent cause of death in the female population. It represents 18% of all female cancers in the world.1 The incidence varies in different populations with almost half of the cases having their origin in North America and Western Europe. In Egypt, according to the National Population-Based Cancer Registry published in 2014, BC was the most frequent cancer among females representing 32% of all female cancers2 Metastatic disease occurs in approximately 20-50% of patients with early BC history and in 6-10% of newly diagnosed BC cases.3 Since patients with metastatic BC form a heterogeneous population, treatment recommendations ought to be made on an individual basis, considering hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status, metastasis-free interval (MFI), response to and cumulative doses of previous therapy, location and extent of metastases and symptoms 4,5. Two thirds of BC patients have HR-positive (HR+) tumors 6, for whom endocrine therapy (ET) is the preferred initial treatment for metastatic disease as recommended in the treatment guidelines, even in the presence of visceral metastases 4, 6, 7. The use of ET is supported by data showing a therapeutic benefit with less toxicity and better quality of life in comparison to chemotherapy (CT) 5,8,9. Nevertheless, it is generally thought that CT is associated with greater and earlier tumor response, especially in the case of high burden of disease. For patients with hormone receptor-positive and HER2+ disease CT plus HER2-targeted therapy was strongly recommended, except for highly selected cases for whom clinicians may offer ET 10. On the contrary, for women with hormone receptor-positive HER2-negative disease who are the scope of this study the question of whether to use CT or ET as first-line treatment for metastatic BC remains, to date, partially unresolved.
