Approximately 3.5% to 4% of women with newly diagnosed breast cancer are found to have stage IV disease at presentation according to the Surveillance, Epidemiology, and End Results (SEER) dataset.1 Despite the fact that this subgroup of patients comprise the minority of the total breast cancer population, this small fraction of breast cancer patients has inspired a heated debate in the literature and at national meetings, fueled by the rapid publication rate on this subject over the past decade. To date, all published reports on this topic are limited to retrospective reviews and meta-analyses. There are several hypotheses as to why extirpation of the primary breast tumor may or may not benefit overall disease-free progression and/or survival despite known distant metastatic sites. There is also a growing body of literature on the potential benefits of metastastectomy of isolated sites. These retrospective data have led to the development of three international, multi-institutional randomized trials to study this question. This chapter will review the published reports to date for both primary tumor removal and distant metastastectomy, discuss the potential beneficial and adverse biological events secondary to primary tumor resection, and summarize the randomized trials currently accruing patients.
STAGE IV BREAST CANCER
Historical Treatment Perspective
Surgery with curative-intent is the cornerstone of treatment for women with stage 0–III breast cancer. Stage IV metastatic breast cancer is defined by the spread of tumor cells beyond the breast, chest wall, and/or regional lymph nodes. The treatment goals in patients with stage IV breast cancer are aimed at controlling the extent of disease, prolonging survival, maintaining quality of life, and limiting the symptoms related to the breast cancer and/or its treatment complications. These goals are typically achieved with systemic therapies, including chemotherapy, endocrine therapy, and/or targeted therapy (i.e., trastuzumab for Her2-amplified disease). Locoregional therapies are generally reserved for palliation. For instance, radiotherapy is often employed for symptomatic bone metastases. Historically, surgical treatment for stage IV breast cancer has been reserved only for cases when the primary tumor has led to complications, such as skin ulceration, infection with foul drainage, or life-threatening bleeding.2
The overall prognosis for patients with stage IV breast cancer is poor, and most patients will die of their breast cancer rather than other noncancer causes. However, the prognosis has dramatically improved over the past several decades, increasing from a 5-year survival of 5% to 10% in the 1970s to 30% to 40% in the early 2000s.1,3 Further, prognosis can vary widely among patients with stage IV breast cancer according to a myriad of patient and tumor factors. Location of metastatic disease has been shown to correlate with survival in women with stage IV breast cancer: less than 6 months for visceral metastases, 18 months for nodal disease, and 3 to 4 years for bone-only metastases.4 The ...