Primary Objective:~- Determine the impact of early chemotherapy (i.e., capecitabine) versus endocrine therapy-based regimen on anti-tumor effect in patients with non-Luminal A hormone receptor-positive (HR+) metastatic breast cancer~Secondary Objectives:~Compare the safety and tolerability of capecitabine versus endocrine therapy in patients with non-Luminal A hormone receptor-positive (HR+) metastatic breast cancer~Determine the impact of early chemotherapy (i.e., capecitabine) versus endocrine therapy-based regimen on anti-tumor effect in patients with non-Luminal A hormone receptor-positive (HR+) metastatic breast cancer~Correlatives:~Determine if the tumor mutations detected in cfDNA are early surrogates of response~Determine if the cfDNA results at disease progression show new genomic alterations potentially associated with resistance to therapy
This is an open-label, multicenter, two-arm Phase II clinical trial that will evaluate the impact of 2nd line chemotherapy (i.e. capecitabine) on survival in patients with non-Luminal A hormone receptor-positive (HR+) metastatic breast cancer (MBC)