Management of early relapse ER-positive advanced breast cancer

Breast cancer is the most commonly diagnosed malignancy and leading cause of cancer deaths in Singaporean females. [1] Ninety percent of breast cancers are diagnosed at non-metastatic stages and treated with curative intent. [1] Approximately 70% of newly diagnosed invasive breast cancers are oestrogen receptor (ER) and/or progesterone receptor (PR) positive and human epidermal growth factor receptor-2 (HER2) negative. Overall, these tumors are associated with a favourable clinical behavior, favourable prognosis and with lower risk of recurrence than other breast cancer subtypes. Nevertheless, the risk of recurrence remains, especially with more aggressive tumour biology and increasing tumor burden.