Role of rebiopsy in metastatic breast cancer at progression.

Alteration of biomarkers is well-documented in breast cancer at locoregional recurrence or metastasis attributed to tumor heterogeneity and change in biology. There is a lack of literature on alteration of biomarkers in metastatic breast cancer (MBC) at progression. We included 32 patients of upfront MBC. Estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2/neu documented at baseline and at progression. Median age was 46 (range 26-72) years. Estrogen receptor altered in 6 (18.75%) patients [4 (12.5%) positive to negative and 2 (6.25%) from negative to positive], progesterone receptor altered in 8 (25.3%) patients (6 [18.75%] positive to negative and 2 [6.25%] negative to positive) and human epidermal growth factor receptor 2/neu altered in 5 (15.6%) patients (all were positive to negative). Therapy was changed as per new receptor status. Documentation of change in receptor status may be justified to determine further therapy and prognosis in MBC at progression.