Gogia A, Deo SVS, Sharma D, et al. - Researchers aimed at generating data on discordance in biomarker expression [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu)] in metastatic breast cancer in cases from developing countries, such as India, via this ambispective review. In patients with breast cancer who developed metastasis at recurrence (N = 103 patients), they analyzed biomarker status and clinical and radiologic parameters, both at baseline and subsequent follow-up. For ER, PR, and HER2/neu receptor, the presence of discordance was reported in 21.3%, 29.1%, and 15.5%, respectively. Positive to negative ER and negative to positive was reported in 7.8% and in 13.6%, respectively. Positive to negative PR and negative to positive PR was seen in 21.4% and 7.8%, respectively. Single-site metastasis was detected in 41 patients (40%). Overall 62 patients (60%) had more than one site of metastasis. Visceral—lung and liver—followed by bone, nonregional lymph node, skin, and brain were documented as the most common sites of metastasis. Change in tumor biology was shown to characterize metastatic disease evolution in breast cancer and accounted for discordance in receptor status. It is justified to perform repeat biomarker studies at metastatic recurrence, particularly if treatment plans include hormone and targeted therapy.