How does receptor discordance in metastatic breast cancer impact overall survival rates?
Receptor discordance means that the cancer cells in a metastatic tumor have different receptor status (estrogen, progesterone, or HER2) than the original breast cancer. This can happen as the disease progresses. Studies show that when receptors change, especially when hormone receptors are lost, overall survival tends to be worse. This matters because treatment decisions often rely on the original tumor's receptor status, and discordance may mean the current treatment is no longer the best option.
What the research says
A 2021 study of 185 patients found that receptor discordance rates were 18.65% for estrogen receptor (ER), 30.57% for progesterone receptor (PR), and 16.06% for HER2 9. Patients with ER discordance had worse overall survival (OS) and post-metastasis survival (PMS), and those who lost ER had worse PMS compared to those with consistent ER positivity 9. Similarly, PR discordance and loss of PR were linked to poorer OS and PMS 9. A 2022 study of 68 patients reported even higher discordance: ER changed in 29.4% and PR in 39.7% of cases, mostly from positive to negative 10. On multivariable analysis, tumors that converted from hormone receptor (HR) positive to negative had significantly worse OS and PMS compared to tumors that stayed HR positive 10. For HER2, a 2013 review of 24 studies noted that loss of HER2 seemed to result in worse post-relapse survival and OS, though the data were often confounded by lack of targeted treatment after loss 11. Overall, receptor discordance, especially loss of hormone receptors, is consistently associated with poorer survival outcomes 91011.
What to ask your doctor
- Should I have a biopsy of a metastatic site to check if my cancer's receptor status has changed?
- If my hormone receptors are now negative, would changing my treatment improve my outlook?
- What are the risks and benefits of re-biopsy in my situation?
- How often does receptor discordance happen, and how would it affect my treatment plan?
- Are there newer treatments that might work better if my HER2 status has changed?
This question is drawn from common patient questions about Oncology and answered using cited medical research. We do not provide individualized advice.