Estrogen receptor negative status [ER-]

This code indicates that a breast cancer tumor has been tested and found to lack estrogen receptors. This means the cancer cells are not stimulated to grow by the hormone estrogen. This status is a significant prognostic and predictive factor in breast cancer treatment planning.

Use this code when documentation explicitly states a patient's breast cancer is estrogen receptor negative (ER-), typically following immunohistochemistry (IHC) testing of tumor tissue. This is crucial for guiding treatment decisions, as ER- tumors do not respond to hormone therapies like tamoxifen or aromatase inhibitors.

• Ensure documentation clearly specifies "estrogen receptor negative" or "ER-".
• This code is typically used in conjunction with a malignancy code (e.g., for breast cancer).
• Do not use this code if the status is unknown, positive, or borderline; specific codes exist for those scenarios.