Breast cancer FISH negative generally refers to the patient’s HER-2 index test is negative, indicating that the patient is not suitable for targeted therapy. FISH test is usually used as a kind of immunofluorescence test for patients, which is mainly used for the detection of HER-2 indicators in breast cancer patients. Immunohistochemical indicators, including ER, PR and HER-2, are usually performed on patients after surgery for breast cancer patients. When the result of HER-2 interpretation is 2+, the patient needs to undergo the examination of FISH, and if it is negative, HER-2 is determined to be negative, and if it is positive, HER-2 is determined to be positive. Generally, if it is positive, targeted therapy should be performed, and if it is negative, targeted therapy is not needed. For breast cancer FISH negative, it is recommended to go to the breast surgery department of your regular hospital.