What should you know about ER PR HER2 breast cancer?

ER means oestrogen receptor and PR means progesterone receptor. A receptor-positive result means the cancer cells have proteins that can receive signals from these hormones. HER2 is a growth-related protein; a HER2-positive result means the cells have more HER2 activity than expected. A pathology report may describe one, two or all three markers, and the result is interpreted alongside tumour size, grade, lymph-node findings and overall health.

These markers are measured on tissue obtained during a breast biopsy or surgery. ER or PR positivity can support the use of hormone-blocking treatment. HER2 status can support treatment directed at HER2. A tumour can be hormone-receptor positive and HER2 positive, hormone-receptor positive and HER2 negative, or negative for all of these markers. The report may also mention whether a result is weak, borderline or not detected; your specialist can explain how that wording affects the plan.

Marker results do not, on their own, describe the full stage or outlook of the cancer. Imaging and lymph-node assessment may be needed to understand where the disease is located. Your team may discuss a mammogram, breast MRI or sentinel lymph node biopsy depending on the findings.

Keep the pathology report and ask which results are positive, negative, borderline or still pending. Ask how the markers fit with the cancer stage and grade, and whether another tissue review or test is needed. Depending on the situation, a breast cancer gene expression test or genomic tumour profiling may add information about treatment planning. Do not start, stop or change hormone medicines, supplements or cancer treatment without discussing it with your oncology team.

Treatment may involve surgery, radiation, hormone-blocking medicines, chemotherapy, HER2-directed medicines, or a combination. The appropriate sequence depends on the complete assessment rather than on one marker alone.

Contact your cancer team promptly if you develop a new or worsening symptom during assessment or treatment, especially fever, increasing redness or drainage from a wound, uncontrolled vomiting, or difficulty keeping fluids down. Seek emergency help for severe difficulty breathing, chest pain, fainting, sudden weakness, a new seizure, or sudden confusion. These symptoms need assessment because they can have several causes, including treatment-related problems, and should not be judged from ER, PR or HER2 status alone.

Bring the exact pathology wording to your appointment. Useful questions include: Which ER, PR and HER2 results apply to my tumour? Were any results borderline or repeated? What do the stage, grade and lymph-node findings add? Which treatments are being considered, and what side effects should I report urgently? Would additional imaging or genomic testing change the plan?