What should you know about cancer spread to breast?

These situations are not classified or treated in the same way. A tumour that travelled to the breast keeps the identity of the organ where it started. Doctors use imaging, previous medical information and tissue testing to establish the origin before recommending treatment.

A new breast lump in someone with cancer can have several explanations, including a benign breast change, a new primary breast cancer, a lymph node near the breast, or spread from the known cancer. Symptoms and examination alone cannot reliably separate these causes.

A mammogram, ultrasound or breast MRI may define the location and identify other areas that need assessment. A breast biopsy can show the cell type, while specialised laboratory markers may help compare it with the original tumour. Treatment is then based on that biological identity and the extent of disease, not only on its position in the breast.

Report a new breast or armpit lump, skin dimpling, nipple inversion, nipple discharge or a persistent change in breast shape to your cancer team or a breast clinic. Note when it appeared and whether it changes, but do not delay an appointment while monitoring it.

Bring the name and treatment history of any previous cancer, along with earlier pathology or scan reports if they are held elsewhere. The clinician may review old tissue alongside a new sample. Gene expression testing or genomic tumour profiling may be considered in selected circumstances, but neither replaces the basic task of identifying where the cancer began.

Arrange prompt clinical review for a new persistent lump or rapid breast change, especially during or after cancer treatment. Seek urgent help if the breast becomes rapidly swollen, hot and red with fever or if you feel acutely unwell, because infection also requires timely treatment. Sudden breathlessness, chest pain, new weakness, confusion or a seizure warrants emergency assessment regardless of the breast finding.

Ask whether the images look more like a primary breast tumour, spread from the known cancer or a non-cancerous change; which biopsy method is appropriate; and whether old pathology will be compared with the new sample. Request a clear explanation of how the final diagnosis will influence the treatment goal and choice of therapy.