Triple negative breast cancer: what it is, symptoms, tests and treatment

Cancer Research UK explains that triple negative breast cancers are cancers whose cells do not have receptors for oestrogen and progesterone, or for a protein called human epidermal growth factor receptor 2 (HER2). A pathologist tests a sample of the cancer, taken at biopsy or after surgery, for these receptors.

Most breast cancers do have receptors. Around 80 out of every 100 are oestrogen receptor positive, and about 15 out of 100 are HER2 positive. Triple negative cancers have none of the three, which is why they are called triple negative. Hormone therapy works by stopping oestrogen stimulating cancer cells, so it is only likely to work for oestrogen receptor positive cancers.

Cancer Research UK says the symptoms of triple negative breast cancer are similar to other breast cancer types. See your GP if you notice anything different or unusual about the look and feel of your breasts. Most breast changes are not cancer, but a new change should always be checked.

• A lump or thickening in the breast or armpit

• A change in the size, shape or feel of the breast

• Skin changes such as puckering, dimpling, a rash or redness

• Fluid leaking from the nipple in a woman who is not pregnant or breastfeeding

• A change in the position of the nipple

Cancer Research UK says the main treatments are surgery, chemotherapy and radiotherapy. Your treatment depends on where the cancer is, its size and whether it has spread (the stage), how abnormal the cells look (the grade) and your general health.

Surgery may remove an area of the breast (breast conserving surgery) or the whole breast (mastectomy), and the surgeon usually takes out some of the lymph nodes under the arm to test them, which helps to find the stage and decide further treatment. After breast conserving surgery you usually have radiotherapy to the rest of the breast.

You might have chemotherapy before surgery (neoadjuvant treatment) to shrink the cancer so the operation is possible, or so that an area of the breast can be removed instead of a mastectomy, and you usually also have chemotherapy after the operation to reduce the risk of the cancer coming back. The combination may include doxorubicin, cyclophosphamide, paclitaxel, fluorouracil, docetaxel, epirubicin, cisplatin, carboplatin or capecitabine.

Your doctor might suggest pembrolizumab, an immunotherapy drug that stimulates the immune system to fight cancer cells. You might have it with chemotherapy before surgery and then continue on its own after surgery. You might also have bisphosphonates to prevent or slow down bone thinning alongside your treatment.

Cancer Research UK says your GP refers you to a breast clinic if you have symptoms that could be due to breast cancer, and you may be referred if a screening mammogram shows an abnormal area. You usually have a mammogram, an ultrasound scan of the breast and a biopsy of breast tissue.

After a biopsy or surgery a pathologist tests the tissue and looks for hormone receptors and HER2, which is how a triple negative cancer is identified. Your doctor might also refer you for genetic testing to find out whether there is a change in the BRCA genes. Tumour profiling tests may also be used to help decide treatment after surgery for early breast cancer.

Cancer Research UK says triple negative breast cancer develops more often in women under 40 and is more common in Black women compared to White women. Men can also develop it but this is very rare.

Some women also have a change in the BRCA1 or BRCA2 genes. Everyone has these genes, and they normally stop cells growing and dividing out of control; a fault can increase the risk of breast cancer. The charity does not give a single cause for triple negative cancers, and the sources read do not link them to diet or lifestyle.

Cancer Research UK says you have regular check-ups and mammograms after treatment. How often depends on your individual situation, and you usually have a mammogram every year for at least 5 years after treatment. Contact your healthcare team if you notice a new symptom or have questions, and you can also speak to your GP.

Your doctor or nurse might ask you to take part in a clinical trial. Trials are looking at different chemotherapy, targeted drugs and immunotherapy for triple negative breast cancer, and the Cancer Research UK clinical trials database lists UK trials.

Cancer Research UK says coping with triple negative breast cancer can be difficult and that help and support is available to you and your family. It names the UK Charity for Triple Negative Breast Cancer, which provides information about TNBC and an online community, alongside the support of your breast care nurse.

On the NHS, a GP refers you urgently to a breast clinic, where triple assessment (examination, imaging and biopsy) is usually done. Treatment is planned by a multidisciplinary team including a surgeon, oncologist and breast care nurse.

Private breast clinics offer assessment and treatment too. Because the cancer type, stage and receptor results determine treatment, ask who will review your case in a multidisciplinary meeting and how the pembrolizumab and chemotherapy decisions are made.