Breast cancer has seen amazing improvements in survival rates thanks to research. But there are many types of breast cancer, and not all have benefitted equally from this progress. Triple negative breast cancer (TNBC) is particularly feared, with no targeted treatments currently available. But in labs around the world real progress is being made, giving us genuine hope that the outlook of triple negative breast cancer is set to change.
Ask the TNBC experts
We recently went behind the scenes at one of our labs to meet Dr Klaus Pors, who you are helping us fund to work with researchers in South Africa on a new targeted treatment for TNBC. That same week, we sat down with Dr Caroline Michie - a consultant medical oncologist with years of experience treating breast cancer patients, to ask what this breakthrough could mean for the future. Watch the video to hear from them directly.
What is triple negative breast cancer (TNBC)?
When breast cancer is diagnosed and a biopsy is taken, the cells are tested to understand what specific type of breast cancer a patient has. Breast cancer cells can have receptors on the outside which are sensitive to different proteins, which help the cancer grow.
These proteins include the hormones oestrogen and progesterone, as well as a protein called HER2. Understanding if a breast cancer has these receptors helps doctors decide the best treatment for patients. TNBC cells test negative for all three of these receptors, hence 'triple negative'.
While advanced TNBC is still seen as an incurable disease, new treatment options are starting to change this status quo and provide real hope for the future.
If we treated, for example, patients 30 or 40 years ago, we would normally just treat them with normal chemotherapy. Now we understand more that actually breast cancer is not just one disease, it's a number of different separate diseases and each molecular subtype can be treated in a different way.
Causes, diagnosis and treatment of TNBC:
What causes triple negative breast cancer?
Like all types of breast cancer, anybody can be diagnosed with TNBC, and the causes are similar to those of other breast cancer types. The risk of getting breast cancer can increase with factors like alcohol consumption, smoking, or living with obesity.
For TNBC in particular, inherited genetics do play a role and TNBC can run in families. People with mutations in their BRCA1 or BRCA2 genes are more likely to develop certain types of cancer, including breast cancer. About 70% of breast cancers diagnosed in people with a BRCA mutation are TNBC and BRCA1 seems to play a bigger role than BRCA2 mutations.
Overall, a person has a higher risk of developing TNBC if they:
Are Black or Hispanic
Are under 50 years old
Have a BRCA mutation
Are not breastfeeding
Are obese or overweight
Have high breast density
How is triple negative breast cancer diagnosed?
Like other breast cancer types, TNBC is often found during breast screening. Most diagnoses will involve a referral to a specialist breast clinic and potentially mammograms, ultrasounds and a biopsy.
During a biopsy, a sample is taken from the tumour and analysed to check for oestrogen receptors, progesterone receptors and HER2 protein – if all three tests come back negative, the diagnosis is usually TNBC.
How is triple negative breast cancer treated?
TNBC is most commonly treated with a combination of surgery, chemotherapy, and radiotherapy, however some patients have been found to benefit from immunotherapy. Atezolizumab, the first immunotherapy available on the NHS for certain types of TNBC, helps the immune system to attack cancer cells by blocking an immune system break called PD-L1.
Other promising new therapies include PARP inhibitors, such as olaparib, which are already available in the USA for certain types of breast cancer with BRCA mutations. However, there are currently no targeted treatments for TNBC. That's why we're funding research around the world to give pateients more treatment options and more hope for the future.
What makes triple negative breast cancer less survivable?
While TNBC can be treated, it is one of the more challenging breast cancers to cure, and it is often one of the more feared breast cancer diagnoses for patients, for a number of reasons.
Unfortunately, TNBC tends to spread earlier and faster to other organs, such as the brain, lung, liver and bones, than other types of breast cancer, and it also tends to be a higher grade of tumour when detected.
As TNBC is lacking the proteins that are targeted by hormonal and targeted therapies, the treatment options are more limited. TNBC can also quickly become resistant to treatemnts, and unfortunately it is more likely than other types of breast cancer to come back after treatment, within the first four years of diagnosis.
Ultimately we want people to be able to move on after breast cancer. Once its been treated they can get on with their life and not be left with these constant memories of what they've been through.
How can we make a difference for TNBC patients?
With the support of our Curestarters, we fund international cancer research to better understand how to diagnose, prevent, and treat triple negative breast cancer, so that fewer lives are cut short in the future:
Dr Hector Peinado
Dr Peinado and his team want to uncover the mechanism behind how living with obesity can make it easier for TNBC to grow and spread, to help develop methods to stop this from happening.
Dr Greta Varchi
Dr Varchi and her team are developing a highly innovative way to deliver treatments directly to the tumour, which they hope could reduce side effects and improve the effectiveness of the treatment.
Prof. Robert Kerbel
Professor Kerbel and his team have discovered a treatment approach that could lead to a more effective way to treat TNBC with the commonly used chemotherapy drug cyclophosphamide.
Your triple negative breast cancer FAQs:
How common is triple negative breast cancer?
In 2024 there were 2.4 million people around the world diagnosed with breast cancer making it the second most common cancer worldwide. on average about 15-20% of cases are triple-negative breast cancer, although the rate is higher in certain countries and populations.
Is triple negative breast cancer the most aggressive type of breast cancer?
Triple negative breast cancer is particularly aggressive, it can grow and spread quickly and can be challenging to treat. That's why research is particularly needed to find new ways to prevent, diagnose and treat this deadly cancer.
Prognosis does vary patient to patient though so if you or a loved one have been diagnosed with TNBC please speak to your oncology team about the best treatment plan for your individual cancer.
Can triple negative breast cancer be cured?
Like other cancers, the sooner TNBC is diagnosed the easier it is to cure. Some patients can be successfully treated, often with surgery, chemotherapy or radiotherapy. TNBC can spread quickly to other parts of the body though, making it much harder to cure. The more we understand about how TNBC spreads and how to stop it, the sooner we will reach a day where no life is cut short.
What is the survival rate of triple negative breast cancer?
Whilst other types of breast cancer have seen survival rates increase , TNBC is sadly lagging behind, Survival rates for TNBC vary in different countries, and depend a lot on the stage at which the disease is diagnosed. The estimated five-year survival rate can be as high as 92% for early stage cases but only 15% for late stage TNBC.
Why haven't survival rates for triple negative breast cancer improved?
When a breast cancer is diagnosed doctors look for 3 main things that they can target with treatment. TNBC cells do not have any of these 3 targets, so this type of cancer does not respond as well to the usual sort of treatments used.
To improve survival rates we need to understand new, different ways to target TNBC cells. Thanks to Curestarters Dr Klaus Pors is exploring a potential new target, and this research could lead to new cures and more precious time for patients.
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