Triple-negative breast cancer – how we’re helping progress research
Worldwide Cancer Research funds research into all cancer types, but a significant number of the projects we fund are about breast cancer. Thanks to research that has led to more effective treatments, breast cancer survival has doubled in the last 40 years. Nowadays, around 8 in 10 women diagnosed with breast cancer will live for more than 10 years after diagnosis and many for much longer than that. This is good news for many women, but those diagnosed with triple-negative breast cancer are less fortunate.
Triple-negative breast cancer is a problem. It has the worst prognosis of all the forms of breast cancer, and the mainstay of treatment is still conventional chemotherapy. Scientists around the world recognise there is still a long way to go with triple-negative breast cancer, and we have noticed that we are receiving more and more applications for funding in this area.
Why such a poor prognosis?
There are a number of very effective breast cancer treatments. One example is tamoxifen, which prevents oestrogen from reaching oestrogen receptors on the surface of breast cancer cells and stimulating the cancer cells to grow. Drugs also exist against other cancer-fuelling receptors, such as the progesterone receptor and HER2 receptor.
But triple-negative breast cancer doesn’t have any receptors for oestrogen, progesterone or HER2, hence the name. This means triple- negative breast cancer is the hardest to treat. Only about 15 out of every 100 breast cancers are triple-negative.
"Triple-negative breast cancer tumours do not express any of the hormone receptors targeted by the mainstay hormonal therapies like tamoxifen," says Professor David Vaux at the Walter and Eliza Hall Institute of Medical Research in Australia. "Often, chemotherapy can be the only option for these patients."
How are we helping?
A key challenge of developing new breast cancer treatments is not only to identify new drugs that are effective and have fewer side effects, but also to match them with the type of breast cancer that will respond - this can be a stumbling block for triple-negative breast cancer.
However, Professor Vaux and his team have gathered exciting early data, which suggests that a new type of targeted drug called birinapant might work well, and they are continuing this research with our funding. Professor Vaux explains: "In this project we want to confirm our earlier birinapant results by using a special mouse model implanted with tumour tissue taken from women with (triple-negative) breast cancer. We will also test the combination of birinapant with other drugs, to optimise its effectiveness. It's really exciting - if our work is successful, these results will provide the basis for a clinical trial." And Professor Miguel del Pozo is trying to find new drugs to treat triple-negative breast cancer. He is studying the tools that breast cancer cells use to communicate with their environment. His aim is to identify the mechanisms that cause this environment to ‘stiffen’, and to discover drugs that can prevent it.
Another way to control triple-negative breast cancer could be to stop it spreading to other parts of the body. The risk of this happening in triple-negative breast cancer is especially high because the growth of the breast tumour is less likely to be stopped by first-line treatments. Work like that of Professor Clare Isacke, who is looking to find new ways of treating secondary breast cancer, or Professor Mike Olson, who is investigating ways to stop cancer tumours from spreading, could be of particular benefit to triple-negative breast cancer patients.
You can find out more about the type of breast cancer research we are funding here.
In the pipeline
We haven’t just started funding research on triple-negative breast cancer. Back in 2008, we funded Dr Karen Blyth at the Beaston Institute in Glasgow. Her lab is studying the RUNX2 gene. RUNX2 is a one of a family of genes that are involved the growth of our bodies in early development. When it is active in the correct way, RUNX2 is important in the growth of our skeleton. However, Dr Blyth found that it is highly active in triple-negative breast cancer too, but working in an unexpected (abnormal) way. And patients whose tumours had highly active RUNX2 genes had lower chance of survival than those with little or no RUNX2. Further research is needed to find out what role RUNX2 is playing in cancer development, but these results point towards the possibility of using RUNX2 to diagnose triple-negative cancer patients, and treating them accordingly.
And, based on early work that we funded in 2006, Dr David Meek at the University of Dundee, has since identified a possible new way to treat triple-negative breast cancer, using a drug that has shown promising results in the lab and is currently being tested for other cancer types, such pancreatic cancer and lymphoma. We hope that this drug will one day be tested in women with triple-negative breast cancer too.
You may also have read our post a few months ago, which describes research that found cheap drugs used to treat parasitic worms and conditions such as river blindness could be used to treat triple-negative breast cancer.
All of this research is still in the testing pipeline and there is a way to go before it can help women diagnosed with the disease. However, we hope that at least some of it will go on to extend the lives of women with triple-negative breast cancer in the future.
If you want to help support this much-needed research into triple-negative breast cancer, please text WORLDWIDE to 70004 to donate £10.
Photo credit: Professor Miguel del Pozo, CNIC, Spain
Photo caption: Breast cancer cells (magenta) are grown with fibroblasts (green) - cells that are involved in maintaining the structure of tissues within our bodies, and in cancers, making the surrounding tissue 'stiffer.' His lab has made a lentivirus (red), which stops one of the genes in the fibroblasts from working. They are using this system to study how tumours grow and spread.
Written by Dr Gwen Wathne and Dr Helen Rippon