A gene linked to triple negative breast cancer could point to a new targeted treatment, researchers say.
Triple negative breast cancer makes up about 15 per cent of breast cancer cases.
This form of the disease can be more aggressive and harder to treat than other types, with fewer targeted treatment options available.
It is also more common in women with an inherited altered BRCA gene, women under 40 and Black women.
The gene, called HORMAD1, is usually active only in reproductive cells in the ovaries and testes and stays switched off in the rest of the body.
It helps ensure genetic information is distributed properly in sperm and eggs.
But in some cancers, including 60 per cent of triple negative breast cancers, HORMAD1 becomes active where it should not be. Researchers at the Breast Cancer Now Toby Robins Research Centre at The Institute of Cancer Research, London, and the Breast Cancer Now Research Unit at King’s College London found that this disrupts a key safety mechanism in cells, causing errors in DNA to be passed on to new cancer cells.
While those changes can help cancer grow and resist treatment, the researchers said they also create a weakness that could be targeted with new therapies.
The study identified several drugs already being investigated as cancer treatments that may work against triple negative breast cancer cells with an active HORMAD1 gene. The team tested whether blocking three specific proteins, Aurora B, MPS1 and BUB1, could stop the growth of cells with the active gene in the laboratory.
They also tested whether two Aurora B inhibitors, currently in early-stage clinical trials, could treat mice carrying human triple negative breast cancer tumours with the active HORMAD1 gene. The treatment reduced tumour growth. The researchers said they will now investigate whether drugs targeting Aurora B, MPS1 and BUB1 could be developed for patients with this type of breast and possibly other cancers.
Professor Andrew Tutt, director of the Breast Cancer Now Toby Robins Research Centre at The Institute of Cancer Research, London, and the Breast Cancer Now Research Unit at King’s College London, and corresponding author of the study, said:
“Although this research is still in its early stages, it offers an important step forward in understanding triple negative breast cancer and opens the door for the development of new treatments. It also highlights that testing for the activity of the HORMAD1 gene in triple negative breast cancer could guide treatment decisions in the future. Together, these insights bring us closer to developing more precise therapies for people with triple negative breast cancer.”
Dr Simon Vincent, chief scientific officer at Breast Cancer Now, which funded the research, said:
“Each year, around 8,000 UK women are diagnosed with triple negative breast cancer and it’s more likely than most other breast cancers to return or spread during the first years following treatment. There are also fewer targeted treatments available, so it’s vital we find new and effective ways to tackle this devastating disease. The findings open the door to the next crucial phase of research, where the research team can identify and test the most effective drugs or drug combinations against triple negative breast cancer with an active HORMAD1 gene, and move the safest and most promising options towards clinical trials.”
Liz Boughton, 50, an NHS finance manager from Northamptonshire, was diagnosed with triple negative breast cancer in August 2024. She said:
“In July 2024, I accidentally brushed my arm against my breast and felt a very small lump. I dismissed it until I was persuaded by my husband to make an appointment with my doctor. I was quickly referred to the breast clinic, where a whirlwind of tests led to a diagnosis of triple negative breast cancer. I was 49, healthy, with no family history. Cancer wasn’t something I expected to hear.”
“I began 6 months of neo-adjuvant chemotherapy immediately, to shrink the tumour before surgery. I was also given immunotherapy (weekly) alongside the chemotherapy, a new treatment option for some people with triple negative breast cancer, which can improve outcomes. Once treatment began, it pulled me, and those around me, into a world we never knew existed. I then underwent surgery, followed by radiotherapy and a further 9 infusions of immunotherapy over 27 weeks.”
“When you’re diagnosed with a type of breast cancer that has fewer treatment options and a higher risk of returning soon after diagnosis, it’s hard not to live with constant uncertainty about the future. It can feel like you’ve been given a life sentence, but with continued research comes hope.”