Researchers at the Breast Cancer Now Toby Robins Research Centre at The Institute of Cancer Research, London have uncovered a hidden weakness in some tumours that could lead to smarter treatment decisions.
In this section
When all is not as it seems
One of the body’s natural defences against cancer is a gene called RB1. This complex gene is involved in many processes that keep cells healthy. It also helps control how quickly cells grow and divide.
When this gene is altered or missing, which happens in many different types of cancer, this is generally associated with an aggressive form of cancer.
Now, Dr Syed Haider and Professor Chris Lord’s teams have shown that some breast cancers behave as if RB1 is altered, even when standard tests show it isn’t. This hidden pattern has been named ‘RBness’.
From data to discovery
To understand this hidden pattern, our researchers analysed over 1000 breast tumour samples. And by comparing cancers with and without RB1 alterations, the researchers noticed something unusual.
Many tumours that looked normal under standard genetic tests were behaving just like RB1-defective cancers. These were the RBness cases — and they were more common than expected.
Why this discovery could change treatment
Cancers with RBness are linked to poorer outcomes and associated with more aggressive cancer subtypes such as triple negative breast cancer. But these cancers also showed strong responses to chemotherapy — just like tumours with a clear alteration in the RB1 gene.
However, the same RBness pattern was linked to lower responses to CDK4/6 inhibitors — a targeted treatment used in some types of breast cancer. This means spotting RBness could help tailor treatments more effectively, offering chemotherapy where it’s likely to help, and avoiding treatments that may not.
The researchers also found that RBness cancers share many of the same weaknesses as those with altered RB1 genes.
This means that drugs that are developed to target weaknesses in RB1-altered tumours could potentially also work in cancers with RBness — opening the door to new treatment options in the future.
What’s next?
This discovery opens up exciting new possibilities for improving how we treat breast cancer, but more work is needed to bring it into clinical practice. The researchers now hope to validate these findings in larger, real-world clinical studies.
Ultimately, this research brings us one step closer to truly personalised breast cancer treatment — where each person gets the treatment that’s most likely to work for them.
25 years of discoveries
This finding is the latest of 25 years of ground-breaking discoveries at our research centre. Each one taking us closer to our vision that by 2050, everyone diagnosed with breast cancer will live, and be supported to live well.