Researchers at the University of Cambridge haves developed a new algorithm that could help personalise cancer treatment to pinpoint tumours.

A group of scientists, led by Professor Serena Nik-Zainal at the University’s Early Cancer Institute and the Cambridge Biomedical Research Centre, have created a new diagnostic tool, dubbed PRRDetect. This identifies tumours with specific DNA repair faults that make them more likely to respond to immunotherapy.

The team used the full genome sequences of 4,775 tumours from seven cancer types to train the tool to detect a DNA repair fault known as post-replicative repair dysfunction (PRRd).

“This kind of fault means the tumour is less able to fix its own DNA, and that makes it more vulnerable to certain treatments,” Nik-Zainal said, adding that “PRRDetect helps us spot those cases much more accurately.”

The research, published in Nature Genetics, found 37 distinct patterns of indel mutations. Eight were associated with PRRd, while others could be caused by environmental factors such as smoking. Nineteen remain unexplained.

Cancer types included in the study ranged from bowel and lung to skin, bladder and endometrial tumours. Several of these, in particular brain and lung cancer, typically have poorer survival rates.

The study was funded by Cancer Research UK (CRUK) and the National Institute for Health and Care Research. Chief Scientific Officer at Genomics England, Professor Matt Brown called the algorithm “a showcase of how sequencing data can drive better outcomes for patients.”

Nik-Zainal added: “We’re getting closer to a future where sequencing your tumour is as routine as a scan or blood test.”

In October last year, CRUK invested £173m in its institute at the University of Cambridge. This is the largest grant ever to be awarded by CRUK outside of London.