The findings could lead to better diagnosis and treatments for cancer

A DNA analysis of thousands of tumours taken from NHS patients has shed new light on the genetic causes of cancer and could lead to new targets for treatment.

A team of researchers based at Cambridge University Hospitals and the University of Cambridge analysed the whole-genome sequences of more than 12,000 NHS cancer patients, studying the history of genetic mutations in each patient as the illness progressed.

Cancer cells, like these, contain DNA. DNA signatures in tumours can offer clues to the causes of the cancer

Thanks to the vast size of the data set they had to work with, the researchers were able to detect tell-tale patterns, or mutational signatures, in the DNA of each specific tumour that could provide clues to the patients’ past exposure to environmental causes of cancer such as smoking or UV light. They were also able to pin down 58 previously unidentified mutational signatures.

“The reason it is important to identify mutational signatures is because they are like fingerprints at a crime scene – they help to pinpoint cancer culprits,” said study leader Prof Serena Nik-Zainal, at the University of Cambridge. “Some mutational signatures have clinical or treatment implications – they can highlight abnormalities that may be targeted with specific drugs or may indicate a potential ‘Achilles heel’ in individual cancers.”

The genome data set was provided by the 100,000 Genomes Project, an England-wide clinical research initiative that has sequenced 100,000 whole genomes from more than 85,000 patients affected by rare diseases or cancer.

“With thousands of mutations per cancer, we have unprecedented power to look for commonalities and differences across NHS patients,” said the study’s first author Dr Andrea Degasperi, at the University of Cambridge.