In the most extensive study of its kind, a team of scientists led by Professor Serena Nik-Zainal from Cambridge University Hospitals (CUH) and the University of Cambridge analyzed the complete genetic makeup or whole-genome sequences (WGS) of more than 12,000 NHS cancer patients.
Immunofluorescent staining of Merkel cell carcinoma tumor tissue illustrating expression of CD200 (green) on the surface of tumor cells. CD200 plays a role in immunosuppression. The endothelial marker CD31 (red) highlights blood vessels. Merkel cell carcinoma is a rare and aggressive skin cancer. Credit: Isaac Brownell, National Institute of Arthritis and Musculoskeletal and Skin Diseases/NIH via Flickr, Public Domain
Because of the vast amount of data provided by whole genome sequencing, the researchers were able to detect patterns in the DNA of cancer, known as ‘mutational signatures,’ that offer clues about whether a patient has had past exposure to environmental causes of cancer such as smoking or UV light, or has internal, cellular malfunctions.
The team was also able to spot 58 new mutational signatures, suggesting that there are additional causes of cancer that we don't yet fully understand. The results are reported in the journal Science.
The 100,000 Genomes Project provided the genomic data: an England-wide clinical research initiative to sequence 100,000 whole genomes from around 85,000 patients affected by rare diseases or cancer.
“WGS gives us a total picture of all the mutations that have contributed to each person’s cancer,” said first author Dr. Andrea Degasperi from Cambridge’s Department of Oncology. “With thousands of mutations per cancer, we have unprecedented power to look for commonalities and differences across NHS patients. In doing so, we uncovered 58 new mutational signatures and broadened our knowledge of cancer.”
“It is important to identify mutational signatures because they are like fingerprints at a crime scene – they help pinpoint cancer culprits,” said Serena Nik-Zainal, from the Department of Medical Genetics and an honorary consultant in clinical genetics at CUH. “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.
“We were able to perform a forensic analysis of over 12,000 NHS cancer genomes thanks to the generous contribution of samples from patients and clinicians throughout England. We have also created FitMS, a computer-based tool to help scientists and clinicians identify old and new mutational signatures in cancer patients, to inform cancer management potentially.”
Michelle Mitchell, chief executive of Cancer Research UK, which funded the research, said:
“This study shows how powerful whole genome sequencing tests can be in giving clues into how cancer may have developed, how it will behave, and what treatment options would work best. It is fantastic that insight gained through the NHS 100,000 Genomes Project can potentially be used within the NHS to improve the treatment and care for people with cancer.”
Professor Matt Brown, chief scientific officer of Genomics England, said:
“Mutational signatures are an example of using the full potential of WGS. We hope to use the mutational clues seen in this study and apply them back into our patient population to improve diagnosis and management of cancer patients.”
Professor Dame Sue Hill, chief scientific officer for England and Senior Responsible Officer for Genomics in the NHS, said:
“The NHS contribution to the 100,000 Genomes Project was vital to this research and highlighted how data can transform the care we deliver to patients, a cornerstone of the NHS Genomic Medicine Service.”
Source: Cambridge University