Scientists believe they are a step closer to developing vaccines for different types of cancer.
A team of international researchers, including scientists from the University of East Anglia (UEA), carried out the first comprehensive survey of viruses found within different types of cancer.
They hope their work will lead to new vaccines, similar to the human papillomavirus (HPV) vaccine, which could prevent the disease from developing.
Dr Daniel Brewer, from UEA’s Norwich Medical School, said: “We already knew of some strong associations between infections and cancer.
“This has given us a fantastic opportunity to collect data to find new associations between viruses and different types of cancer.
“This is the first time that a systematic study of the majority of cancer types for viruses has been made.
“It is important because finding new links between infection and cancer types has the potential to provide vaccines, such as the HPV vaccine, which could reduce the global impact of cancer.”
Scientists from around the world looked at the genetic material, or genome, of tumours, as part of the global Pan-Cancer Analysis of Whole Genomes project.
Their work involved creating the most comprehensive map on whole cancer genomes to date.
The team analysed and sequenced nearly 2,700 whole genomes of cancer samples and mapped mutations in 38 different types of tumours.
They discovered traces of 23 different virus types in 356 cancer patients.
The genome of Epstein-Barr viruses (EBV), known to cause cancers such as lymphoma, stomach cancer and nasopharyngeal cancer, was found in 5.5% of the cancer genomes investigated.
Hepatitis B virus (HBV) DNA was identified in 62 of the 330 cases of liver cancer.
The team also found human papillomaviruses, most commonly HPV16, in 19 of 20 cervical cancers cases and in 18 of 57 head and neck tumours.
Dr Marc Zapatka, from the German Cancer Research Centre (DKFZ), said: “The issue of which viruses are linked to cancer is highly relevant in medicine, because in virus-related cancers, real prevention is possible.
“If a carcinogenic virus is identified, there is a chance of avoiding infection with a vaccine to prevent cancer developing.”
The findings are published in the journal Nature Genetics.
The paper is one of a suite of more than 25 papers published in Nature and other Nature Research journals.