Cambridge and London researchers have created a database of DNA mutation “fingerprints” which can be used to determine the environmental factors contributing to a patient’s tumour. The study, published in Cell journal, can determine 41 different environmental agents linked to cancer, including the traces left in lung tumours by chemicals linked specifically to tobacco smoke.

In the study, induced pluripotent stem cells were exposed to 79 known or suspected environmental carcinogens. WGS was then used to look at the changes caused by, with 41 of the suspected carcinogens leaving a unique fingerprint on the DNA of the stem cells.

While some of the tested elements were known carcinogens, such as sunlight or polycyclic hydrocarbons, others were uniquely discovered, with individual chemicals in tobacco smoke studied for the first time and found to cause signatures very similar to those found in smokers’ lung cancer.

Certain fingerprints caused by chemotherapy drugs, dietary chemicals and diesel exhaust fumes were also discovered.  

Dr Serena Nik-Zainal, working for the Department of Medical Genetics and MRC Cancer Unit at the University of Cambridge, noted that: “Our reference library will allow doctors in future to identify those culprits responsible for causing cancer…such information could be invaluable in helping inform measures to reduce people’s exposure to potentially dangerous carcinogens.”