Scientists at the Wellcome Trust Sanger Institute, have unlocked the entire genetic code of two of the most common cancers - skin and lung.
The studies, published in the journal ‘Nature', of a malignant melanoma and a lung cancer, reveal for the first time almost all of the mutations in the genomes of two cancers. All cancers are caused by mutations in the DNA of cancer cells which are acquired during a person's lifetime.
Professor Mike Stratton, from the Cancer Genome Project at the Wellcome Trust Sanger Institute, said: "These are the two main cancers in the developed world for which we know the primary exposure. For lung cancer, it is cigarette smoke and for malignant melanoma it is exposure to sunlight.
"With these genome sequences, we have been able to explore deep into the past of each tumour, uncovering with remarkable clarity the imprints of these environmental mutagens on DNA, which occurred years before the tumour became apparent.
"We can also see the desperate attempts of our genome to defend itself against the damage wreaked by the chemicals in cigarette smoke or the damage from ultraviolet radiation. Our cells fight back furiously to repair the damage, but frequently lose that fight."
A complete genome catalogue for each patient would be expected to help select between treatments and to direct treatment in the most efficient and cost-effective way. The Sanger Institute is already working on a large scale project to tie genetic changes in cancers to their responses to anticancer treatments.
