The Mutations That Kill: 1st Cancer Genomes Decoded
The scientists say they have pinpointed specific DNA errors that may cause tumors in these two cancers, both of which have direct known causes—smoking for lung cancer and sun exposure for skin cancer. Researchers predict these maps will offer patients a personalized treatment option that ranges from earlier detection to the types of medication used to treat cancer. The genetic maps will also allow cancer researchers to study cells with defective DNA and produce more powerful drugs to fight the errors, according to the the study’s scientists [CNN]. News reports are heralding the new research as revolutionary, however it will be years, perhaps decades, before the full implications of the work are understood.
The lung cancer and skin cancer studies, which were published in the journal Nature, found the DNA code for a skin cancer called melanoma contained more than 30,000 errors almost entirely caused by too much sun exposure. The lung cancer DNA code had more than 23,000 errors largely triggered by cigarette smoke exposure [BBC News]. The bullet point grabbing most headlines is that the scientists say for every 15 cigarettes a person smokes, they acquire a new mutation in their DNA. Not all of those mutations will be in areas of a person’s DNA related to cancer, but some will.
According to Mike Stratton, of the Cancer Genome Project at the Wellcome Trust Sanger Institute, “these catalogues of mutations are telling us about how the cancer has developed, so they will inform us on prevention. They tell us about all the processes which are disrupted in cancer cells, which we can try to influence through our treatments. So this is a really fundamental moment in the history of cancer research. I can envisage a time a decade or more hence when these catalogues will become routine, and influential in selecting treatment for that individual. That’s what we’re expecting—every cancer patient will have one of these charts” [London Times]. However, just because scientists now possess this genetic information, it doesn’t necessarily mean a cure for cancer is around the corner. The sequencing of the human genome almost 10 years ago had many researchers giddy about the possibility of personalized medicine and gene therapy, but it’s been much harder to translate the genomic data into treatments than many anticipated.
The study is a part of the International Cancer Genome Consortium, which involves countries around the world working on similar cancer-genome-sequencing projects. The UK is looking at breast cancer; the U.S. at brain, ovary, and pancreatic cancer; China at stomach cancer; Japan at the liver; and India at mouth cancer. The completion of all this work is at least five years—and several hundreds of thousand dollars—into the future, say the researchers.