科学家破解癌症“全部基因组”

Scientists have unlocked the entire genetic code of two of the most common cancers - skin and lung - a move they say could revolutionise cancer care.

科学家成功破解最常见癌症之中的皮肤癌和肺癌的全部的基因组，他们称这将使癌症治疗革命性变化。

Not only will the cancer maps pave the way for blood tests to spot认出 tumours far earlier, they will also yield new drug targets, says the Wellcome Trust team.

Scientists around the globe are now working to catalogue all the genes that go wrong in many types of human cancer.

The UK is looking at breast cancer, Japan at liver and India at mouth.

China is studying stomach cancer, and the US is looking at cancers of the brain, ovary子房，卵巢 and pancreas胰腺.

The International Cancer Genome Consortium scientists from the 10 countries involved say it will take them at least five years and many hundreds of thousands of dollars to complete this mammoth巨大的，庞大的 task.

But once they have done this, patients will reap the benefits.

Professor Michael Stratton, who is the UK lead, said: "These catalogues are going to change the way we think about individual cancers.

"By identifying all the cancer genes we will be able to develop new drugs that target the specific mutated genes and work out which patients will benefit from these novel treatments.

"We can envisage面对，想象 a time when following the removal of a cancer cataloguing it will become routine."

It could even be possible to develop MoT-style blood tests for healthy adults that can check for tell-tale登记机，试片 DNA patterns suggestive of cancer.

Russian roulette

The scientists found the DNA code for a skin cancer called melanoma黑素瘤 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.

From this, the experts estimate a typical smoker acquires one new mutation for every 15 cigarettes they smoke.

Although many of these mutations will be harmless, some will trigger cancer.

Wellcome Trust researcher Dr Peter Campbell, who conducted this research, published in the journal Nature, said: "It's like playing Russian roulette俄罗斯轮盘.

"Most of the time the mutations will land in innocent parts of the genome, but some will hit the right targets for cancer."

By quitting smoking, people could reduce their cancer risk back down to "normal" with time, he said.

The suspicion is lung cells containing mutations are eventually replaced with new ones free of genetic errors.

By studying the cancer catalogues in detail, the scientists say it should be possible to find exactly which lifestyle and environmental factors trigger different tumours.