血检可以测出肿瘤的生长位置
A blood test for cancer can now show where in the body a tumour is growing, without the need for a painful biopsy.
一种癌症的血液检测方法可以测出肿瘤在体内生长的位置，而不需要进行活组织检测。
'Liquid biopsies' are hoped to revolutionise cancer treatment, by identifying people with slow-growing tumours and those most in danger. They work by detecting the DNA released by dying tumour cells.
Now, for the first time, US scientists can also pinpoint the part of the body affected.
That is because the normal cells killed off by cancer also release DNA into the bloodstream, which has its own unique signature.
A team from the University of California San Diego have found the DNA patterns for 10 different types of tissue, including from the liver, lung and kidneys.
It means cancer patients who have symptoms shared across different types of cancer, such as bloating or sudden weight loss, could in future be diagnosed quickly and easily without needing a biopsy to remove part of an organ for testing.
Dr Catherine Pickworth, Cancer Research UK's science information officer, said: 'A biopsy can be invasive and unpleasant to go through, while any operation with an anaesthetic is risky.
This is potentially safer if it can be effective, which is why people are focusing on liquid biopsies.