ChaoticMusings

A 'Holy grail' blood test that can diagnose 50 types of cancer before symptoms appear begins trials with 140,000 Britons today. 

The Galleri test, which is currently available in the US, can detect cancers that are not routinely screened for and can pinpoint where in the body the disease is coming from with a high degree of accuracy.

Catching cancer early is vital to people receiving prompt treatment and the test has the potential to save thousands of lives in the UK every year.

It works by looking for chemical changes in fragments of genetic code - cell-free DNA (cfDNA) - that leak from tumours into the bloodstream.

Some cancer tumours are known to shed DNA into the blood a long time before a person would start experiencing symptoms.

The Galleri test does not detect all cancers and does not replace NHS screening programmes, such as those for breast, cervical and bowel cancer.

Scientists analysed how the test worked in 2,823 people with the disease and 1,254 people without.

It correctly identified cancer in 51.5% of cases, across all stages of the disease, and wrongly detected cancer in just 0.5% of cases.

When it came to solid tumours that are not currently screened for - such as oesophageal, liver and pancreatic cancers - the ability to generate a positive test result was twice as high (65.6%) as for solid tumours with screening options such as breast, bowel, cervical and prostate cancers.

When it came to blood cancers, around 55% of cases were detected, while the test correctly identified the tissue in which the cancer was located in the body in 88.7% of cases.

https://www.dailymail.co.uk/news/article-9984055