In two studies, they identified 618 proteins linked to 19 different types of cancer, including 107 proteins in a group of people whose blood was collected at least seven years before diagnosis.

The research team discovered that the proteins could be involved at the very earliest stages of cancer, when the disease could be prevented.

The team believes the breakthrough could not only help treat the disease at an earlier stage, but even prevent it altogether.

They used a powerful technique called proteomics which allows them to analyze a large set of proteins in tissue samples at a single point in time, to see how they interact with each other—and find any important differences in proteins between different tissue samples.

In the first study, scientists analyzed blood samples taken from more than 44,000 British people, including more than 4,900 people who were subsequently diagnosed with cancer.

Using proteomics, the researchers analyzed a set of 1,463 proteins from a single sample of blood from each person. They compared the proteins of people who did and did not go on to be diagnosed with cancer to look for differences between them and find out which ones were linked to the disease risk.

The researchers also identified 182 proteins that differed in the blood three years before a cancer diagnosis took place.

In the second study, the team looked at genetic data from more than 300,000 cancer cases to do a "deep dive" into which blood proteins were involved in cancer development and could be targeted by new treatments.

They found 40 proteins in the blood that influenced someone's risk of getting nine different types of cancer.