Cancer is one of the leading causes of death worldwide, but many cancers can be cured if they are diagnosed and treated early. However, some of the most common and lethal cancers, such as ovarian and gastroesophageal cancers, often have no symptoms until they are advanced and difficult to treat. That is why there is an urgent need for a simple and reliable blood test that can screen for these cancers before they cause any harm.

A team of researchers from the University of Cambridge has developed such a test, called CancerSEEK. The test works by measuring the levels of eight proteins and the presence of mutations in 16 genes in the blood. These proteins and genes are known to be associated with cancer development and progression. By combining these biomarkers, the test can detect the presence of cancer cells in the blood and also indicate the type and location of the tumor.

The researchers tested CancerSEEK on more than 1,000 patients who had no symptoms but were diagnosed with one of eight common cancers: ovarian, liver, stomach, pancreas, esophagus, colorectum, lung or breast. The test was able to identify 70% of the cancers, with a specificity of 99%. This means that the test had a very low rate of false positives, which is important to avoid unnecessary anxiety and further tests. The test was also able to correctly identify the organ or tissue where the cancer originated in 83% of the cases.

The researchers hope that CancerSEEK could be used as a screening tool for high-risk populations, such as people with a family history of cancer or those who have certain genetic mutations. The test could also be used to monitor the response to treatment and the recurrence of cancer after surgery or chemotherapy. The researchers estimate that the cost of the test could be less than $500 per person, which is comparable to other screening tests such as colonoscopy.

The results of the study were published in the journal Science and have been hailed as a breakthrough in cancer detection. The researchers plan to conduct larger trials with more participants and more types of cancers to validate and improve the test. They also aim to make the test more sensitive and specific by adding more biomarkers and using machine learning algorithms. Ultimately, they hope that CancerSEEK could save millions of lives by detecting deadly cancers sooner.