Novel blood test detects eight cancers

In  1,005 patients with stage I-III cancers, CancerSEEK showed a sensitivity of 33% (breast cancer) to 98% (ovarian cancer). The assay detects a 16 typical mutations as well as eight cancer proteins which together point to eight solid tumour types (cancers of the ovary, liver, stomach, pancreas, esophagus, colorectum, lung or breast) causing 60% of all US cancer deaths. The authors believe that their liquid biospy screening assay might open the way to early disease detection, before the primary tumour has spread to other organs.

According to the authors, keeping the mutation panel small was essential to minimise false-positive results and keep a screening test affordable. In fact, the test showed a specifity of 99%, meaning that only one in hundred  healthy individuals receive a false positive result. Using the test on 812 healthy controls, Cancer SEEK produced only seven false-positive results.

In some cases, the test also provided information about the tissue-of-origin of the cancer. Using machine learning, the researchers enabled the test to accurately determine the location of a tumour down to a small number of anatomic sites in 83% of patients. The researchers estimate that the cost of this single blood test for eight cancer types may be less than US$500, which is comparable to or lower than screening tests such as colonoscopy. Larger studies of the test are currently under way.