A “groundbreaking” development in cancer research could make some of the most common types of cancer much easier to detect. Researchers have discovered that a new blood test could help to diagnose cancer in its early stages, and may even be able to identify the exact location of the tumour in the body. This could be used on patients to diagnose common types of cancer, including stomach, liver, pancreas, lung, oesophagus, breast and ovary, in a much less invasive way than other tests. In addition to this, the blood test, which is known as CancerSEEK, is estimated to cost less than $500, which is similar to other commonly used screening tests.
“The success rate of therapeutics and surgeries is going to be much, much higher, we believe, if the cancer is found very early, before symptoms,” said Dr. Nickolas Papadopoulos, professor of oncology and pathology at Johns Hopkins Medicine and senior author of the study. He added that “The results are good enough to warrant the next step, which is to test this in a screening setting, meaning in thousands of individuals that actually do not have cancer and see really how well our test works.”
Dr. Martin Widschwendter, a professor and head of the department of women’s cancer at University College London, who was not involved in the new study, said that this new discovery could be groundbreaking. “All these different components in isolation have been demonstrated in the past for individual cancers. The groundbreaking nature is that blood protein markers have been combined with DNA markers and analysed in a set of individuals with various cancers and controls,” he said.
As part of the study, researchers looked at the levels of eight different proteins in the human body, and combined with the presence of any mutations, this information was used to identify any signs of cancer in the blood. When tested on patients, it was found to accurately detect an estimated 70% of cancers. However, the results did vary between cancer types, with a 98% success rate for ovarian cancer but only 33% for breast cancer, which is more common.
The researchers were able to find the specific location of tumours in 63% of the patients. “We were pleasantly surprised that we could detect the amount of cancers that we were able to detect,” Papadopoulos said. “We were even more pleasantly surprised that not only we detected cancers, but with some degree of certainty, we were able to localize it to at least two sites as to where these cancers might be.”
Despite the positive results seen in the study, the researchers noted that further research would need to be carried out before it was rolled out to patients and that it only “lays the conceptual and practical foundation” for the test. Mangesh Thorat, deputy director of the Barts Clinical Trials Unit at the Center for Cancer Prevention at Queen Mary University of London who was not involved in the study also commented that “This is only a case-control study, and therefore needs further evaluation in large cohorts more representative of (the) general population.”
He added “The sensitivity of the test in stage I cancer is quite low, about 40%, and even with stage I and II combined it appears to be around 60%. So the test will still miss a large proportion of cancers at the stage where we want to diagnose them. The proportion of common cancers — breast, lung, colorectal — detected is again not as high as other, rarer cancers. This may mean that a screening program has to test a very large number of individuals to detect one cancer. There is a lot more work to be done before a blood test can be offered for early diagnosis of a combination of various cancers,” he said. “There is a long way to go before we can actually do this.”