Can this simple blood test detect cancer before the first symptoms appear?

Can this simple blood test detect cancer before the first symptoms appear?

A few days ago, scientists at Johns Hopkins School of Medicine in Baltimore published findings from research into CancerSEEK. This test aims to detect cancer using a blood sample.

CancerSEEK looks for the presence of eight different types of cancer: lung, colorectal, liver, ovarian, stomach, pancreatic, oesophageal and breast cancer. These cancers account for more than 60 per cent of cancer deaths in the United States.

Scientists took blood samples from more than 1000 people with one of eight different types of cancer, and CancerSEEK identified tumours in 70 per cent of those tested. These success rates ranged from 98 per cent (in patients with ovarian cancer) to 33 per cent (in women with a breast tumour). The researchers are pleased with the tests carried out and believe that making progress in early cancer detection requires a more realistic approach. Professor of oncology Bert Vigelstein confidently states that no test can detect all cancers.

The scientists also carried out other studies using CancerSEEK. They tested 812 healthy people, of whom 7 tested positive. The result report is issued in Polish. However, the specialists pointed out that they were unsure whether these 7 positive results were genuine, whether the test had produced false positives, or whether the participants had early-stage cancer despite having no symptoms.

The frequency of false-positive results is considerably lower than with conventional screening tests used to detect specific cancers. Examples include mammography and screening for colon cancer. A major advantage of CancerSEEK is its price. The current price is shown on BadamySie.pl.

Scientists in Baltimore have been working for many years on a blood test known as a liquid biopsy, which may become an inexpensive, routine tool for diagnosing cancer in the near future, before the first symptoms of the disease appear. CancerSEEK focuses primarily on early cancer diagnosis, looking at just 16 DNA mutations typical of cancer in the blood, as well as 8 protein biomarkers. It is also worth noting that early screening tests are still unavailable for as many as five of the eight cancers investigated by CancerSEEK. So far, screening is available for breast cancer (mammography), cervical cancer (cervical cytology) and cancer of the prostate gland, or prostate cancer (prostate-specific antigen (PSA)).

It is worth knowing that even the most accurate X-rays can only detect a tumour once it reaches a certain size. Another advantage of CancerSEEK is therefore that, using only the patient’s blood, the test was able to identify the organ containing the tumour in as many as 63 per cent of participants, and narrow its location down to two organs in 83 per cent.

The fact is that many established cancers develop very slowly. It can take as long as 20,30 years for the full symptoms of cancer to appear. Unfortunately, by the time tumours are diagnosed, they may already have spread beyond the original tissue, making treatment extremely difficult. Cancers that have not invaded other organs or spread beyond the original tissue can be treated surgically. When metastases occur, treatment includes chemotherapy and radiotherapy.

Research into CancerSEEK has not been completed, and the scientists reiterate that trials should be conducted on a larger scale. Before the test is made commercially available, new studies will be carried out involving 10 thousand healthy people. The specialists hope that these studies will allow them to assess the test’s reliability further and answer the question of whether CancerSEEK can detect cancer earlier than currently available methods. The scientists also intend to continue improving the product.

Another stage of research into CancerSEEK has also begun, with a group of researchers from Geisinger Health System in Pennsylvania joining the Baltimore scientists. The study involves 50 thousand healthy women aged 65-75, and a very important question is whether the test will be able to identify patients who have cancer but do not know it.

Although the CancerSEEK test results are undoubtedly exciting, oncologists recommend restraint and caution until the ongoing studies are completed.