Heidelberg researchers have developed a blood test to help in the early detection of breast cancer and presented first details of the method at a gynecological congress. Only a few milliliters of blood are needed for the procedure, according to Heidelberg University Hospital and Heiscreen. The test is expected to be released later this year.
The study identifies so-called biomarkers that suggest a cancer. According to a statement, the test can expand common diagnostic procedures such as mammography, ultrasound or MRI. First, the "Bild" newspaper reported on the process and celebrated it as "world sensation".
"Non-invasive and fast"
The blood test is "a new, revolutionary way to detect a cancer in the breast non-invasively and quickly using biomarkers in the blood," says Christof Sohn, medical director of the University Gynecological Clinic of Heidelberg and one of the developers of the process.
The test is a so-called liquid biopsy (liquid biopsy). Body fluids such as blood, urine or saliva are used to search for messenger substances or tumor cells in order to discover or characterize a cancer.
In a study in the past twelve months, the team around the medical son has examined more than 900 women - 500 of them with breast cancer. The accuracy of the new blood test for breast cancer patients was according to the announcement at 75 percent. Among the under 50-year-olds, the rate was 86 percent higher, for the over 50-year-olds, it is 60 percent lower. In the further course of the study, the use of the test for other types of cancer, such as ovarian cancer, should also be investigated.
Exciting approach, but many questions open
Klaus Pantel from Hamburger UKE is considered one of the pioneers of liquid biopsy. What does he think of the test now presented?
"That's certainly an exciting approach," says Pantel. But he is reluctant because the Heidelberg colleagues have presented their work so far only at a congress and there is no scientifically published study. According to the son, the Heidelberg have so far published for patent law reasons, no work, they want to catch up quickly.
For example, Pantel wonders how confident the test can be in early breast cancer. "Because we want to find the cancer then just then." It is also unclear whether all subgroups of breast cancer would be recognized equally well.
According to him, an examination with fewer than a thousand women is not enough to clarify all the important questions. "Other groups that develop similar tests usually test these with the help of several thousand subjects."
Even an average accuracy of the test of 75 percent is not optimal, according to Pantel. Because it means: In one out of four women with breast cancer, the test does not sound an alarm.
more on the subject
The Heidelberg researchers say that especially women under the age of 50 with a familial increased breast cancer risk could benefit from the test. Because at this age a mammography often does not provide a clear insight due to the dense mammary tissue.
Son himself says clearly: "We do not see ourselves as competition for mammography, but as a supplement." In addition, they have already tested the blood test in a total of about 2,000 women in various studies.
How often does the test provide the wrong alarm?
Also important is the question of how often the test provides a so-called false-positive result: how often he arouses the suspicion of cancer in women who have no breast cancer. Doctors also need to know exactly this indicator of a test because such suspected diagnoses lead to further examinations and can trigger considerable emotional stress for those affected. It should be clarified, for example, how to proceed if the test yields a positive result, but mammography shows no tumor, says Klaus Pantel.
"There are false-positive results in every test," says Christof Sohn. This would have to be able to circumvent medics. If in fact the blood test is positive and the imaging does not show a tumor, both tests should be repeated half a year later.
It is therefore premature at this time to speculate on whether the public health insurance funds take over the costs of the test and who exactly then would have a claim to it. First, other questions need to be clarified.
Currently, women in Germany aged 30 and above are entitled to a palpation examination of the breast for early detection of cancer. Women aged 50 to 69 are invited to mammography screening every two years. In Germany, around 70,000 women receive a breast cancer diagnosis each year. A good 70 percent of those affected are older than 54 years.