Genetic test in breast cancer: decision on chemotherapy remains difficult
Every year, around 75,000 women in Germany develop breast cancer. Breast cancer is the most common tumor among women in this country. Those affected usually have the question of whether chemotherapy is necessary. To answer this, biomarker tests are supposed to help. However, such genetic tests apparently do not provide clear insights.
Chemotherapy is not always useful
Around 75,000 women in Germany develop breast cancer every year. Many of them have to undergo chemotherapy with stressful side effects. But health experts have long been pointing out that this is not always useful for breast cancer.
No clear gain in knowledge
Biomarker tests are supposed to help you decide whether chemotherapy is necessary after breast cancer surgery. These can be used to measure the activity of genes in tumor tissue.
Such tests have been on the German market for years, in some cases the costs are borne by the health insurance companies.
In the coming year, the so-called Federal Joint Committee (G-BA) in Berlin wants to decide on a regulation for all legally insured women.
However, according to experts, such genetic tests currently do not bring any clear insight into the decision for or against chemotherapy.
Suitable for some patients
In its recently published new oncology guideline "Interdisciplinary S3 Guideline for Early Detection, Diagnostics, Therapy and Follow-Up Breast Cancer", the German Cancer Society also addresses genetic tests for doctors for the first time.
As Achim Wöckel, director of the women's clinic at the University Hospital Würzburg explained according to a message from the dpa news agency, these played an "increasingly important role" in addition to the classic prognostic factors.
"The guidelines advocate use in selected situations," said the expert.
Accordingly, such a test could be useful for patients in whom a reliable clinical decision on how to proceed after taking into account all other parameters and markers used as standard is not possible.
No clear benefit
However, the experts and organizations involved in the guideline came to a different conclusion than the Institute for Quality and Efficiency in Health Care (IQWiG) in Cologne.
According to the institute's report last year, which serves as the basis for the G-BA's decision on reimbursement, "none of the biomarker tests available at the time had any clue that it could better identify those women who do not need chemotherapy than the standard examinations “It says in a press release.
One cannot speak of a clear benefit of the examined test. On the one hand, the observation period of five years is too short: many distant metastases - i.e. metastases far from the affected breast - only appear in the following years.
"On the other hand, it is questionable whether one to two percent more deaths due to the recurrence and spread of cancer due to renouncing chemotherapy are really insignificant," wrote the institute last year.
Decision support for patients
Because studies are still pending for some tests, but the tests "are already widely used by gynecologists and oncologists and advertised by manufacturers", the G-BA commissioned the IQWiG to prepare a decision-making aid that has now been published.
This is aimed at women with early breast cancer, for whom there is no clear recommendation on whether they should undergo additional chemotherapy after the operation.
Because for around 20,000 patients in Germany each year, the conventional clinical-pathological criteria, such as the size of the tumor or the lymph status, provide a contradictory picture.
"The manufacturers of the biomarker tests promise to better recognize those patients who can do without chemotherapy," reports the institute.
This is by no means proven by meaningful studies. "The way in which the results of the biomarker tests are communicated easily reflects security that does not really exist," said the IQWiG.
Respond to uncertainties
According to the institute, user tests showed that the new brochure is able to convey the medical basics in an understandable manner.
"This also includes addressing the uncertainties," said Klaus Koch, head of the health information department responsible for the project at IQWiG.
"The women understandably want a clear statement as to whether a test makes sense or not," says Koch.
“Instead, they have to learn that there is no reliable scientific knowledge as to whether the new tests can actually predict their individual relapse risk more precisely. This situation, which is frustrating for some women, can at best only partially solve a written decision aid. "
Long-term examinations necessary
According to Wöckel, the reason for the different assessment in the new guideline and the IQWiG is that the institute did not take into account studies that were included in the evaluation for the guideline.
However, it also became clear there that widespread use was not considered useful and that other clinical parameters had to be considered first.
Wöckel also pointed out that the follow-up period was very short at five years. "Long-term examinations and studies with a large number of women are necessary," said the doctor, according to the dpa.
The S3 guideline also emphasizes: "It is important that all experts see an urgent need for research for the further investigation and clinical validation of gene expression tests."
One help among many
If a test indicates that there is no risk of recurrence or metastases and the cancer does return, the consequences for women are far greater than if chemotherapy had been through unnecessarily.
According to IQWiG, there are estimates that around two to three percent of chemotherapy leads to damage to the heart, kidneys or other internal organs, and even death.
In the dpa report, Wöckel also referred to the psyche as a factor: "Many women only really feel cancer when they undergo chemotherapy."
The treatment is not only associated with hair loss and fatigue, but also often with stigmatization by others. "In the long term, however, chemotherapy rarely hurts," says Wöckel.
According to him, patients are currently often very uncertain. "Some think that something is turned on with a test, others fear that something will be withheld without a test," said the director of the women's clinic at the University Hospital in Würzburg.
A lot of educational work is still needed. Neither the women affected nor the treating doctors should feel that a biomarker test is necessary to be able to make a good decision.
"This is clearly not the case," stressed the doctor, according to dpa. "Such a test can only be a contribution from many for a decision, help among many." (Ad)