Breast cancer chemotherapy: genetic testing helps in the decision

After a breast cancer operation, many women also receive chemotherapy - in some cases, even if the tumor has been completely removed and the lymph nodes are not affected. This is to fight cancer cells, which may have spread in the body, and prevent relapses. The problem with this is that the doctors have been unable to predict which women will be saved from recurrence of the cancer by this "adjuvant" chemotherapy and which would have been cured without this treatment. The size of the tumor, its growth behavior, existing hormone receptors, and the patient's age helped the doctors to assess the risk.

That can change now. Recently, there are tests that more accurately characterize the tumor using gene and enzyme regulations. This makes it possible to determine the risk of relapse more accurately. And doctors can better decide if chemotherapy is really needed.

Some of these tests are already on the market, but not a single one is paid by the health insurance companies. Large studies have yet to show that, in effect, fewer women will die from breast cancer through the use of the new test. Patients who are still interested should contact their doctor, preferably before the tumor surgery.

New tests pretty much predict the risk of relapse

Quite accurately, a test designed to detect 70 different genes in breast cancer tissue (MammaPrint) predicts the risk of relapse. However, it has two serious disadvantages: it is very expensive (around 2500 euros) and can only be performed on fresh, unfixed tumor tissue. Frequently, however, the tumor is immediately placed during the operation for the pathological examination in a fixative solution. Women affected should therefore agree with the clinic before the procedure, so that the tumor tissue is not immediately fixed, but only deep-frozen.

A newer genetic test (Oncotype DX) can also be performed on fixed tissue. So far, however, it has been offered mainly in the US and in studies and is as expensive as the MammaPrint test.

The Femtelle test is more commonly used in Germany. It determines no genes, but special proteins (uPA and PAI-1) in the breast tissue, which are characteristic of the risk of relapse. One study found that more than half of the women who had a moderate risk of recurrence by conventional criteria could be included in a lower-risk group using the test - thus spared chemotherapy. Even with this test, which costs just under 200 euros, the tumor tissue must not be fixed.