Breast cancer genetic test is intended to prevent chemotherapy

Novel test procedure to prevent unnecessary chemotherapy in a variety of patients

03/28/2012

A pilot project of German breast cancer centers wants to spare patients with breast cancer onerous chemotherapy. An analytical gene test called „Oncotype DX“ should determine the risk of relapse and avoid chemotherapy after surgical removal of the breast tumor. A total of twelve clinics in the Rhineland and Hamburg offer this novel diagnostic procedure. However, the test is not undisputed.

In the context of chemotherapy, drugs are usually administered in the context of cancer therapy, the substances of which are intended to kill as well as possible disease-causing cells or to inhibit their growth. In this case, drugs with the group cytostatics are used. The treatment is usually associated with a good prognosis, depending on the case, but expect the patient sometimes severe side effects such as hair loss, diarrhea, nausea, vomiting, emotional exhaustion, mucosal inflammation and changes in the blood picture. About 75 percent of patients fall ill after chemotherapy at a special anemia. Depending on the type of medication, cardiovascular symptoms may also occur.

Pilot project with genetic test „Oncotype DX“
As a result, scientists and doctors are looking for alternatives to spare cancer patients the stressful treatment. A novel genetic test has already shown good results in numerous research projects. A total of twelve breast cancer centers in the Rhineland and Hamburg offer cancer patients suffering from breast cancer a pilot project to develop the gene test developed in the USA „Oncotype DX“ on. This should determine the risk of relapse. On the basis of the evaluation in the laboratory, it can be determined whether chemotherapy is necessary after the removal of the tumor.

According to the chief physician of the breast center Niederrhein, Prof. Ulrike Nitz, the test procedure in Germany is still „absolute new territory“. According to the doctor, the medical guidelines only recommend that the genetic test should be used in the course of student research. In about three to four years, an evaluation of the West German Study Group (WSG) is available. This should then report on the effectiveness of the gene process. Currently, the AOK Rheinland / Hamburg is taking over the costs of the test series. After all, the procedure costs about 3000 euros per patient. For comparison: The protein test used so far costs the coffers about 100 euros.

Aim: „50 percent of patients avoid chemotherapy“
Although risk tests are also available in Germany, unlike the frequently used uPA / PAI-1 protein test, the Genet Oncotype DX can provide information on several genes responsible for breast cancer, explained the scientific coordinator of the study group WSG, Oleg Gluz , In addition, Oncotype DX can also be used if the lymph nodes are affected in cancer patients. The declared goal of the experts is to increase the proportion of breast and female patients who can do without strenuous chemotherapy by 30 percent. Currently, a rate of 20 percent can be achieved through the protein test. With the new procedure, the physicians hope for a quota of 50 percent.

Breast cancer is among the cancers with the highest incidence of new disease. Each year around 57,000 women are newly diagnosed with breast cancer. More women die from breast cancer than from any other cancer. According to the German Robert Koch Institute, around 18,000 female patients die each year from breast cancer. Many women are very afraid of the rigors of chemotherapy. „The fear is in every head“ reports Nitz. More than 60 percent of women would not need chemotherapy because the risk profile for recurrence would be only medium or low.

Criticism: There is no evidence of the actual benefit
However, the new test is not undisputed. The renowned cancer specialist and head of the Breast Cancer Center at the Helios Clinic in Berlin-Buch, Prof. Michael Untch emphasized that the Oncotype DX is not recommended in the German guidelines, in contrast to the comparatively cheaper uPA / PAI-1 protein test. There is „No evidence that this test can prospectively save the patients chemotherapy“, criticized the doctor. The Hamburg and Rhineland breast centers would be one according to his words „stand-alone solution“ follow.

According to pharmaceutical manufacturer OncoDX examined „Expression and activity of a group of 21 genes, 16 cancer and 5 control genes.“ The results of the investigation will be followed by a so-called „Recurrence Score“. A numerical value between 0 and 100 indicates the risk of relapse and whether the patient requires chemotherapy in addition to hormonal therapy. Meanwhile, the genetic test since 2004, the US manufacturer „Genomic Health“ offered. The tests of the patients in Germany are evaluated within five days in the United States, said Nitz on Tuesday. Sent samples of tumor material are shipped. Fresh tissue, as in a uPA / PAI-1 test, according to experts is not necessary. Representatives of the West German study group emphasized that both test procedures are very different. In the uPA / PAI-1 test, the proportion of two proteins is determined. These are important indications of the presence of breast cancer. The Oncotype DX test examines the activity of 16 breast cancer genes and 5 reference genes. From both data, the risk of breast cancer recurrence is calculated.

First evaluations are available in 2015
According to current plans, the study is planned for 2015. For a year, the ethics committee in Cologne debated a two-stage diagnostic procedure. About 400 breast cancer patients from Hamburg and the Rhineland participate in the study. After the first evaluations, the patient population is to be expanded to around 4000 subjects. From this point on, about 80 breast centers throughout Germany will be involved in the study. In the US, the procedure has already been tested on around 12,000 patients. First results from the US-American test run, however, are only available in 2015. (Sb)

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