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Breast cancer: genetic test to prevent chemotherapy

Breast cancer: genetic test to prevent chemotherapy

Novel test procedure is designed to prevent unnecessary chemotherapy in a large number of patients

A pilot project by German breast cancer centers aims to save breast cancer patients from chemotherapy. An analytical genetic test called "Oncotype DX" is intended to determine the risk of relapse and to save chemotherapy after surgical removal of the breast tumor. A total of twelve clinics in the Rhineland and Hamburg offer the new diagnostic procedure. However, the test is not without controversy.

With chemotherapy, drugs are usually administered as part of cancer therapy, the substances of which are intended to kill disease-causing cells as specifically as possible or to inhibit their growth. Pharmaceutical substances with the cytostatics group are used. Depending on the case, the treatment is usually associated with a good prognosis, but the patient can expect severe side effects such as hair loss, diarrhea, nausea, vomiting, emotional fatigue, inflammation of the mucous membranes and changes in the blood count. Around 75 percent of patients develop special anemia after chemotherapy. Depending on the type of medication, cardiovascular symptoms can also occur.

Pilot project with genetic test "Oncotype DX"
As a result, scientists and doctors are looking for alternatives to save cancer patients from 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 who developed breast cancer the “Oncotype DX” genetic test developed in the USA as part of a pilot project. This should determine the risk of relapse. Based on the evaluation in the laboratory, it can be determined whether chemotherapy is necessary after the tumor has been removed.

According to the chief physician of the Lower Rhine Breast Center, Prof. Ulrike Nitz, the test procedure in Germany is still “completely new territory”. According to the doctor, the medical guidelines have so far only recommended that the genetic test be used in the course of study work. An evaluation of the West German Study Group (WSG) should be available in a good three to four years. This should then report on the effectiveness of the genetic process. AOK Rheinland / Hamburg is currently covering the costs of the test series. After all, the procedure costs around 3000 euros per patient. For comparison: the protein test used so far costs the cash registers around 100 euros.

Goal: "Save 50 percent of patients from chemotherapy"
Although risk tests also exist in Germany, in contrast to the commonly used uPA / PAI-1 protein test, the Oncotype DX genetic test can provide information on several genes that are responsible for breast cancer, explained the scientific coordinator of the WSG study group, Oleg Gluz . In addition, Oncotype DX can also be used if the lymph nodes in cancer patients are affected. The experts' stated goal is to increase the proportion of breast patients who can do without strenuous chemotherapy by 30 percent. The protein test can currently achieve a rate of 20 percent. With the new procedure, doctors hope for a quota of 50 percent.

Breast cancer is one of the cancers with the highest rate of new cases. Every year, around 57,000 women develop breast cancer. Breast cancer kills more women than any other cancer. According to the German Robert Koch Institute, around 18,000 breast cancer patients die each year. Many women are very afraid of the hardships of chemotherapy. "Fear is in every head," reports Nitz. Over 60 percent of women would not need chemotherapy because the risk profile for recurrence would only be in the medium or low range.

Criticism: There is no evidence of the actual benefit
However, the new test is not without controversy. 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 uPA / PAI-1 protein test, which is comparatively cheaper at 100 euros. There is “no evidence that this test can be used prospectively to save the patient chemotherapy,” criticized the doctor. The Hamburg and Rhineland breast centers would, in his words, pursue an "island solution".

According to the pharmaceutical manufacturer, OncoDX is investigating "the expression and activity of a group of 21 genes, 16 cancer genes and five control genes." The results of the investigation subsequently result in a so-called "recurrence score". A numerical value between 0 and 100 indicates the risk of relapse and whether the patient needs chemotherapy in addition to hormonal therapy. The genetic test has now been offered by the US manufacturer “Genomic Health” since 2004. Patients' tests in Germany will be evaluated within five days in the United States, said Nitz on Tuesday. Preserved samples of tumor material are dispatched. According to experts, fresh tissue, like a uPA / PAI-1 test, is not necessary. Representatives of the West German study group emphasized that the two test procedures are very different. In the uPA / PAI-1 test, the proportion of two proteins is determined. These are important indicators of the presence of breast cancer. The Oncotype DX test examines the activity of 16 breast cancer genes and 5 reference genes. The breast cancer relapse risk is then calculated from the two data obtained.

The first evaluations will be available in 2015
According to current plans, the study is scheduled to run until 2015. For a year, a two-stage diagnostic procedure was discussed with the ethics committee in Cologne. Around 400 breast cancer patients from Hamburg and the Rhineland are participating in the study. After the first evaluations, the patient group is to be expanded to around 4000 subjects. From this point on, around 80 breast centers throughout Germany will be involved in the study. The procedure has already been tested on around 12,000 patients in the USA. However, the first results from the US test run will not be available until 2015. (sb)

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Author and source information

Video: Genetic Breast Cancer Test Helps Some Patients Avoid Chemo (October 2020).