Use of prognostic gene expression profiling tests in primary breast cancer treatment: a German real-world patient...

Aims: In primary breast cancer, gene expression profiling tests can support adjuvant chemotherapy treatment decisions. Real-world test use in Germany was investigated in an online survey of female breast cancer patients (n = 475). Materials & methods: Relationships between three groups were examined for clinical and statistical relevance: no test indication (n = 353), test indication and tested (n = 65), and test indication but not tested (n = 57). Results: A total of 47% of participants with a test indication were not tested. Test rates increased by 23% from 2012-2018 (49%) to 2019-2021 (60%). A total of 65% of patients without testing received chemotherapy, whereas only 38% of tested patients received chemotherapy. Conclusion: The use of gene expression profiling tests correlates with a real-world chemotherapy reduction. Gene expression profiling testing may improve patient confidence in the decision for or against chemotherapy.