Gene expression profiles provide strong prognostic information and can predict breast cancer outcome mainly in women with lymph node-negative, oestrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. They are primarily designed to enable a more precise assessment on whether or not a patient needs adjuvant chemotherapy. However, the optimal use in clinical practice is still not established. The first set of data published from the TAILORx study and the results from the MINDACT study provide strong evidence for the clinical utility of gene expression profiles. Full disclosure of the results of prospective studies such as MINDACT and TAILORx on this topic is awaited in order to define their exact place in clinical decision-making. However, in several countries, these tests are already used in daily clinical practice, and are reimbursed. In addition, the use of gene expression profiles as a potential ancillary tool for treatment decisions is supported in several international treatment guidelines. Multiple studies have shown that there is a change in treatment decision based on gene expression profiles. In addition, different assays may provide different risk stratification at short-, middle- and long-term, so thoughtful use of these tests is recommended. Patients should be well informed about the benefits, risks, costs and uncertainties associated with these tests. Clinicians should also be educated on these matters. Furthermore, as gene expression profiles are expensive and not reimbursed in many countries, these tests are not accessible to all breast cancer patients. Patients’ preferences are important when making risk assessments and treatment decisions in those cases where there is doubt on the benefit of giving adjuvant chemotherapy. Taken together, gene expression profiles provide information that may be complementary to that provided by standard clinicopathological assessment in guiding decision of therapy in the adjuvant setting. These assays represent a step forward towards personalised medicine. We strongly propose to allow reimbursement of gene expression profiles in Belgium, but pragmatic and clear criteria for reimbursement should be developed with all stakeholders to avoid overconsumption.

(BELG J MED ONCOL 2016;10(4):114–122)