ONLY A THIRD OF ELIGIBLE BREAST CANCER PATIENTS RECEIVE A GENE EXPRESSION TEST

Researcher Joyce Meijer, PhD student at the University of Twente and IKNL, analysed the effect of the reimbursement policy on the use of gene expression tests. Before reimbursement, only 9 per cent of eligible patients received a test. Since October 2023, when reimbursement was introduced in the Netherlands, this percentage has increased to 37 per cent. This could mean that in 2024, more than 1,000 eligible women may not have received the test.

Sabine Siesling, principal investigator at IKNL and professor at the University of Twente, leader of this study: "It is good to see that reimbursement clearly stimulates use. But the use of gene expression tests still falls short of what can be expected. About two-thirds of the patients who are eligible for it still do not receive a test. And that's a shame, because this can mean that women receive chemotherapy unnecessarily." The use of the test is still increasing each year; by now, the total percentage will be higher again.

The research results show that gene expression test outcomes are strongly related to the final treatment decision. Among patients classified as high-risk based on the test results, 83 per cent (MammaPrint) and 85 per cent (Oncotype DX) received chemotherapy. In contrast, chemotherapy was not administered in 93 and 97 per cent of cases among patients classified as low risk, respectively. This highlights the value of these tests in preventing overtreatment and avoiding unnecessary side effects.

Notably, of the patients who were eligible for a gene expression test but did not receive it, more than half (52 per cent) received chemotherapy. Siesling: "This suggests that the lack of test information may lead to a broader use of chemotherapy than may be necessary." This is an important finding, because chemotherapy is, of course, associated with well-known side effects. At the same time, it is not possible to determine what the test result would have been in these patients, because these data are lacking.

The results show that gene expression tests are an important tool for appropriate care for breast cancer, but their use is not yet optimal. To gain a better understanding of the barriers to the use of these tests, IKNL is starting an implementation project together with the University of Twente, a group of clinicians and researchers. The aim is to better identify obstacles to use and to further support appropriate care. This project is made possible by a grant from ZonMw.

The goal is to develop a national implementation plan for the appropriate use of this type of test across all regional oncology networks. This plan can also give direction to the possible future use of new tests, such as Prosigna. Recently, research by University College London showed that about two-thirds of breast cancer patients can be treated with hormone therapy instead of chemotherapy. The Prosigna test distinguishes between the groups that benefit from this and those that do not.

The full scientific article is published in the International Journal of Cancer. It is available online via Wiley: Impact of Reimbursement on the Utilisation of Gene Expression Profiles and Chemotherapy Decision‐Making in Dutch Breast Cancer Patients.