KCE Report 298 (2018)
Breast cancer is the most commonly diagnosed cancer in women in Belgium and throughout the world. Provided this cancer is in the early stage, treatment is essentially locoregional, that is, via surgery alone or combined with radiation therapy. In theory, this treatment is enough to eradicate the tumour since it is still limited. However, it is known that about 30% of patients treated in this way are at risk of developing remote metastases, because metastatic cancerous cells are already present but undetectable at the time of diagnosis. To eradicate these metastatic cells, some patients receive chemotherapy referred to as “adjuvant”, following the initial treatment, in the hope of stopping any disease course.
Being able to identify the women who have such metastases which are still undetectable thus represents a considerable challenge because this would allow chemotherapy to be avoided in all of the other women. Numerous teams are thus attempting to develop tests which allow the risk of metastasis and the chances of response to the chemotherapy to be determined.
Mammaprint® is one of these tests. The goal of this study was to determine whether its addition to the traditional methods for evaluating risk would allow chemotherapy to be avoided in patients at elevated clinical risk of metastasis with decreasing their chances of survival. The response is, unfortunately, that it is still too early to be able to conclude this, on the one hand because there are still too many uncertainties on its clinical utility and on the other hand because there is a lack of detailed data on the approaches used by Belgian oncologists when choosing whether or not to administer adjuvant chemotherapy.