Prognostische betekenis van het genexpressieprofiel van mammatumoren, bepaald met DNA-microarrays

– Adjuvant systemic drug therapy is effective in reducing the post-surgical recurrence and mortality rates of early breast cancer. Nevertheless, the majority of patients in this situation undergo potentially toxic treatment without deriving benefits. Using mRNA expression microarrays and hierarchic cluster analysis, it has been shown that breast cancer consists of several molecular subgroups, each having a different prognosis and response to treatment. In a group of 78 tumours, a so-called ‘supervised analysis’ has now shown that a reliable prediction of the prognosis regarding metastasis can be made based on the expression of a 70-gene classifier. In a second study, in patients with node-negative disease, this microarray-based assay outperformed the generally available prognostic factors such as tumour size or histopathological grade of malignancy. Microarray-based prognostication of node-negative breast cancer may markedly reduce the number of breast-cancer patients receiving unnecessary adjuvant chemotherapy. Prospective clinical studies are in progress or are being planned.

Ned Tijdschr Geneeskd 2005;149:638-46