Two multi-gene tests designed to predict the risk of disease progression and response to chemotherapy in breast cancer produce broadly similar results for high- and low-risk patients, but do not always agree in their predictions for those at intermediate risk, a new analysis shows.
In recent years, several genomic tests have been developed to provide prognostic information for breast cancer. Dr Catherine Kelly from Mater Misericordiae University Hospital, Dublin, Ireland, and colleagues in the USA examined the agreement in prediction results between two multi-gene assays --the widely used Oncotype DX and a newer PAM50 breast cancer intrinsic classifier.
"At the present time we know there are at least four different breast cancer sub-types with clinical relevance --'luminal A', 'luminal B', 'basal-like' and 'Her2-enriched'. Several commercial assays are being introduced to assign clinical sub-type or predict risk of recurrence for breast cancer," Dr Kelly explained.
"An imminent clinical challenge for practicing physicians is to understand how these different assays relate to each other and what to expect when more than one assay is performed on the same cancer. This is the first study to compare two standardized, readily available but conceptually different prognostic risk predictors."
OncotypeDX is intended for use in patients with hormone receptor-positive, lymph node-negative breast cancer to identify women at low risk of breast cancer recurrence who safely can avoid chemotherapy. It measures the activity of 21 genes and generates a recurrence score (RS) which categorizes patients into low, intermediate or high risk groups depending on the risk of distant recurrence.
The PAM50 breast cancer intrinsic classifier measures the expression of 50 genes and stratifies breast cancers into five sub-types; luminal A, luminal B, basal-like, Her2-enriched and normal-like, so the target population is not just patients wi
|Contact: Vanessa Pavinato|
European Society for Medical Oncology