Oncotype DX® – revolutionary genomic testing in patients with breast cancer at the conference in St. Gallen

The American company Genomic Health presented interesting results from the total of 22 studies on the accuracy and clinical validity of data from Oncotype DX® multigene breast cancer assay at a highly prestigious International Conference on Breast Cancer, traditionally held in St. Gallen in Switzerland in March.

New data continues to confirm that decisions on the type of therapy may be changed and more economic use of the costs of therapy may be achieved based on the assay. This fact has been verified by health care provision systems in various countries. Thanks to the unique number of conducted studies and consistency of their results, Oncotype DX® assay provides an indisputable benefit for the prediction of chemotherapy administered in patients with breast cancer.

Some conclusions from St. Gallen:

Data was presented at the conference in St. Gallen, confirming that Oncotype DX® is currently the only genomic test able to really predict the success rate of chemotherapy in breast cancer. This assay was developed in order to provide doctors with a unique answer to the question whether patients with estrogen receptor positive breast cancer (representing about 75% of all breast cancer diagnoses) actually need chemotherapy as an adjuvant treatment for their hormonal therapy.

Current clinical evidence for Oncotype DX® includes 5,854 patients enrolled in 6 unique prospective studies. Based on the studies, Oncotype DX® is currently the only assay that provides 1B level of evidence for clinical use in individuals with early-stage, hormonally positive, invasive breast cancer.

  • For example, results of an analysis of 67 patients who underwent Oncotype DX® and Mammaprint 70 testing were presented in St. Gallen. It was found that 45% of patients defined as “high risk“ based on Mammaprint 70 were assessed as “low risk“ according to Oncotype DX®, thus as patients who have an absolutely minimum (if any) benefit from adjuvant chemotherapy, and on the contrary, in whom hormonal therapy alone provides the best benefit.
  • Mammaprint 70 failed completely in 15% samples, while Oncotype DX® provided valid information in all cases. This data confirms the conclusions of ASCO 2011 conference, which say that 39% patients classified as “high risk“ according to Mammaprint 70 had to be reclassified as low risk individuals according to Oncotype DX®.
  • Some of the presented pharmacoeconomic data was no less interesting. For example, a French study found that the use of Oncotype DX® as the “decision-making“ tool for considerations of whether adjuvant chemotherapy should be administered or not can save up to EUR 5 mil. – which were the costs associated with unnecessary administration of chemotherapy in patients who have no benefit from this therapy.