Study shows Oncotype DX Breast diagnostic test accurately predicts recurrence risk of breast cancer- Genomic Health

Genomic Health, announced that the Journal of Clinical Oncology published results from a large study confirming the ability of the Oncotype DX Breast diagnostic test Recurrence Score, in combination with quantitative estrogen-receptor (ER) expression, to accurately predict after five years of tamoxifen therapy the risk of late distant recurrence up to 15 years in patients with early-stage, hormone receptor-positive breast cancer. These findings suggest that Oncotype DX may help identify which patients are most likely to benefit from extended hormonal treatment with tamoxifen.

The study analyzed the results of two clinical trials: NSABP B-14 (668 patients) and B-28 (1,065 patients). Patients were followed up on for a median of 13.9 years (B-14) and 11.2 years (B-28). The results reconfirm earlier findings from validation studies of Oncotype DX which demonstrated that Breast Recurrence Score results were strongly associated with distant recurrence up to 15 years for patients with node-positive and node-negative disease. The new study also showed that in patients with greater ER expression, the association of the continuous Breast Recurrence Score with distant recurrence was significant after adjustment for age, grade and tumor size. The results suggest that extending tamoxifen beyond five years may provide greater benefit in patients with high and intermediate Breast Recurrence Score results who also show high ER expression. Conversely, patients with low Breast Recurrence Score results have a much lower risk of late distant recurrence and would be expected to have less benefit from extended tamoxifen beyond five years.