Oncotype DX® Breast Cancer Test Predicts Late Recurrence Five to 15 Years Out
Genomic Health, Inc. last year announced results of a large, positive study that confirmed that the Oncotype DX® test results for Recurrence Score® and quantitative estrogen-receptor (ER) predict late distant recurrence risk in early-stage breast cancer patients after initial tamoxifen therapy, suggesting that Oncotype DX may help identify which patients have greater potential to benefit from extended hormonal treatment beyond five years. One of many Oncotype DX studies was presented at the 2014 American Society of Clinical Oncology® (ASCO®) Annual Meeting taking place in Chicago.
This new study analyzed 668 and 1065 patients from the original NSABP B-14 and B-28 trials, respectively. results determined that the Oncotype DX Recurrence Score results were significantly associated with distant recurrence after five years in patients whose tumors had high estrogen receptor expression. Specifically, in the NSABP B-14 patients, the association of the continuous Recurrence Score with distant recurrence after five years in the higher ER patients was significant (p=0.004) after adjustment for age, grade and tumor size. The results suggest that extending tamoxifen beyond five years may be most beneficial in patients with high and intermediate Recurrence Scores with higher quantitative ER expression. Conversely, patients with low Recurrence Score results would be expected to have limited benefit from extended tamoxifen beyond five years due to much lower risk for late distant recurrence.