Breast Cancer Test Predicts Late Recurrence
Clinicians can identify patients who will benefit most from extended hormonal therapy
New study data have shown that results from the Oncotype DX test (Genomic Health, Inc.) can predict the risk of late distant recurrence in patients with early-stage breast cancer after initial treatment with tamoxifen, suggesting that the test may help identify patients with the greatest potential to benefit from extended hormonal treatment beyond 5 years.
The findings will be presented June 2 at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
The new study analyzed 668 and 1,065 patients from the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-14 and B-28 trials, respectively. Median follow-up periods of 13.9 years (B-14) and 11.2 years (B-28) determined that the Oncotype DX recurrence score results were significantly associated with distant recurrence after 5 years in patients whose tumors had high ER expression. Specifically, in B-14 patients, the association of the continuous recurrence score with distant recurrence after 5 years in the patients with higher quantitative estrogen receptor (ER) expression was significant (P = 0.004) after adjustment for age, grade, and tumor size.
The results suggest that extending tamoxifen therapy beyond 5 years may be most beneficial in patients with high and intermediate recurrence scores and with higher quantitative ER expression. Conversely, patients with low recurrence scores would be expected to obtain limited benefit from extended tamoxifen therapy beyond 5 years because of their much lower risk for late distant recurrence.
The Oncotype DX test was introduced a decade ago.
Source: Genomic Health Inc.; May 29, 2014.