Estrogen Receptor Expression in 21-Gene Recurrence Score Predicts Increased Late Recurrence for Estrogen-Positive/HER2-Negative Breast Cancer.

Abstract

PURPOSE:

To identify the individual genes or gene modules that lead to the OncoptypeDx 21-gene recurrence score's reduced performance after 5 years and thereby identify indices of residual risk that may guide selection of patients for extended adjuvant therapy.

EXPERIMENTAL DESIGN:

We conducted a retrospective assessment of the relationship between (i) the individual genes and gene modules of the Recurrence Score and (ii) early (0-5 years) and late (5-10 years) recurrence rates in 1,125 postmenopausal patients with primary estrogen receptor-positive breast cancer treated with anastrozole or tamoxifen in the Arimidex, Tamoxifen, Alone or Combined (ATAC) randomized clinical trial.

RESULTS:

In the HER2-negative population (n = 1,009), estimates of recurrence risk were similar between years 0-5 and 5-10 for proliferation and invasion modules but markedly different for the estrogen module and genes within it (all split at the median): for low estrogen module, annual recurrence rates were similar across the two time windows (2.06% vs. 2.46%, respectively); for high estrogen module, annual rates were 1.14% versus 2.72%, respectively (P interaction = 0.004). Estrogen receptor transcript levels showed inverse prediction across the time windows: HR, 0.88 (0.73-1.07) and 1.19 (0.99-1.43), respectively (P interaction = 0.03). Similar time-, module-, and estrogen-dependent relationships were seen for distant recurrence.

CONCLUSIONS:

Patients with tumors with high estrogen receptor transcript levels benefit most from 5 years' endocrine therapy but show increased recurrence rates after 5 years and may benefit from extended therapy. Improved prognostic profiles may be created by considering period of treatment and follow-up time.

• Authors: Mitch Dowsett, Ivana Sestak, Richard Buus, Elena Lopez-Knowles, Elizabeth Mallon, Anthony Howell, John F Forbes, Aman Buzdar, Jack Cuzick
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 21 Issue 12 Pg. 2763-70 (Jun 15 2015) ISSN: 1557-3265 [Electronic] United States
• PMID: 26078431 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: ©2015 American Association for Cancer Research.

Chemical References

• RNA, Messenger
• Receptors, Estrogen
• Receptor, ErbB-2

Topics

• Breast Neoplasms (epidemiology, genetics, pathology)
• Female
• Follow-Up Studies
• Gene Expression
• Humans
• Neoplasm Recurrence, Local
• RNA, Messenger (genetics)
• Receptor, ErbB-2 (genetics)
• Receptors, Estrogen (genetics, metabolism)
• Time Factors