Association between the 21-gene recurrence score assay and risk of locoregional recurrence in node-negative, estrogen receptor-positive breast cancer: results from NSABP B-14 and NSABP B-20.

Abstract

PURPOSE:

The 21-gene OncotypeDX recurrence score (RS) assay quantifies the risk of distant recurrence in tamoxifen-treated patients with node-negative, estrogen receptor (ER)-positive breast cancer. We investigated the association between RS and risk for locoregional recurrence (LRR) in patients with node-negative, ER-positive breast cancer from two National Surgical Adjuvant Breast and Bowel Project (NSABP) trials (NSABP B-14 and B-20).

PATIENTS AND METHODS:

RS was available for 895 tamoxifen-treated patients (from both trials), 355 placebo-treated patients (from B-14), and 424 chemotherapy plus tamoxifen-treated patients (from B-20). The primary end point was time to first LRR. Distant metastases, second primary cancers, and deaths before LRR were censored.

RESULTS:

In tamoxifen-treated patients, LRR was significantly associated with RS risk groups (P < .001). The 10-year Kaplan-Meier estimate of LRR was 4.% (95% CI, 2.3% to 6.3%) for patients with a low RS (< 18), 7.2% (95% CI, 3.4% to 11.0%) for those with intermediate RS (18-30), and 15.8% (95% CI, 10.4% to 21.2%) for those with a high RS (> 30). There were also significant associations between RS and LRR in placebo-treated patients from B-14 (P = .022) and in chemotherapy plus tamoxifen-treated patients from B-20 (P = .028). In multivariate analysis, RS was an independent significant predictor of LRR along with age and type of initial treatment.

CONCLUSION:

Similar to the association between RS and risk for distant recurrence, a significant association exists between RS and risk for LRR. This information has biologic consequences and potential clinical implications relative to locoregional therapy decisions for patients with node-negative and ER-positive breast cancer.

• Authors: Eleftherios P Mamounas, Gong Tang, Bernard Fisher, Soonmyung Paik, Steven Shak, Joseph P Costantino, Drew Watson, Charles E Geyer Jr, D Lawrence Wickerham, Norman Wolmark
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 28 Issue 10 Pg. 1677-83 (Apr 01 2010) ISSN: 1527-7755 [Electronic] United States
• PMID: 20065188 (Publication Type: Journal Article)

Chemical References

• Receptors, Estrogen
• Tamoxifen

Topics

• Breast Neoplasms (drug therapy, genetics, pathology)
• Clinical Trials as Topic
• Gene Expression Profiling
• Humans
• Lymphatic Metastasis
• Middle Aged
• Neoplasm Metastasis (genetics)
• Neoplasm Recurrence, Local (genetics)
• Neoplasms, Hormone-Dependent (drug therapy, genetics, pathology)
• Receptors, Estrogen (metabolism)
• Risk Assessment
• Tamoxifen (therapeutic use)