102893-125

Prognostic impact of the 21-gene recurrence score (RS) on disease-free and overall survival of node-positive, ER-positive breast cancer patients (pts) treated with adjuvant chemotherapy: Results from NSABP B-28.

Subcategory: 
Category: 
Risk Assessment Prevention Detection and Screening
Session Type and Session Title: 
General Poster Session A
General Session II: Risk Assessment, Prevention, Detection, and Screening
Abstract Number: 

01

Citation: 

J Clin Oncol 30, 2012 (suppl 27; abstr 1)

Author(s): 

Eleftherios P. Mamounas, Gong Tang, Soonmyung Paik, Frederick L. Baehner, Qing Liu, Jong-Hyeon Jeong, Seong-Rim Kim, Steven M Butler, Farid Jamshidian, Diana B. Cherbavaz, Steven Shak, Thomas B. Julian, Barry C. Lembersky, D. Lawrence Wickerham, Joseph P. Costantino, Norman Wolmark


Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy are designated with a caret symbol (^).

Abstract Disclosures

Abstract: 

Background: RS predicts outcome in node- and node+, ER+ pts treated with adjuvant endocrine therapy as well as benefit from adjuvant chemotherapy, with high RS receiving most of the benefit. We studied the prognostic impact of RS in node+, ER+ pts treated with adjuvant chemotherapy plus endocrine therapy as part of the NSABP B-28 trial. Methods: B-28 compared doxorubicin/cyclophosphamide (ACX4) with ACX4 followed by paclitaxel X4. Pts >50 yrs and those<50 yrs with ER+ and/or PR+ tumors also received 5 yrs of tamoxifen concurrently with chemotherapy. Between 8/95 and 5/98 3060 pts were accrued. The present study includes 1,065 pts ER+ by central tissue microarray IHC assay, tamoxifen treated, assessed by RS. Median follow-up time was 11.2 yrs. Results: Of the 1,065 pts, 386 (36%) had low RS<18; 364 (34%) intermediate RS,18-30; and 315 (30%) high RS≥31. In univariate analyses RS was a significant predictor of DFS, distant recurrence-free interval (DRFI) and OS (Table). In multivariate analyses, RS provided independent prognostic information for all three endpoints beyond clinical and pathologic factors, e.g., treatment, age, tumor size, tumor grade, number of + nodes and type of surgery (p<0.001). Conclusions: The 21-gene RS maintains significant prognostic impact in ER+, node+ pts who have received anthracycline- or anthracycline/taxane-based adjuvant chemotherapy. These findings emphasize the need to target pts with high residual risk for recurrence with additional therapies to overcome unfavorable biology, potential endocrine and/or chemotherapy resistance. Supported by: NCI, HHS, PHS, grants U10-CA-12027, -69651, -37377, -69974, and U24-CA-114732, and grants from Susan G. Komen for the Cure and Bristol-Myers Squibb Pharmaceutical Research Institute.

Kaplan-Meier estimates of 10-yr DFS, DRFI, and OS.
Endpoints RS low
n = 386
RS intermed
n = 364
RS high
n = 315
Log-rank
p value
DFS %;
95%CI
75.8
(71.1-79.8)
57.0
(51.6-61.9)
48.0
(42.3-53.4)
p<0.001
DRFI %;
95%CI
80.9
(76.4-84.6)
64.9
(59.6-69.7)
55.8
(50.0-61.2)
p<0.001
OS %;
95%CI
90.0
(86.4-92.6)
74.7
(69.8-78.9)
63.0
(57.4-68.2)
p<0.001