The 21-gene recurrence score complements IBTR! Estimates in early-stage, hormone receptor-positive, HER2-normal, lymph node-negative breast cancer

Nikhil G Thaker,Michael C Stauder,Lei Huo,Wendy A Woodward,Karen E Hoffman,Mark F Munsell,Eric A Strom,Welela Tereffe,Simona F Shaitelman,Benjamin D Smith,George H Perkins,Lajos Pusztai,Thomas A Buchholz

doi:10.1186/s40064-015-0840-y

Abstract

Clinicians have traditionally used clinicopathological (CP) factors to determine locoregional recurrence (LR) risk of breast cancer and have generated the IBTR! nomogram to predict the risk of ipsilateral breast tumor recurrence (IBTR). The 21-gene recurrence score (RS) assay was recently correlated with LR in retrospective studies. The objective of this study was to examine the relationship between the RS and IBTR!. CP characteristics of 308 consecutive patients who underwent RS testing at our institution were examined. IBTR! was used to estimate the risk of 10-year IBTR. Descriptive statistics were used to compare the RS with the estimated IBTR!. Given a low event rate in this cohort, actual IBTR rates were not reported. Most patients had stage I/II (98%) and grade I/II (77%) disease. Median age was 54 years (range, 30–78). Median IBTR! without radiation therapy was 10% (mean, 12% [range, 4-43%]). RS was low (<18), intermediate (18–30), and high (>30) in 52% (n = 160), 40% (n = 123), and 8% (n = 25) patients. Overall, IBTR! did not correlate with RS (P = .77). We saw no correlation between RS and IBTR! in patients with less than (P = .32) or greater than (P = .48) a 10% risk of IBTR. Interestingly, Ki-67 expression correlated with both IBTR! (P = .019) and the RS (P = .002). Further study is warranted to determine if the RS can provide complementary biological information to CP factors in estimating the risk of LR. Prospective studies evaluating this association may potentially allow for individualized treatment decisions.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-0840-y) contains supplementary material, which is available to authorized users.

Highlights

Local treatment decisions for patients with breast cancer are traditionally based on conventional clinicopathological (CP) factors such as age, tumor size and grade, TNM stage, margin status, lymphovascular invasion (LVSI), chemotherapy use, and hormone therapy use
Breast cancer represents a heterogeneous group of diseases, and additional biological information about tumor gene expression may assist in local therapy decisions
Despite major progress in identifying genomic profiles associated with risk of distant recurrence (DR) and benefit of chemotherapy, only recently have studies demonstrated that the 21-gene Recurrence Score (RS) may help estimate the risk of locoregional recurrence (LR) (Voduc et al 2010; Mamounas et al 2010)

Summary

Introduction

Local treatment decisions for patients with breast cancer are traditionally based on conventional clinicopathological (CP) factors such as age, tumor size and grade, TNM stage, margin status, lymphovascular invasion (LVSI), chemotherapy use, and hormone therapy use. The most widely used gene expression profiling tool is the 21-gene Oncotype Dx Recurrence Score (RS) assay (OncotypeDX; GenomicHealth Inc., Redwood City, Calif.), which is used to estimate the risk of 10-year distant recurrence (DR) and predict the likelihood of benefit of adjuvant chemotherapy for hormone receptor (HR)-positive, node-negative, tamoxifen-treated breast cancer (Paik et al 2004; Paik et al 2006). Both the National Comprehensive Cancer Network and American Society of Thaker et al SpringerPlus (2015)4:36. We sought to identify clinical scenarios in which the RS may complement CP information when making individualized local management decisions

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Conclusion