187P - Summary of head-to-head comparisons of patient (pt) risk classifications by the 21-gene Recurrence Score (RS) assay and other genomic assays for ea...

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Breast Cancer, Early Stage
Breast Cancer
Personalised Medicine
Presenter Zsuzsanna Varga
Citation Annals of Oncology (2017) 28 (suppl_5): v43-v67. 10.1093/annonc/mdx362
Authors Z. Varga1, P. Sinn2, D. McCullough3, A. Lau3, M.C. Stöppler3, F.L. Baehner3, C. Chao4, A. Seidman5
  • 1Departement Pathologie Und Molekularpathologie, Universitätsspital Zürich, CH-8091 - Zürich/CH
  • 2Sektionsleiter Gynäkopathologie, Pathologisches Institut, Heidelberg/DE
  • 3Medical Affairs, Genomic Health, Inc., 94063 - Redwood City/US
  • 4Medical Affairs, Genomic Health, Inc., Redwood City/US
  • 5Department Of Medical Oncology, Memorial Sloan-Kettering Cancer Center, 10065 - New York/US

Abstract

Background

Many genomic assays that assess recurrence risk in EBC are prognostic, but they differ in risk group stratification, which can affect clinical utility. Prospective outcomes of > 50K pts treated based on 21-gene RS results have shown that pts with low RS EBC can safely forgo chemotherapy. Because of its extensive validation and wide clinical use, the RS assay is a common comparator in head-to-head studies with other assays.

Methods

Published/presented studies of the RS assay performed on same tumor samples with Breast Cancer Index (BCI), EndoPredict (EP) or EP+clinical features (EPclin), MammaPrint (MMP), and/or Prosigna (ROR) assays were reviewed. Study findings were summarized descriptively.

Results

14 studies were found that compared the RS assay with BCI (1), BCI, EPclin, and ROR (1), EP/EPclin (2), MMP (6), and ROR (4). Overall discordance in risk stratification ranged from 43% to 66% between assays (Table). The RS assay classifies 12% of pts as high risk, compared with EP (63%), EPclin (48%), and MMP (46%), assays with low/high risk groups, and compared with BCI (16%) and ROR (33%), assays that, like the RS assay, use three risk groups.Table:

187P

Discordancea Between the RS Assay and Other Assays
BCIROREP/EPclinMMP
Studyb1-level2-levelOverall1-level2-levelOverall1-level2-levelOverall1-level2-levelOverall
Sestak 201637%5%42%
Bartlett 2016c40%10%50%
Alvarado 201537%10%46%
Dowsett 201341%3%43%
Sinn 201745%20%66%
Varga 201329%/29%18%/21%47%/50%
Clough 201338%19%57%
Denduluri 201134%25%58%
Maroun 201531%22%53%
Shivers 201326%19%44%

a. Overall=any discordance in risk classification between the RS assay and other; 1-level=discordance of one risk category (low ↔ intermediate or intermediate ↔ high); 2-level=discordance of two risk categories (low ↔ high). b. Four studies lacked risk classification information appropriate for inclusion in this table. c. Study used nonstandard RS cutoffs for the RS vs. MMP comparison.

Conclusions

The five most common genomic assays in clinical use for EBC risk-stratify pts differently and thus are not interchangeable. Of these, the RS assay classifies the smallest proportion of pts as high risk.

Clinical trial identification

N/A

Legal entity responsible for the study

Zsuzsanna Varga

Funding

Genomic Health

Disclosure

Z. Varga: Consultant/advisor: Genomic Health, Roche. P. Sinn: Advisor: Genomic Health. D. McCullough, A. Lau, M.C. Stöppler, F.L. Baehner, C. Chao: Employment and stock ownership: Genomic Health. A. Seidman: Consultant/speaker: Genomic Health.