Prediction of Distant Recurrence by EndoPredict in Patients with Estrogen Receptor-Positive, HER2-Negative Breast Cancer who Received Adjuvant Endocrine Therapy plus Chemotherapy (ET+C) or Endocrine Therapy Alone (ET)
Ivana Sestak1, Miguel Martin2, Peter Dubsky3, Federico Rojo4, Jack Cuzick1, Martin Filipits5, Amparo Ruiz6, William Gradishar7, Hatem Soliman8, Lee Schwartzberg9, Richard Buus10, Dominik Hlauschek11, Alvaro Rodriguez-Lescure12, Michael Gnant13
1 Centre for Cancer Prevention, QMUL, London, UK; 2 Hospital General Universitario Gregorio Maranon/GEICAM, Madrid, Spain; 3 Klink St. Anna/ABCSG, Lucerne, Switzerland; 4 CIBERONC-ISCII Fundacion Jimenez Diaz/GEICAM, Madrid, Spain; 5
Medical University Vienna/ABCSG, Vienna, Austria; 6 Instituto Valenciano de Oncologia/GEICAM, Madrid, Spain; 7 Robert H. Lurie Comprehensive Cancer Centre of NWU, Chicago, US; 8 H. Lee Moffitt Cancer Center, Tampa, US; 9 West Cancer
Center, Germantown, US; 10 The Breast Cancer Now Toby Robins Research Centre/ICR, London, UK; 8 Austrian Breast and Colorectal Group (ABCSG), Vienna, Austria; 9 Hospital Universitario de Elche/GEICAM, Valencia, Spain
Summary
- Chemobenefit validated:
- In over 3,700 patients with ER+, HER2- breast cancer.
- With modern (taxane-containing) treatment regimens.
- Patients with a low-risk EndoPredict result did not benefit from the addition of chemotherapy.
- Patients with a higher EndoPredict score had a greater benefit from chemotherapy.
Background
EndoPredict (EPclin) is a prognostic test validated for early breast cancer patients with estrogen (ER) receptor positive, HER2-negative disease to help make decisions between 5 years of endocrine therapy alone or with chemotherapy.1,2,3
Objective
To investigate in a non-randomized setting whether EPclin can predict chemotherapy benefit in pre- and post-menopausal women with ER-positive, HER2-disease who have received five years of endocrine therapy alone (ET) or in combination with chemotherapy (ET+C).
Methods
- A total of 3,746 women with ER-positive, HER2-negative disease were included in this analysis.
- The primary objective was to evaluate the 10-year distant recurrence-free interval (DRFI) rates as a continuous function of EPclin separately for patients in ET+C and ET.
Results


- Patients with a low-risk EndoPredict result did not benefit from the addition of chemotherapy.
- Patients with higher EndoPredict scores had a greater benefit from chemotherapy.
- Baseline demographics for the two cohorts are shown in Table 1.
- Median follow-up for those on ET alone was 9.6 years (IQR 6.0-10.0) vs. 9.2 years (7.5-10.0) for ET+C.
- Clear distinction in 10-year risk between ET alone vs ET+C as the EndoPredict score increases (Figure 2).
- Interaction between EPclin and treatment was significant (P=0.02).
Conclusions
- Patients with a high EPclin score on ET+C had a significantly lower 10-year distant recurrence (DR) risk than those on ET alone.
- No differences in 10-year DR risks were observed between ET alone and ET+C for low EPclin scores (<3.3 low risk cut-off).
- Interaction between EPclin and treatment was significant (P=0.02).
- Potential benefit of adding chemotherapy to those with high EPclin scores.
- Patients with higher EPclin scores have a disproportionate benefit from chemotherapy.
- Results give insight into the predictive value of EPclin for women with ER-positive, HER2-negative breast cancer.
References
1. Dubsky et al., 2012; 2. Buus et al., 2017; 3. Martin et al., 2014