ASCO Abstract 2: Comparison of StemPrintER with Oncotype DX in the TransATAC cohort.

14th May 2020


Comparison of StemPrintER, a Novel Biology-based Genomic Predictor of Distant Recurrence in Breast Cancer, with Oncotype DX in the TransATAC cohort.


S. Pece1,2, I. Sestak3, F. Montani1, M. Tillhon1, S. Freddi1, P. Maisonneuve1, M. Colleoni1, D. Disalvatore, G. Viale1, R. Buus4,5, J. Cuzick3, M. Dowsett4,5, and P.P. Di Fiore1,2.


1IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy.

2Dipartimento di Oncologia e Emato-oncologia, Università degli Studi di Milano, Milan, Italy.

3Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, United Kingdom.

4The Breast Cancer Now Toby Robins Research Centre at The Institute of Cancer Research, London, United Kingdom.

5Ralph Lauren Centre for Breast Cancer Research, Royal Marsden Hospital, London, United Kingdom.


Accurate prediction of distant metastasis (DM) in early stage ER+/HER2- breast cancer (BC) patients is vital to avoid over/under-treatment with adjuvant chemotherapy (CT). The OncotypeDX Recurrence Score (RS) is a widely used tool to assist clinical decision-making for CT. The StemPrintER Risk Score (SPRS) is an alternative genomic predictor based on the biology of cancer stem cells that predicts recurrence risk in ER+/HER2- BCs (Pece S. et al., EBioMedicine 2019). Here, we analyze the prognostic value of SPRS in the TransATAC cohort of post-menopausal ER+/HER2- BC patients, and compare the prognostic information provided by SPRS and RS for 10-year risk of DM.


The likelihood χ2 (LRχ2) and Kaplan-Meier survival analyses were used to assess prognostic information provided by SPRS, RS and the clinical treatment score (CTS) in 818 TransATAC patients treated with anastrozole or tamoxifen for 5 years. Comparative analyses were made for DM risk over the 10-year follow-up, as well as in the early (0-5 years) or late (5-10 years) interval, according to nodal status.


Used as a continuous variable, SPRS was an independent predictor of DM in years 0-10 among all patients (HR=1.71, P<0.0001, LRχ2: 29.7), as well as in node-negative (N0) and node-positive (N1-3) patients (N0: HR=1.83, P<0.0001, LRχ2=22.8; N1-3: HR=1.42, P=0.026, LRχ2=4.9). A predefined SPRS cut-off was used to stratify patients into low vs. high risk groups (LOW: N=454, 10-year DM rate=5.8%; HIGH: N=364, 10-year DM rate=21.9%; HRHIGH vs. LOW=4.04; P<0.0001.

SPRS outperformed RS in providing prognostic information for 10-year DM risk (SPRS: HR=1.79, P<0.0001, LRχ2=33.4; RS: HR=1.52, P<0.0001, LRχ2=22.1), with even greater differences in late DM prediction in N0 patients. SPRS also provided more prognostic information than RS to CTS (ΔLRχ2: SPRS+CTS vs. CTS= 14.9; RS+CTS vs. CTS= 9.7).


In ER+/HER2- TransATAC BC patients, SPRS was highly prognostic for DM and was superior to RS in providing additional prognostic information to conventional clinicopathological parameters.