Abstract 103P
Background
EMIT1 is a national, observational single-arm trial designed to assess the value of the Prosigna PAM50/ROR test as a routine diagnostic tool, examining its impact on adjuvant treatment (tx) decisions vs standard histopathology, clinical outcomes, long-term side effects and cost-effectiveness. Here we present the impact of Prosigna on tx decisions.
Methods
Patients (pts) with HR+/HER2- pT1-T2 pN0 early breast cancer (EBC) were included. Prosigna test and standard histopathology assessments were performed on all tumors. Clinicians’ tx decisions were recorded before and after the Prosigna results were disclosed. Descriptive statistics, Pearson’s r and R2 were executed.
Results
Of 2203 patients included (2019-2022), 2174 tumors had conclusive Prosigna result; 62% were Lum A, 36% Lum B, 1% HER2 enriched and 1% Basal-like. The ROR score was ≤40 in 49% of tumors, 41-60 in 31% and >60 in 20%. Based on national guidelines for risk profile assessment, the pre-Prosigna tx decisions were: no systemic tx (NT) in 27% of pts (low risk), endocrine tx only (ET) in 38% (intermediate risk) and chemotherapy (CT) followed by ET (CT-ET) in 35% (higher risk). Post-Prosigna tx decisions were 25%, 51% and 24%, respectively. Adjuvant tx changed in 29% of pts, including 21% change in CT use. For pts assigned to CT pre-Prosigna, 45% were de-escalated to ET post-Prosigna. For pts allocated to ET, 12% were escalated to CT-ET and 8% de-escalated to NT. For pts allocated to NT, 18% were escalated to ET/CT-ET. For pts with pT1c-2 G2 and intermediate Ki67 (0.5-1.5x hospitals own median Ki67), the pre-Prosigna tx decision varied widely across hospitals (i.e. use of CT <5–51%). Post-Prosigna, the variability in CT use was markedly reduced (8–24%). Overall, the correlation between Ki67 and ROR score was moderate (r=0.66) with large variation between hospitals (r=0.49-0.83/R2=0.24-0.68). The median ROR score increased by increasing grade, but the ROR score-ranges were wide (for G1 0-79, G2 0-90, G3 16-94).
Conclusions
The Prosigna-test result changed adjuvant tx decisions in all EBC clinical risk groups, markedly decreased the CT use for pts with higher clinical risk and reduced treatment decision discrepancies between hospitals.
Clinical trial identification
NCT03904173. Oct 29, 2018.
Legal entity responsible for the study
Oslo University Hospital.
Funding
Norwegian Cancer Society, Pink Ribbon and Clinical therapy research in the specialist health services, Norway. Test discount from Nanostring/Veracyte.
Disclosure
E.S. Blix: Non-Financial Interests, Institutional, Advisory Role: AstraZeneca, Daiichi Sankyo, Eli Lilly, Gilead, MSD, Novartis. S.X. Raj: Financial Interests, Institutional, Invited Speaker, Lecture Honoraria: Pfizer, AstraZeneca, Novartis. H.P. Eikesdal: Financial Interests, Institutional, Invited Speaker, Honoraria: Amgen, Bristol Myers Squibb, Dagens Medisin, HAI Interaktiv AS; Financial Interests, Institutional, Invited Speaker, Honoraria + Travel/accomaodation expences: AstraZeneca; Financial Interests, Institutional, Invited Speaker, Honoraria and Advisory Role: Novartis; Financial Interests, Institutional, Invited Speaker, Honoraria and Advisory Role and Expert Testemony: Pfizer; Financial Interests, Institutional, Invited Speaker, Honoraria and Advisory Role +Travel/Accomodation expences: Pierre Fabre; Non-Financial Interests, Institutional, Advisory Role: Aptitude Health, Daiichi Sankyo, Eli Lilly, medac, MSD, Roche. B. Gilje: Financial Interests, Institutional, Advisory Board, Honoraria: Eli Lilly, Gilead, Daiichi Sankyo, Roche, Pierre Fabre. All other authors have declared no conflicts of interest.