KEY TAKEAWAYS
- The EMIT1 study determined the efficacy of the Prosigna PAM50/ROR test as a potent diagnostic tool in EBC.
- The results from the Prosigna test influenced adjuvant treatment choices across all EBC risk categories.
The EMIT1 study is a national, single-arm observational trial that evaluated the effectiveness of the Prosigna PAM50/ROR test as a standard diagnostic method. It focused on the test’s influence on adjuvant treatment choices in comparison to standard histopathology, its clinical results, long-term side effects, and cost-effectiveness.
Patients (pts) diagnosed with HR+/HER2- pT1-T2 pN0 early breast cancer (EBC) were involved in the study. Both the Prosigna test and standard histopathological evaluations were conducted on all tumors. Medical treatment decisions were recorded both prior to and after disclosing Prosigna outcomes. Descriptive statistics, including Pearson’s r and R2 were undertaken.
Out of the 2203 pts studied from 2019-2022, results from 2174 tumors from the Prosigna test were definitive: 62% were Lum A, 36% Lum B, 1% HER2 enriched, and 1% Basal-like. ROR scores showed 49% ≤40, 31% between 41-60, and 20% >60. Based on national risk assessment guidelines, decisions for treatment before Prosigna were as follows: 27% didn’t undergo systemic treatment (low risk), 38% received only endocrine treatment (intermediate risk), and 35% underwent chemotherapy followed by endocrine treatment (higher risk). Post-Prosigna treatment decisions shifted to 25%, 51%, and 24%, respectively.
There was a treatment alteration in 29% of pts, with a 21% variation in chemotherapy usage. Before Prosigna, 45% of the pts designated for chemotherapy were transitioned to endocrine treatment. Meanwhile, 12% initially slated for endocrine treatment shifted to combined treatment, and 8% shifted to no treatment. 18% of pts initially allocated no treatment shifted to either endocrine or combined treatments.
Treatment decisions before the Prosigna test displayed vast differences across hospitals, especially for pts with pT1c-2 G2 and intermediate Ki67. This variability was significantly reduced after the Prosigna results. There was a moderate correlation between Ki67 and the ROR score, with variations observed across different hospitals. The ROR score generally increased with the tumor grade, but broad ranges were within each grade.
The results from the Prosigna test impacted the treatment choices across all EBC risk categories. There was a notable reduction in chemotherapy usage for patients deemed at higher clinical risk and a significant reduction in treatment decision discrepancies across different hospitals.
Clinical Trial: https://classic.clinicaltrials.gov/ct2/show/NCT03904173
Ohnstad, H., Borgen, E., Mortensen, E., Brekke, M.B., Akslen, L.A., Janssen, E.A.M., Geitvik, G.A., Rypdal, M.C., Langerød, A., Halset, E.H., Blix, E.S., Raj, S.X., Eikesdal, H.P., Gilje, B., Skjerven, H., Sclichting, E., Reinertsen, K.V., Falk, R.S., Russnes, H.E.G., Naume, B. IMPACT OF PROSIGNA TEST ON TREATMENT DECISION IN LYMPH NODE NEGATIVE EARLY BREAST CANCER- A PROSPECTIVE MULTICENTER STUDY (EMIT1). Annals of Oncology (2023) 8 (1suppl_4): 101219-101219. 10.1016/esmoop/esmoop101219
