Real-life Evaluation of Endopredict® in Early HR+/HER2- Breast Cancer

French Prospective Real-life Evaluation of the Endopredict® Genomic Signature for HR-positive,HER2-negative Early Breast Cancer

EndoPredict is a genomic signature used to determine the 10-year risk of recurrence in early HR+/HER2- breast cancers classified as of intermediate risk according to conventional clinical and pathological criteria, and to guide the adjuvant treatment decision: hormone therapy alone or hormone therapy and chemotherapy.

Since 2016, french laboratories performing the Endopredict test, included prospectively analyzed tumors in the SiMoSein registry with data collection : age, tumor size, lymph node status, histology, grade, HR and HER2 IHC status, Ki67, EPscore, Epclin score, risk of relapse, absolue benefit from chemotherapy, risk of late relapse

The main objectives of the trial are to:

Evaluate long-term relapse-free survival and overall survival over a 10-year period in breast cancer patients who underwent EndoPredict® testing according to:

• EPclin risk class (low vs. high),
• Lymph node status (N0/N1),
• Tumor size (pT),
• Age groups (<40 years, 40-49 years, 50-69 years, ≥70 years),
• EP score alone.

This study provide real-life data to determine the clinical usefulness of this molecular signature in the management of early HR+/HER2- breast cancers. The ultimate goal is to be able to offer therapeutic de-escalation (avoiding chemotherapy) to patients who are reliably assessed as having a low risk of relapse.

Inclusion Criteria:

• Patient with early breast cancer, hormone receptor-positive, HER2 non-amplified, for whom clinical criteria are deemed insufficient to determine the need for adjuvant chemotherapy, combined with hormone therapy, after breast surgery.

Exclusion Criteria:

• Patients who did not undergo testing or whose test results were not validated