PRELUDE

A Prospective, Multicenter REgistry to Observe the Treatment Patterns, ClinicaL OUtcomes, and Decision-Making in Patients with Early Breast Cancer Eligible for EndoPredict® Testing.

Study objective

The objective of the study is to observe and document the therapeutic decision-making process, treatment protocols, and clinical outcomes in patients with luminal breast cancer, whether they have undergone EndoPredict® testing or not. In addition, beyond the general population with luminal breast cancer, the study aims to focus on subgroups with specific characteristics and to evaluate the effectiveness of the EndoPredict® test under real-world clinical conditions.

Inclusion criteria

Participants must meet all of the following criteria:
• Age ≥ 18 years
• Histological diagnosis of invasive breast cancer
• Tumor size pT1-T3
• 0-3 positive axillary lymph nodes
• Histologically confirmed ER-positive tumors
• Histologically confirmed HER2-negative tumors and/or confirmed by in situ hybridization
• Dated and signed informed consent form (ICF)

Exclusion criteria

When any of the following is present the patient cannot participate:
• History of another malignant tumor within the last 5 years (except skin carcinoma, apart from melanoma).
• Neoadjuvant (preoperative) chemotherapy.
• Informed consent form (ICF) not dated / signed.

Endpoints

• Primary endpoints: OS, DRFS, LRFS at 5 and 10 years, by risk group.
• Patient or tumor characteristics that may affect treatment decision-making (age, menopausal status, histopathological features, etc.)
• Performance of EndoPredict in specific population subgroups.
• Disease outcome (OS, DRFS, LRFS) in special categories such as multicentric–multifocal disease, etc.

Study duration and timelines

• Study start: Q1 2025
• Patient enrollment period: 3 years
• Follow-up period: 10 years
• Study completion: Q4 2038