neoAGORA: Exploring Clinical Utility of Serial Liquid Biopsy (ctDNA) in Patients With Early-Stage Breast Cancer

Study Rationale: Neoadjuvant therapy (NAT) is a standard treatment approach for patients with early-stage breast cancer (EBC), its benefits extend beyond enabling breast conserving surgery: it provides an early dynamic assessment of treatment sensitivity and creates an in vivo framework to interrogate tumor biology under therapeutic pressure. Pathological complete response (pCR) is an established surrogate marker of prognosis, particularly in triple negative (TN) and Human Epidermal Growth Factor Receptor 2(HER2)-positive breast cancer; however, the ability to predict response early during treatment and to identify patients at risk of residual disease or relapse remains limited. Circulating tumor DNA (ctDNA) has emerged as a promising minimally invasive biomarker for monitoring tumor burden and treatment response in real time. Previous studies have shown that baseline ctDNA levels, early ctDNA clearance during NAT, and postoperative ctDNA detection are associated with treatment response, minimal residual disease (MRD), and relapse risk. Nevertheless, the clinical utility of ctDNA across breast cancer subtypes and its integration into routine clinical decision-making remain incompletely defined. The neoAGORA study aims to evaluate subtype-specific ctDNA dynamics during standard NAT and to investigate their relationship with clinical outcomes, pathological response, advanced imaging findings, and digital pathology assessments. By integrating these complementary sources of information, the study seeks to improve response assessment and support the development of personalized management strategies for patients with EBC. Study design: The neoAGORA study is a multicenter observational study designed to investigate the value of liquid biopsy technologies in patients with EBC receiving standard neoadjuvant therapy. The study will include patients with luminal, HER2-positive, and TN tumors treated according to routine clinical practice. The neoAGORA prospective cohort will systematically collect clinical data, biological samples, and imaging information throughout treatment and follow-up. Serial blood samples will be collected at predefined time points before, during, and after neoadjuvant therapy, as well as tumor samples obtained at diagnosis, during treatment when available, at surgery, and at disease relapse. In addition, detailed clinical data will be collected, including demographic and clinical characteristics, treatments administered, radiological response, pathological response, and recurrence and survival outcomes. The study will incorporate a centralized biorepository and a common infrastructure for standardized collection of data and biological samples, enabling the evaluation of liquid biopsy-derived biomarkers, digital pathology, and advanced imaging in a real-world clinical setting. At least 300 patients (approximately 100 per breast cancer subtype) are expected to be enrolled. The platform is designed to allow future cohort expansions and to facilitate collaborative research aimed at evaluating the clinical utility of novel biomarkers and personalized medicine strategies in EBC. Study population and length of study: The neoAGORA study is a continuous recruitment study that will remain open indefinitely. The first cohort will include at least 300 patients, distributed evenly across the main breast cancer tumor subtypes. Recruitment of this cohort is expected to be completed in approximately 18 months. All participants will be followed for a minimum of 5 years after surgery. The study completion date for this cohort will be defined as the last visit of the last patient enrolled, resulting in an estimated total study duration of approximately 7 years from the inclusion of the first patient.