Abstract 134P
Background
MammaPrint (MP) and BluePrint (BP) signatures have been validated in the adjuvant setting to identify patients for which adjuvant chemotherapy (CT) could be spare. Neoadjuvant Chemotherapy (NCT) is a common approach for patients (pts) with clinically high-risk Early Breast Cancer (EBC). Other options include neoadjuvant endocrine therapy (NET) or primary surgery particularly for those patients with low-risk luminal tumors. In the DETERMIND study, we explore whether pre-operative use of MP/BP may help clinicians to reinforce the best treatment strategy for clinically high-risk patients.
Methods
DETERMIND is a prospective, open-label, multicenter study, assessing the utility of the MP/BP signature on the decision-making process of optimal therapy for patients with operable clinically high-risk HR+/HER2- EBC, stage II-IIIA (up to N1) and recommendation for NCT. A total of 165 pts have been included in 11 centers. Patient data will be collected at inclusion (baseline), and at the time of MP/BP results and at 1- and 3-years follow-up.
Results
This initial analysis includes the first 99 pts: Median age was 57 years (range 31-85), 94% were stage II, and 51% cN1. By MP/BP, 37 pts (37%) were classified as Luminal A, 58 (59%) as Luminal-B, and 4 cases presented as non-Luminal phenotype (3 Basal, 1 HER2). In line with MP/BP results, 44 pts did not receive NCT. In the MP/BP Luminal A group, 35 pts (95%) did not receive NCT, and for 19 pts it was replaced by NET. Patients with MP High-Risk received NCT in 53 cases (85%). The confidence on the final treatment decision by physicians and patients was significantly increased by the MP/BP result.
Conclusions
In clinical high-risk HR+/HER2- EBC pts with criteria for NCT there is a high prevalence (35%) of MP/BP Luminal A, who were able to de-escalate NCT. MP/BP also further supported decision to administered NCT in the majority (85%) of patients with MP High Risk. Our findings support the utility of MP/BP in high clinical risk HR+/HER2- EBC to guide neoadjuvant therapy decision and provide further information and confidence to clinicians and patients for shared-decision making.
Legal entity responsible for the study
FISABIO.
Funding
Agendia N.V.
Disclosure
A. Llombart Cussac: Financial Interests, Institutional, Project Lead: Agendia; Financial Interests, Personal, Expert Testimony: Agendia; Financial Interests, Personal, Invited Speaker: Agendia. All other authors have declared no conflicts of interest.