Building Consensus for Molecular Tumor Board Implementation in Europe: a Delphi procedure

Background: Molecular Tumor Boards (MTBs) integrate molecular and clinical data to guide precision oncology decisions. However, their structure and functioning remain highly heterogeneous across Europe. This study aimed to develop consensus-based policy recommendations to support their harmonized implementation. Methods: A two-round Delphi process was conducted among 17 European experts actively involved in MTBs. Questionnaire items were derived from a systematic and scoping review on the clinical impact and implementation aspects of MTBs. Experts rated items on a five-point Likert scale, with consensus predefined as a Content Validity Index (CVI) ≥ 80% of experts agreeing or strongly agreeing (scores 4-5). Results: Across two Delphi rounds, 76 items were evaluated. Thirty-six achieved consensus and were consolidated into 15 recommendations across four domains: organizational aspects (n = 8), testing (n = 3), inclusion criteria (n = 2), and clinical aspects (n = 2). Organizational standards emphasized the appointment of a referent clinician, the use of standardized digital submission tools, online meeting formats, and the integration of decision-support systems. The recommended MTB composition was multidisciplinary, including oncologists, molecular biologists, pathologists, geneticists, and other relevant specialists. In the testing domain, experts agreed that NGS should be the preferred approach for molecular profiling, conducted in certified laboratories, with variant interpretation supported by curated databases (e.g., ClinVar, COSMIC, OncoKB). Inclusion criteria prioritized patients with metastatic or rare diseases, ECOG performance status 0–2, life expectancy ≥12 weeks, and exhaustion of standard therapeutic options. Conclusions: This Delphi consensus produced 15 policy recommendations to standardize and sustain MTBs across Europe. These guidelines complement existing frameworks by providing practical operational guidance for precision oncology implementation.