Functional Precision Medicine Successfully Guides Therapeutic Regimen of 'Cancer of Unknown Primary' Later Classified as Triple-Negative Breast Cancer: A Case Report.

Introduction: Controlled randomized trials, molecular analytics, and guideline recommendations have so far been irreplaceable tools to ensure appropriate treatment and decision-making for physicians and patients. Individual patient models are increasingly complementing these methods, particularly in the case of advanced cancers, rare cancers, and cancers of unknown primary (CUP), as in these cases comprehensive clinical evidence is unavailable, often resulting in poor treatment success, even after stratification.

Case Presentation: Here we report a 53-year-old patient with CUP with axillary lymph node metastases for whom patient-derived 3D (PD3D) tumor organoids successfully guided personalized treatment.