Breast carcinoma with neuroendocrine differentiation: a personalized therapeutic approach using somatostatin analogs

Breast carcinomas with neuroendocrine differentiation represent a rare and heterogeneous entity, associated with diagnostic and therapeutic challenges, particularly in the metastatic setting. We report the case of a 70-year-old woman with metastatic breast carcinoma, hormone receptor-positive and human epidermal growth factor receptor-2-negative, with histologically confirmed neuroendocrine differentiation and somatostatin receptor expression documented by 68Ga-DOTANOC positron emission tomography (PET-DOTANOC) positron emission tomography. The patient initiated treatment with letrozole and palbociclib, followed by the addition of octreotide, achieving a complete clinical and radiological response that was maintained throughout follow-up. This case highlights the importance of comprehensive histological, molecular, and functional characterization, enabling a personalized therapeutic approach. The combination of somatostatin analogs with endocrine therapy and cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors may represent an effective strategy in selected patients with breast carcinoma with neuroendocrine differentiation.