Management of Aggressive PitNETs: Evidence Gaps, Molecular Clues, and a Roadmap for Clinical Trials

Aggressive and metastatic pituitary neuroendocrine tumors constitute a rare yet biologically distinct group of lesions, marked by rapid growth, therapeutic resistance, and unpredictable clinical behavior. Despite their rarity, they contribute disproportionately to morbidity due to the absence of reliable prognostic and therapeutic frameworks. Recent evidence has reframed aggressiveness as a multidimensional process shaped by somatic variants, chromosomal instability, and epigenetic remodeling. Recurrent alterations in ATRX, TP53, and SF3B1, widespread copy number losses, and lineage-specific methylation and transcriptomic profiles help delineate tumors with early malignant potential. Single-cell and immune profiling studies reveal proliferative, migratory, and immunoevasive subpopulations that may underpin variable clinical trajectories and treatment responses. Clinically, temozolomide remains the only systemic therapy with consistent benefit, while immune checkpoint inhibitors, anti-VEGF agents, and peptide receptor radionuclide therapy show emerging efficacy in selected settings. Progress will rely on harmonizing diagnostic criteria, integrating molecular and imaging biomarkers, and embedding translational endpoints into clinical trials. Together, these advances define a path toward more precise recognition and management of aggressive pituitary tumors.