Recent advances in understanding and managing pituitary adenomas

Abstract

Pituitary adenomas (PAs) are common intracranial tumors. Despite their benign nature, PAs may cause a significant burden of disease, leading to either hormonal disturbances or local compression. A subset of PAs presents an aggressive behavior that remains difficult to predict, and in rare cases they metastasize. Therefore, early diagnosis and treatment are important. Advances in molecular pathology have improved the understanding of their pathogenesis and offer opportunities to identify and target novel pathways. Improved imaging and functional molecular techniques precisely detect even very small tumors and guide targeted treatment. Transsphenoidal surgery is the first-line treatment for the majority of PAs, and advances in the field of endoscopic neurosurgery offer excellent outcomes. Dopamine agonists (DAs) are traditionally the first-line treatment for prolactinomas. For patients with acromegaly, first- and second-generation somatostatin analogues (SSAs) are applied when surgery is not successful or not indicated. For Cushing's disease (CD), drugs targeting adrenal steroidogenesis, somatostatin receptors in the pituitary, and glucocorticoid receptors are used to treat hypercortisolism in patients with persistent or recurrent CD, for those who are not good surgical candidates, and as a bridge treatment for those who have undergone radiation treatment until cortisol levels are controlled. Temozolomide (TMZ) is the first-line chemotherapy for aggressive PAs, but new experimental therapies, like the anti-vascular endothelial growth factor (anti-VEGF) therapy, mechanistic target of rapamycin (mTOR) inhibitors, tyrosine kinase inhibitors, and cell cycle and checkpoint inhibitors, are now available. Radiotherapy is offered to patients with residual, recurrent, or progressive tumors. Modern techniques in radiotherapy planning and delivery are able to deliver high doses to the target tissue while sparing vital structures. As we familiarize ourselves with the biological behavior of PAs and our therapeutic armamentarium expands, the next goal is to tailor and personalize treatment to each individual patient so as to achieve the best outcome.

Keywords: Pituitary adenomas; medical treatment; radiotherapy; targeted systemic treatment; transsphenoidal neurosurgery; tumorigenesis.