Current Advances in Papillary Craniopharyngioma: State-Of-The-Art Therapies and Overview of the Literature.

Craniopharyngiomas are commonly classified as low-grade tumors, although they may harbor a malignant behavior due to their high rate of recurrence and long-term morbidity. Craniopharyngiomas are classically distinguished into two histological types (adamantinomatous and papillary), which have been recently considered by the WHO classification of CNS tumors as two independent entities, due to different epidemiological, radiological, histopathological, and genetic patterns. With regard to papillary craniopharyngioma, a BRAF V600 mutation is detected in 95% of cases. This genetic feature is opening new frontiers in the treatment of these tumors using an adjuvant or, in selected cases, a neo-adjuvant approach. In this article, we present an overview of the more recent literature, focusing on the specificities and the role of oncological treatment in the management of papillary craniopharyngiomas. Based on our research and experience, we strongly suggest a multimodal approach combining clinical, endocrinological, radiological, histological, and oncological findings in both preoperative workup and postoperative follow up to define a roadmap integrating every aspect of this challenging condition.

A Somatostatin Receptor Subtype-3 (SST3) Peptide Agonist Shows Antitumor Effects in Experimental Models of Nonfunctioning Pituitary Tumors.

PURPOSE: Somatostatin analogues (SSA) are efficacious and safe treatments for a variety of neuroendocrine tumors, especially pituitary neuroendocrine tumors (PitNET). Their therapeutic effects are mainly mediated by somatostatin receptors SST2 and SST5. Most SSAs, such as octreotide/lanreotide/pasireotide, are either nonselective or activate mainly SST2. However, nonfunctioning pituitary tumors (NFPTs), the most common PitNET type, mainly express SST3 and finding peptides that activate this particular somatostatin receptor has been very challenging. Therefore, the main objective of this study was to identify SST3-agonists and characterize their effects on experimental NFPT models. EXPERIMENTAL DESIGN: Binding to SSTs and cAMP level determinations were used to screen a peptide library and identify SST3-agonists. Key functional parameters (cell viability/caspase activity/chromogranin-A secretion/mRNA expression/intracellular signaling pathways) were assessed on NFPT primary cell cultures in response to SST3-agonists. Tumor growth was assessed in a preclinical PitNET mouse model treated with a SST3-agonist. RESULTS: We successfully identified the first SST3-agonist peptides. SST3-agonists lowered cell viability and chromogranin-A secretion, increased apoptosis in vitro, and reduced tumor growth in a preclinical PitNET model. As expected, inhibition of cell viability in response to SST3-agonists defined two NFPT populations: responsive and unresponsive, wherein responsive NFPTs expressed more SST3 than unresponsive NFPTs and exhibited a profound reduction of MAPK, PI3K-AKT/mTOR, and JAK/STAT signaling pathways upon SST3-agonist treatments. Concurrently, SSTR3 silencing increased cell viability in a subset of NFPTs. CONCLUSIONS: This study demonstrates that SST3-agonists activate signaling mechanisms that reduce NFPT cell viability and inhibit pituitary tumor growth in experimental models that expresses SST3, suggesting that targeting this receptor could be an efficacious treatment for NFPTs.

Is Gross Total Resection Reasonable in Adults with Craniopharyngiomas with Hypothalamic Involvement?

OBJECTIVE: The treatment of hypothalamus-invading craniopharyngiomas, based on pediatric experience, is subtotal resection (STR) with radiotherapy. This strategy sometimes leads to uncontrollable tumor progression. In adults, with the use of endoscopic endonasal surgery (EES), does removing the hypothalamic part of the tumor-whenever possible-compromise the outcome of the patients? METHODS: We included adults with craniopharyngioma treated by a first EES in 2008-2016 by senior neurosurgeon (E.J.). Endocrine, ophthalmologic, and hypothalamic data were retrospectively collected, including body mass index (BMI), cognitive and social status, with a systematic follow-up interview. Magnetic resonance imaging scans were graded according to Puget classification: 0, no hypothalamic involvement; 1, hypothalamic displacement; and 2, hypothalamic involvement. Grade 2 tumors were separated into gross total resection (GTR) or STR. RESULTS: We included 22 patients aged 18-79 years. Presenting symptoms were visual (14, 64%), endocrine dysfunction (10, 45%), BMI >30 (8, 36%), and cognitive/psychiatric impairment (9, 41%). Fourteen (64%) were grade 2 craniopharyngiomas. GTR was performed in 14 (64%) patients. Postoperatively, 12/14 (86%) cases improved visually, and 20 (91%) needed hormone replacement therapy. There was no difference in BMI evolution in the GTR versus STR group, cognitive status was stable or improved in all patients except 1; 4/8 patients with STR experienced progression needing adjuvant treatment versus no patient with GTR. CONCLUSIONS: EES GTR of grade 2 craniopharyngiomas does not cause major hypothalamic worsening, in contrast with children operated by cranial approaches. The surgeon's experience is key in deciding when to stop the dissection. Offering GTR whenever possible aims at avoiding tumor progression and radiotherapy.

Pasireotide: A potential therapeutic alternative for resistant prolactinoma.

CONTEXT: About 10% of prolactinomas are resistant to dopamine-agonists (DAs). The only alternatives for tumor and prolactin control are surgery or radiotherapy. While studies on first generation somatostatin analogs have shown no efficacy against prolactinomas, no study has been conducted on the new multireceptor-targeted somatostatin receptor ligand pasireotide, which presents high affinity for 5, 3, 2 and 1 receptor subtypes. CASE DESCRIPTION: A 41 year-old woman presented with a macroprolactinoma showing resistance to all available DAs. She was first diagnosed at 17 years old after which she had undergone two incomplete debulking surgeries. Under pasireotide long-acting release (LAR) treatment, plasma prolactin levels normalized and symptoms disappeared within one month after initiation. The clinical benefits of the monotherapy (specifically, prolactin levels within normal range and stable tumor volume) were maintained for seven years. Glucose tolerance was satisfactory. Pathological analysis of the tumor revealed high SSTR5 and low SSTR2 expression (25 and 5% of cells respectively). CONCLUSION: This is a promising first report of a patient with a DA-resistant macroprolactinoma who achieved long-term control, in terms of prolactin normalization and tumor volume, under pasireotide treatment alone. Pasireotide could thus be an alternative in prolactinomas resistant to DA. SSTR expression analysis on pathology could guide patient selection.