New target therapies for patients with neuroendocrine tumors of the pancreas

Learning experiences with sunitinib continuous daily dosing in patients with pancreatic neuroendocrine tumours

Molecular strategies to improve outcomes for patients with pancreatic neuroendocrine tumours (nets) have focused on targeting vascular endothelial growth factor, platelet-derived growth factor, and mtor (the mammalian target of rapamycin). This approach has led to the regulatory approval of two molecularly targeted agents for advanced pancreatic nets: sunitinib, a multi-targeted tyrosine kinase inhibitor, and everolimus, an mtor inhibitor. Initial experience with sunitinib in advanced pancreatic net was gained from the phase iii registration trial, which used a continuous daily dosing (cdd) schedule instead of daily drug administration for 4 consecutive weeks every 6 weeks (schedule 4/2), the approved schedule for advanced renal cell carcinoma (rcc) and gastrointestinal stromal tumour (gist). Clinical experience gained with schedule 4/2 in rcc and gist shows that, using a therapy management approach, patients can start and be maintained on the recommended dose and schedule, thus optimizing treatment outcomes. Here, we discuss challenges that can potentially be faced by physicians who use sunitinib on the cdd schedule, and we use clinical data and real-life clinical experience to present therapy management approaches that support cdd in advanced pancreatic net.

Nonfunctional neuroendocrine tumor of the pancreas: Case report and review of the literature

INTRODUCTION

Pancreatic neuroendocrine tumors (PNET) have an incidence of one per 100,000 individuals per year. They represent about 1-2% of all pancreatic tumors. PNETs are a heterogeneous group with various clinical presentations and lineage. Non functional PNET (NF-PNET) are incidentally discovered in most cases. This article presents a review of NF-PNET and the case of a patient with this disease, in addition to its diagnosis, clinical presentation, and treatment.

PRESENTATION OF CASE

The patient is a 37-year-old asymptomatic man who was sent from his reference unit because of a pancreatic tumor that was visualized incidentally during a laparotomy performed three months before due to an acute abdomen secondary to blunt abdominal trauma. A CT scan was requested that showed a retroperitoneal mass 7.5cm×6.6cm×7cm with infiltration of the duodenal wall. Endoscopy was performed, which reported a duodenal ulcer with nonconclusive histological findings. A percutaneous biopsy was obtained out and a diagnosis of a neuroendocrine tumor was made. Chemotherapy was started because infiltration of the portomesenteric axis was suspected. The patient presented signs of toxicity during his third cycle and therefore was scheduled for exploratory laparotomy. Pancreatoduodenectomy was performed with a histologic diagnosis of a pancreatic neuroendocrine tumor.

DISCUSSION

The presentation of a NF-PNET is nonspecific. They continue to be tumors with a low incidence and few studies directed toward early detection and management have been carried out. Currently, CT scans are the studies most used for detection.

CONCLUSION

Surgical treatment is preferred in patients without evidence of unresectability with longer survival. The characteristics of NF-PNETs make their detection difficult and new strategies are needed for early detection and management. New studies in early stages with new cytotoxics or analogs are promising.