Somatostatin Analogs in Pancreatic Neuroendocrine Tumors

Several factors should be considered when evaluating the need for systemic therapy as a treatment for patients with pancreatic neuroendocrine tumors (NETs), including tumor grade, extent of disease, rate of disease growth, and primary site, states Pamela L. Kunz, MD. An asymptomatic patient with newly diagnosed metastatic disease that is well differentiated may undergo active surveillance, while an individual with bulky disease and symptoms should begin treatment, describes Kunz.

Somatostatin analogs, such as octreotide and lanreotide, are commonly used as first-line treatments for patients with pancreatic NETs says Diane Reidy-Lagunes, MD. Both agents are very similar in efficacy and have comparable mechanisms of action. Common adverse events associated with these agents include diarrhea and cramping, which with the inhibition of pancreatic exocrine function and gallbladder emptying, particularly after consumption of fatty foods, explains Rodney Pommier, MD. Supplementing with pancreatic enzymes can help mitigate diarrhea.

It is important to ascertain whether the diarrhea is worse before or after the injection, comments J. Philip Boudreaux, MD. Diarrhea that is worse 4 or 5 days prior to somatostatin analog administration may indicate that the drug is subtherapeutic and that hormonal symptoms are taking over. If the diarrhea worsens post-injection, the symptoms are likely due to pancreatic insufficiency.

Other adverse events associated with somatostatin analogs include elevated blood sugar, increased blood pressure, and dizziness. Additionally, these treatments can cause cholestasis and lead to gallstone formation. As a result, the gallbladder should be removed when performing liver metastasectomy, adds Pommier.