Practice Pearl #1 Introduction, Definition and Diagnosis of Neuroendocrine Tumors
A panel of experts in neuroendocrine tumors provide a definition of the disease and the diagnosis methods.
Daneng Li, MD: Hello, and welcome to this Directions in Oncology Pharmacy® Practice Pearls, titled “Best Practices for the Management of Neuroendocrine Tumors.” I am Daneng Li, codirector of the neuroendocrine tumor program in the Department of Medical Oncology and Therapeutics Research at City of Hope in Duarte, California.
Joining me today in this discussion are my colleagues Megan May, a clinical oncology pharmacy specialist at Baptist Health Lexington [Cancer Care Center] in Lexington, Kentucky, and Cecilia Lau, a clinical pharmacist specializing in GI [gastrointestinal] oncology at City of Hope in Duarte, California. We are going to discuss a number of topics pertaining to the best practices in the management of neuroendocrine tumors, including the role of somatostatin analogs and the challenges in providing optimal patient care. Let’s get started on our first topic. Cecilia, many individuals might not be familiar with the treatment of patients with neuroendocrine tumors. What are neuroendocrine tumors?
Cecilia Lau, RPh, BCOP, APh: Neuroendocrine tumors arise from neuroendocrine cells, which are located in many parts of the body. Neuroendocrine tumors, generally speaking, are relatively uncommon, but they can occur in any part of the body. They are found most commonly, however, in the pancreas, the GI tract, and the lungs. Neuroendocrine tumors are a group of heterogeneous diseases. Some are classified as dysfunctional and some as nonfunctional. Some of them are slow growing, but others can be aggressive. The management of neuroendocrine tumors can differ depending on the site of origin of a patient’s disease.
Daneng Li, MD: Neuroendocrine tumors are so fascinating because this type of tumor is such a heterogeneous disease. As a practitioner who sees patients with neuroendocrine tumors on a daily basis, [I think] they’re really separate tumors. It makes this a very complex diagnosis for patients.
Megan, I’m curious, because of that complexity, what the usual diagnostic process looks like. Can you enlighten us in terms of the tests, imaging, or other key things that patients may encounter when they’re trying to get worked up for this diagnosis?
Megan May, PharmD, BCOP: Most often, neuroendocrine tumors are found because of an incidental finding, or they may be suspected with clinical symptoms, like diarrhea. The appropriate diagnosis and treatment both require collaboration among multiple disciplines.
As Cecilia said, most neuroendocrine tumors are classified according to their organ origination. We have the foregut, midgut, and hindgut. How do we determine where it is? CT scans and MRIs are usually recommended for the initial evaluation. You can also do biochemical evaluation of serum and urine peptides depending on the primary site and the associated symptoms. An ultrasound can also provide initial diagnosis if the disease is metastatic when it’s found. An endoscopic ultrasound is preferred to diagnose, and you can also do a biopsy of the pancreatic area if it is involved. Obtaining tissue for pathology testing is also mandatory in order to have a confirmed diagnosis of neuroendocrine tumors.
Daneng Li, MD: Great. All those types of imaging modalities are really important for the diagnosis and initial management of someone that has a neuroendocrine tumor. We have also traditionally, and more recently, been inclined to use these functional imaging studies or nuclear medicine studies. Can you or Cecilia comment on these nuclear medicine scans, like the octreotide scan or maybe the newer gallium 68 [GA-68] dotatate PET [positron emission tomography] scan?
Cecilia Lau, RPh, BCOP, APh: The octreotide scan, I believe, utilizes the radio-labeled indium, indium 111, and the newer scan, the Gallium 68 dotatate, obviously, uses gallium 68. The gallium 68 PET scan, as I understand it, has a higher sensitivity, and these so-called functional imaging techniques can predict the patient’s response to somatostatin analogues, as well as the newer PRRT, the peptide receptor radionuclide therapy.
Daneng Li, MD: That is what makes neuroendocrine tumors unique from a diagnostic perspective; we have our traditional anatomic imaging that Megan mentioned in terms of ultrasounds, CT scans, and MRIs, which are so important in terms of characterizing the tumor bulk, changes, and size. Then we have this functional imaging in terms of the nuclear imaging that you’ve highlighted, which allows us to characterize whether the tumors express somatostatin receptors, for which we have therapies that specifically target those receptors, which we want to potentially take advantage of.