Carcinoid and neuroendocrine tumors (NETs), including pancreatic neuroendocrine tumors and even more uncommon NETs such as goblet cell carcinoid and mixed adenocarcinomas, are discussed by a panel of medical experts in this new video series from OncLive TV.
The panel includes carcinoid/NET specialists Dr. Matthew Kulke (moderator, pictured below), Director of the Program in Neuroendocrine and Carcinoid Tumors, Dana-Farber/Brigham and Women’s Cancer and Associate Professor of Medicine at Harvard Medical School in Boston, Massachusetts; Dr. Rodney F. Pommier, Professor of Surgery and Surgical Oncologist, Oregon Health and Science University in Portland, Oregon; and Dr. James C. Yao, Associate Professor Department of Gastrointestinal Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center in Houston, Texas; as well as Dr. Pamela L. Kunz, Assistant Professor, Stanford School of Medicine in Stanford, California.
Please note: to see the videos below in a larger format, click on the YouTube logo in the bottom right corner of each video.
Neuroendocrine Tumors: Introduction and Overview is the first episode in the series. What are the differences in NETs? Dr. Pommier talks about the many types of neuroendocrine tumors and the differences between carcinoid and pancreatic neuroendocrine tumors. “There is so much terminology that confuses so many people,” says Dr. Pommier. There is a difference in the incidence between these groups with carcinoid tumors occurring annually in 1 in 100,000 people while pancreatic NETs occur in 1 in a million people. Do all carcinoids behave the same way? Dr. Yao notes that within carcinoid tumors the prognosis can vary significantly, with some tumors being far more aggressive than others. The presentation of these tumors varies as well and carcinoid tumors are not usually diagnosed until symptomatic.
What are the key characteristics when looking at a pathology report that tells the physician if the NET tumor is going to be slow-growing or more aggressive? The Histological Classification of Neuroendocrine Tumors, the second episode in the series, looks at the differences in the clinical behavior of NETs based on the site of origin and the biological characteristics of the cells. Dr. Kunz talks about using mitotic count and Ki67 to determine if NETs are indolent (slow-growing) or more aggressive and how tumors are determined to be low, intermediate, or high grade. These are important in determining how to treat a patient. Dr. Yao says it is important to consider if the tumors are malignant or benign. In the low-grade tumors, there is a question about which tumors could be considered benign. Tumor size is a key factor. According to Dr. Pommier, the primary site of the tumor plays a role in its aggressiveness. In the small bowel, tumors are generally considered malignant, even when they are small.
Biomarkers, blood and urine, are used for diagnosis, prognosis, and how to treat patients, says Dr. Yao. The Role of Biomarkers in Neuroendocrine Tumors is the third episode in the series. Dr. Yao selects biomarkers based upon how the patient is presenting. For a pancreatic neuroendocrine tumor, for example, he is guided by the symptoms to determine which biomarkers should be checked. These symptoms include hypoglycemia with weight gain, diarrhea and reflux, profound diarrhea, and a rash or diabetes. If carcinoid syndrome is suspected Dr. Yao uses the 5HIAA test to measure serotonin levels over a 24-hour period as part of the diagnostic workup but this marker alone is not enough to make a conclusive diagnosis. Dr. Pommier also targets biomarkers very specifically for each patient.
Dr. Pommier describes the Challenges in the Diagnosis of Neuroendocrine Tumors in the fourth episode of the series. He studied the records of 150 of his abdominal carcinoid patients to determine the length of time from presentation of symptoms to proper diagnosis. 96.5% of these patients received a NET diagnosis approximately 6.5 years after presenting with symptoms, with some patients waiting up to 20 years before being diagnosed. Dr. Pommier found approximately 35 initial diagnoses for these patients including Irritable Bowel Syndrome, lactose intolerant, and celiac sprue to the patient is “just plain crazy.” He attributes this delay in diagnosis to a combination of the lack of awareness by community physicians to the characteristics of the disease. “If you don’t suspect it, you can’t detect it.”