Hoag’s committed to accurate diagnosis, combined with progressive therapeutic options enables Hoag patients to achieve some of the highest clinical outcomes in the nation.



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Contact usNeuroendocrine tumors (NETs), or sometimes referred as islet cells, are abnormal growths in the endocrine glands. Since endocrine glands produce hormones, tumors of endocrine glands may also produce hormones. These hormones are often produced in excessive amounts by endocrine tumors and then released into the bloodstream, which can result in profound effects on the body.
Neuroendocrine tumors can be found all over the body. They are most commonly found in the abdomen, and are sometimes further classified as pancreatic neuroendocrine tumors (PNET), when found in the pancreas. PNETs are NETs that arise in the pancreas. They tend to have a slightly worse prognosis in comparison to NETs. Both PNETs and NETs tend to be slow growing tumors that are treatable even after they have metastasized.
Although NETs are much less common than most GI malignancies, SEER data (from 1973-2004) shows a dramatic 5-fold increase in diagnosed cases. Diagnosed incidence of NETs is predicted to continue rising at a faster rate than most other malignancies.
Neuroendocrine tumors can be benign or malignant. Whether benign or malignant, it is recommended to have all abdominal NETs surgically removed. At the time of resection/following surgery, the distinction of a benign or malignant tumor will be determined.
A way of classifying Neuroendocrine tumors is by the secretion of hormones from the tumor:
Non-functioning NETs: Patients with non-functioning tumors do not have any symptoms from excess secretion of pancreatic hormones since the tumor does not secrete any hormones into the blood.
Functional NETs: These tumors produce dramatic symptoms because of excess secretion of various different hormones such as insulin, gastrin, or glucagon.
Symptoms of neuroendocrine tumors depend on the type of tumor and its location, whether it produces excess hormones, how aggressive it is and whether it has spread to other structures in the body. NETs can be very difficult to diagnose and may take many years to grow to a size large enough to be seen in imaging scans or produce symptoms.
Up to half of all neuroendocrine tumors produce excess amounts of hormones that produce symptoms in the affected patient. For example, in patients with insulin producing NETs of the pancreas, excessive insulin decreases blood sugar levels so that symptoms of severe hypoglycemia develop. Whereas excessive hormones caused by other NETs may cause symptoms such as flushing, diarrhea, asthma and heart valve problems.
If neuroendocrine tumors are suspected, it’s important to seek proper evaluation and treatment from a healthcare expert experienced in the diagnosis and treatment of gastrointestinal issues.
Generally, the causes of neuroendocrine tumors are unknown. However, certain types of rare family syndromes have a higher risk of developing NETs, such as:
Multiple endocrine neoplasia type 1
Neurofibromatosis type 1
Von Hippel-Lindau syndrome (VHL)
Comprehensive evaluation with accurate diagnosis is the foundation for achieving successful outcomes. That’s why it’s important to seek care from a center that provides academic level care from a multidisciplinary, specialized team of hepatobiliary and pancreatic experts experienced in the accurate diagnosis of neuroendocrine tumors, as well as other complex gastrointestinal diseases.
Beginning with a thorough evaluation that includes a comprehensive physical exam, personal medical history review and state-of-the-art diagnostic workup, Hoag’s multidisciplinary team of board-certified, fellowship-trained hepatobiliary and pancreatic experts carefully evaluate and pinpoint the nature of the cancer, so the most appropriate personalized treatment options can be employed.
Hoag’s state-of-the-art diagnostic technologies provide our team with the latest modalities in the accurate diagnosis of neuroendocrine tumors and other disorders. Some of the progressive imaging studies that may be utilized include:
Tumor Markers are used to determine whether certain substances are being released into the blood. Tumor markers are often obtained to assess the probability of a cancer in a patient who has a lesion. While high tumor markers may indicate cancer, they are not definitive since non-cancerous conditions of the pancreas and liver can falsely elevate these tumor markers.
Octreotide Scanning is useful to localize a NET and for following patients after the surgery whose tumors were positive on octreotide scanning for detecting early recurrences.
Computed Tomography (CT) utilizes state-of-the-art x-rays to help determine the extent of the tumor and whether it involves surrounding organs.
Endoscopic Ultrasound (EUS) uses an ultrasound device placed within the digestive tract, which can help to better distinguish between neuroendocrine tumors and adenocarcinoma. The physician may also collect a sample of cells (biopsy) to aid in a definitive diagnosis.
Magnetic Resonance Imaging (MRI) is a test that uses magnetic waves to create detailed pictures of structures inside the body.
Positron Emission Tomography (PET) is used to identify malignant cells even before an actual lesion (lump) can be detected in a physical exam, or on a CT or MRI scan.
Laparoscopy is a minimally invasive surgical procedure used to examine internal organs by direct visualization. During the procedure, the surgeon can inspect the abdominal organs and insert other instruments to take tissue samples for a biopsy.
Biopsy is performed to definitively diagnose liver cancer, and may involve other methods outside of laparoscopic biopsy.
It’s important to note that proper diagnosis and staging of neuroendocrine tumors is critical to developing a successful treatment plan. That’s why it’s so important to seek proper evaluation and treatment from a healthcare expert experienced in the most advanced hepatobiliary and pancreatic care.
When it comes to neuroendocrine tumors and other gastrointestinal diseases, Hoag provides a full array of progressive treatment options. As a recognized leader and high-volume provider of innovative gastrointestinal care, Hoag’s multidisciplinary team of digestive disease experts performs some of the most advanced gastrointestinal procedures available in the nation with clinical outcomes that rival national figures.
Hoag continues to lead the way in complex GI care, providing access to a highly specialized surgical team that works collaboratively with Hoag-affiliated thoracic surgeons, gastroenterologists and medical oncology specialists to provide academic-level care. Hoag’s commitment to accurate diagnosis, combined with progressive therapeutic options enables Hoag patients to achieve some of the highest clinical outcomes in the nation.
To schedule a comprehensive diagnostic evaluation, or a second-opinion consultation with a Hoag gastroesophageal expert, call us at: 888-566-9712.
When it comes to neuroendocrine tumors and other gastrointestinal conditions, expert evaluation is vital to accurately diagnose and determine the best course of treatment for the individual patient.
At Hoag, our multidisciplinary team of experts includes academic-level hepatobiliary/pancreatic surgeons, medical oncologists, hepatologists and radiologists who work together to thoroughly review and determine the best treatment option suited to each individual patient. This emphasis on a collaborative, comprehensive approach to patient-centered care is why Hoag patient outcomes rank are among the nation’s best.
The treatment approach is the same for both functioning and non-functioning neuroendocrine tumors. NETs are often viewed as a chronic disease when more than one lesion is discovered during the diagnosis phase. NETs are often debulked such that greater than 90 percent of the disease is removed. Because these tumors are so slow-growing, often several years pass before another debulking surgery is required.
Hoag’s approach is to remove these tumors via a minimally invasive laparoscopic procedure, as often as possible. An open procedure is usually necessary in patients who have metastases, very large tumors (greater than 10 centimeters), or if there is invasion of the major blood vessels.
Some of the advanced surgical options for removal of non-functioning islet cell tumors of the pancreas include:
Enucleation pf PNET is a surgical procedure that carefully removes islet cell tumors without removing any pancreatic tissue. Hoag-USC surgeons have developed a laparoscopic technique for enucleation of pancreatic islet cell tumors, which provides a number of benefits to patients including a faster recovery and return to daily activities.
Laparoscopic/Robotic-Assisted Pancreatectomy is a minimally invasive surgical procedure where the body and tail of the pancreas is removed along with the spleen. However, Hoag-USC Surgical Center for Digestive Diseases routinely provides laparoscopic spleen-preserving pancreatectomy for patients with cystic tumors, neuroendocrine tumors and adenocarcinoma of the body and tail of the pancreas.
Central Pancreatectomy may be recommended for patients who have low-grade malignant or benign tumors in the neck of the pancreas. Removal of tumors in this area often requires removing a large portion of the pancreas. However, the experts at Hoag-USC Surgical Center for Digestive Diseases offer a highly specialized surgical procedure that removes only the tumorous portion of the neck of the pancreas, thereby preserving the head, body and tail of the pancreas.
The Whipple Operation involves resection (removal) of the head of the pancreas, a portion of the bile duct, the gallbladder and the duodenum. Occasionally, a portion of the stomach may also be removed. The Whipple Operation is often used to treat patients with adenocarcinoma of the pancreas, although it may be recommended for some patients with benign disorders such as chronic pancreatitis and benign tumors of the head of the pancreas. Laparoscopic Whipple is offered to patients with small confined tumors.
Hoag continues to lead the way in complex GI care, providing access to a highly specialized surgical team that works collaboratively with Hoag-affiliated thoracic surgeons, gastroenterologists and medical oncology specialists to provide academic-level care. Hoag’s commitment to accurate diagnosis, combined with progressive therapeutic options enables Hoag patients to achieve some of the highest clinical outcomes in the nation.
To schedule a comprehensive diagnostic evaluation, or a second-opinion consultation with a Hoag gastroesophageal expert, call us at: 888-566-9712.

Thomas Wang, M.D., Ph.D., is a board-certified surgical oncologist with the Hoag Family Cancer Institute and the medical director of the Hoag Melanoma/Advanced Skin Cancer Program. Dr. Wang comes to Hoag after spending the previous 15 years at the University of Alabama at Birmingham (UAB), where he served as a Professor of Surgery at the UAB School of Medicine and Chief of Surgical Oncology for the Birmingham VA Medical Center. He is a recognized author and researcher and has published over 40 original manuscripts in peer- reviewed scientific journals and ten book chapters. He has presented his clinical and basic science research at multiple national and international meetings. Dr. Wang is a graduate of Brown University and attended the Lewis Katz School of Medicine at Temple University. He completed his general surgery residency training at Drexel University College of Medicine/Hahnemann University Hospital and his surgical oncology fellowship at the University of Texas M.D. Anderson Cancer Center. Dr. Wang’s clinical interests include melanoma, soft tissue sarcomas and endocrine surgery. Dr. Wang is an active member on multiple national surgical societies, including the Association for Academic Surgery, the Society of University Surgeons, the American Association of Endocrine Surgeons and the Society of Surgical Oncology. In addition, since 2007, he is a panel member in the National Comprehensive Cancer Network, developing guidelines for the treatment of thyroid cancer.

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Dr. Michael Demeure is a fellowship trained endocrine surgeon and an internationally recognized expert in cancer surgery and research with particular expertise in endocrine, pancreatic, and gastrointestinal cancers. He has recently joined the Hoag community as the Medical Director for Precision Medicine.<br><br>He previously practiced in Scottsdale, Arizona His clinical focus is on tumors of the thyroid, parathyroid, adrenal glands, and pancreas. He has been recognized as a top surgeon in the Phoenix area and nationally. Dr. Demeure is a graduate of Hahnemann Medical College and completed his residency at the University of Arizona. He subsequently completed a fellowship in endocrine surgery in Perth, Australia and at the University of California, San Francisco. He previously held faculty positions at the Medical College of Wisconsin, as Professor and Chief of General Surgery at the University of Arizona, and most recently as Scientific Director, Center for Pancreatic and Endocrine Surgery, Scottsdale Healthcare, and Professor and Director of the Rare Tumors Program in the Division of Integrated Cancer Genomics, Translational Genomics Research Institute (TGen). In 2007, Dr. Demeure completed his Master’s Degree in Business Administration at the University of Arizona. Dr. Demeure is a past President of the American Association of Endocrine Surgeons, is regularly recognized as one “America’s Top Surgeons”, and has been named as on the “Best Doctors in America” every year since 2001.<br><br>While maintaining a very busy clinical practice and performing over 300 major operations annually, Dr. Demeure has led an active research lab for over 20 years with the majority of those efforts centered on using genomic technologies to develop novel biomarkers, new therapeutic targets, and related therapies in the management of endocrine and gastrointestinal cancers. His efforts has included his participation as a Co-or Principle Investigator on some of the landmark trials in these same areas. Dr. Demeure is the author or co-author of over 100 scholarly works and he has given over 150 invited lectures and presentations. As the chief of general surgery at the University of Arizona, he led the student clerkship to excellence recognized by the department winning an award as the best clerkship designated by graduating students. He led several quality programs and was responsible for recruiting. In the first 3 years in the role, he led the division to financial profitability from a recurring yearly deficit.<br><br>Dr. Demeure was born in New York City, New York and grew up in Pittsburgh, Pennsylvania. His father was from Belgium and his mother is from Argentina; as such Dr. Demeure speaks both Spanish and French in addition to English. He and his wife Sara have two daughters and a son. Dr. Demeure has a black belt in Taekwondo and is currently studying Kung Fu. His other interests include reading, cooking, photography, and skiing.

Ronald Wolf, M.D., F.A.C.S., is a board-certified surgical oncologist who specializes in treating liver, bile duct and pancreatic cancer at Hoag Family Cancer Institute. His clinical interests include pancreatic adenocarcinoma, colon and rectal cancers that have metastasized to the liver, surgical treatment for bile duct tumors and cysts and surgery for soft tissue sarcoma. Previously, Dr. Wolf served as Professor of Clinical Surgery in the Department of Surgery, Division of Hepatobiliary & Pancreas Surgery/Islet Cell Transplantation at UC Irvine School of Medicine and Long Beach Memorial Medical Center. Prior to that, he served as Medical Director of Hepatic and Pancreatic Surgery at Legacy Good Samaritan Medical Center in Portland, Oregon, and as the Medical Director of Liver and Pancreas Surgery at Providence Cancer Center, also in Portland. Dr. Wolf received his medical degree from Oregon Health & Science University in Portland, followed by an internship and two residencies in general surgery at UC Davis. He then completed a fellowship in surgical oncology at Memorial Sloan Kettering Cancer Center in New York, where he also served as a clinical research fellow. Later, he helped direct surgical resident and fellowship-level postgraduate training programs in Portland. Dr. Wolf has co-authored more than 80 clinical presentations throughout his career and is a committee member of several national organizations including the American College of Surgeons, the Society of Surgical Oncology and the AHPBA Americas Hepatopancreatobiliary Association.

<p>Tara Seery, M.D., attended University College Dublin School of Medicine followed by an internship at Mater Misericordiae Hospital as well as an internship and residency at Caritas St. Elizabeth Medical Center in Boston. She then completed fellowships in hematology/oncology at both Caritas St. Elizabeth Medical Center and University of Illinois at Chicago. Dr. Seery is board certified in Medical Oncology and Hematology.</p><p>Dr. Seery is particularly interested in GI oncology, including hepatobiliary cancers such as pancreatic, liver and bile duct cancers.</p><p>She has served as the primary investigator on several clinical research trials, co-authored numerous medical publications and abstracts, and edited multiple peer-reviewed journals. Additionally, she has given clinical presentations both across the U.S. and abroad. </p><p>Dr. Seery’s teaching experience spans the areas of medical and graduate level courses including a Hematology/Oncology Fellowship Annual Lecture Series on Pancreatic Cancer, Liver Cancer and the Management of Unresectable Hepatocellular Carcinoma at UC Irvine’s 5th Annual Gastroenterology and Hepatology Symposium. In addition, she oversaw a group of Hematology/Oncology Fellows at the University of California Irvine Outpatient Clinic.</p><p>Dr. Seery is a member of the American Society of Clinical Oncology and the American Society of Hematology.</p>
Hoag’s Precision Medicine Program combines genomics and genetics to diagnose, treat, and prevent diseases. Using the latest advances in genomic technologies, targeted therapies and research, our precision medicine program brings together a multidisciplinary team, including a robust genetic counseling group of experts, to provide patients with the latest in innovation and technology.
Being diagnosed with cancer can feel overwhelming at times. Many patients and their families need help with coping and can benefit from supportive counseling. Oncology Clinical Social Workers are available to provide emotional and practical support during all stages of cancer including diagnosis, treatment and post-treatment survivorship.
Hoag Family Cancer Institute dietitians work closely with patients’ physicians, nurses, therapists, and social workers to ensure complete care.