Follow-up Recommendations for Completely Resected Gastroenteropancreatic Neuroendocrine Tumors

Abstract

There is no consensus on optimal follow-up for completely resected gastroenteropancreatic neuroendocrine tumors. Published guidelines for follow-up are complex and emphasize closer surveillance in the first 3 years after resection. Neuroendocrine tumors have a different pattern and timescale of recurrence, and thus require more practical and tailored follow-up. The Commonwealth Neuroendocrine Tumour Collaboration convened an international multidisciplinary expert panel, in collaboration with the North American Neuroendocrine Tumor Society, to create patient-centered follow-up recommendations for completely resected gastroenteropancreatic neuroendocrine tumors. This panel used the RAND/UCLA (University of California, Los Angeles) Appropriateness Method to generate recommendations. A large international survey was conducted outlining current the surveillance practice of neuroendocrine tumor practitioners and shortcomings of the current guidelines. A systematic review of available data to date was supplemented by recurrence data from 2 large patient series. The resultant guidelines suggest follow-up for at least 10 years for fully resected small-bowel and pancreatic neuroendocrine tumors and also identify clinical situations in which no follow-up is required. These recommendations stratify follow-up strategies based on evidence-based prognostic factors that allow for a more individualized patient-centered approach to this complex and heterogeneous malignant neoplasm.

Gastroenteropancreatic Neuroendocrine Tumors

“…Given their high proliferative activity and low expression of SSTRs, poorly differentiated NETs are commonly imaged by 18 F‐fluorodeoxyglucose PET/CT. In well‐differentiated NETs 18 F‐fluorodeoxyglucose PET uptake can correlate negatively with prognosis; however, the use of this imaging modality is not routinely recommended …”

“…However, potential benefits and costs of such an approach should be carefully weighted in the context of a usually indolent disease. Postoperative imaging surveillance of radically resected GEP‐NETs can be performed at intervals ranging from every 6 months to every 2 years, depending on the biologic aggressiveness of the neoplasm, as determined by the Ki‐67 index, mitotic activity, degree of differentiation, presence of lymphovascular or perineural invasion, clearance of margins, and quality of the surgery performed . Cross‐sectional imaging (CT or MRI) is considered standard, whereas the routine use of functional imaging is not endorsed .…”

“…Postoperative imaging surveillance of radically resected GEP‐NETs can be performed at intervals ranging from every 6 months to every 2 years, depending on the biologic aggressiveness of the neoplasm, as determined by the Ki‐67 index, mitotic activity, degree of differentiation, presence of lymphovascular or perineural invasion, clearance of margins, and quality of the surgery performed . Cross‐sectional imaging (CT or MRI) is considered standard, whereas the routine use of functional imaging is not endorsed . Because recurrences can occur many years after the diagnosis, long‐term follow‐up (5‐10 years) is advisable for both pNETs and small bowel carcinoids.…”

“…Because recurrences can occur many years after the diagnosis, long‐term follow‐up (5‐10 years) is advisable for both pNETs and small bowel carcinoids. Surveillance beyond 10 years can be considered in individualized patients, considering the low and decreasing risk of recurrence at that point …”

Lung Metastases in Patients with Well-Differentiated Gastroenteropancreatic Neuroendocrine Neoplasms: An Appraisal of the Validity of Thoracic Imaging Surveillance

“…Two randomized control studies and a Cochrane meta-analysis of patients with colorectal cancer demonstrated no OS benefit with a more stringent follow-up protocol including thoracic cross-sectional imaging after surgery [19-21]. Nevertheless, recent recommendations on post-treatment surveillance of resected GEP-NENs based on the risk stratification of established prognostic factors allow for a more individualized, patient-tailored approach [22]. In the light of this knowledge and taking into consideration the indolent but still unpredictable nature of GEP-NENs with a different timescale and pattern to progression, risk stratification for surveillance for the majority of stage IV GEP-NEN patients, particularly those without extrahepatic metastases, can be used to identify patients at a high risk of developing LM.…”