RESUMO
BACKGROUND: Central nervous system hemangioblastomas are the most prevalent manifestation of von Hippel-Lindau (VHL) disease and remain the main cause of mortality. Surgical resection is the primary treatment strategy, but is not always possible, and should be used as restrictively as possible. There is an unmet need for less invasive treatment strategies, such as targeted therapy. Expression of somatostatin receptor 2A (SSTR2A) in VHL-related hemangioblastomas has been described earlier, but the extent of expression in a larger population has yet to be determined. The authors hypothesize that a substantial subset of VHL-related hemangioblastomas show SSTR2A expression, which may serve as a potential new treatment target. METHODS: Patients who were surgically treated for a VHL-related hemangioblastoma from 1990 until 2021 at the UMC Utrecht were included. Clinical data was derived from a clinical database. Tissue samples were histopathologically examined with use of hematoxylin and eosin staining, and immunohistochemical analysis of SSTR2A expression was performed. RESULTS: Forty-three tissue samples were obtained from 26 patients. Nine showed strong positivity for SSTR2A expression, whereas 13 showed moderate and 15 sparse expression. Three samples showed no expression of SSTR2A. The distribution showed right-skewedness favoring a strong expression. SSTR2A expression colocalized with endothelial markers and not with stromal cells. Additionally, within-patient variability for SSTR2A expression was described in 14 patients. CONCLUSION: SSTR2A is expressed in varying degrees in the majority of VHL-related hemangioblastomas. Future treatment with somatostatin analogues or even peptide receptor radionuclide treatment may be considered for SSTR2A-positive cases.
RESUMO
Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multi-organ neoplasms. Among the manifestations of VHL are pancreatic neuroendocrine neoplasms (panNENs). In order to detect these lesions in a timely manner, patients are enrolled in a surveillance program, in accordance with the several existing VHL guidelines. However, these guidelines remain unclear about the role of biomarkers in diagnosing panNENs, despite the benefits a biomarker may offer regarding early detection of new lesions, thereby possibly limiting radiation exposure, and improving quality of life. The aim is to determine which biomarkers might be available in VHL patients and to assess their clinical relevance in diagnosing panNENs in VHL patients. We searched the databases of PubMed/Medline, Embase, and Web of Science to identify relevant articles. Seven studies assessing the diagnostic or prognostic value of biomarkers were included. The results from these studies were conflicting. Since no evident association between VHL-related panNENs and biomarkers was established in studies with larger study populations, currently biomarkers do not play a significant role in early detection or follow-up for panNENs in VHL patients. The absence of evidence underscores the need for specific research to address this unmet need.
RESUMO
Pancreatic neuroendocrine tumors (pNETs) in Von Hippel-Lindau (VHL) disease have a relatively good prognosis. However, a subset of pNETs metastasize and significantly contribute to VHL-related mortality. Evidence-based guidelines are needed for timely detection, management and intervention of these tumors. However, the value of several diagnostic tools is controversial, and evidence-based management strategies are lacking. This systematic review aims to update current literature on diagnostic and management strategies of pNETs in VHL and proposes evidence-based recommendations. The databases of PubMed/Medline, Embase and Web of Science were systematically searched to identify relevant studies. Studies were screened independently and cross-checked by two authors to assess eligibility for inclusion. Eighty-four articles were eligible for full text reading, and thirteen were critically appraised using the modified Quality Assessment of Diagnostic Accuracy Studies or modified Quality in Prognostic Studies tool. Six studies assessed the diagnostic value of imaging modalities, five focused on the optimal timing for surgical intervention, and one article studied the growth rate of pNETs. Quality of the available evidence was determined using the Grading of Recommendations, Assessment, Development and Evaluations tool. Studies recommended CT or MRI as the primary screening modalities for pNETs. For detection of metastases, 68Gallium-DOTATATE/TOC PET/CT is advised. For pNETs <2 cm a watch-and-wait approach is recommended, while for pNETs ≥2.5 cm surgical resection is advised. Due to limited data, no strong recommendations on surveillance could be proposed.