Endocrine Abstracts

Introduction: Pheochromocytomas(PCC) and paragangliomas(PGGLs) are rare neuroendocrine tumors. Management is very complex, this is why physicians involved in the management of these patients need to take into account not only clinical aspects but also genetics of these tumors. We present a group of patients diagnosed of metastatic PGG or PCC, their characteristics and long term follow-up.

Methods and design: Descriptive and unicentric study that includes 23 patients diagnosed with metastatic PCC/PGGLs, assessed at Hospital Universitari i Politècnic La Fe in Valencia, Spain between 2011 and 2022. Demographic, surgical, anatomopathological, clinical, imaging tests and treatments variables are included. Results are expressed as mean and standard deviation (SD) in the case of quantitative variables or percentage in the case of qualitative variables (SPSS 25.0).

Results: 55% of the patients were women. Mean age at diagnosis of the primary tumor was 39 years, and at diagnosis of the first metastasis was 45 years (SD 19). 86% where carriers of a mutation, 54.5% germinal mutation: SDHB 66.7%, SDHD 16.7%, AF2 8.3%, SDHA 8.3%. The 28% remaining had somatic line mutations: CSDE1 29%, NF1, EPAS1, FH, HRAS and VHL in 14.3% each. All of the cases underwent surgery. On the pathological study of the primary tumor all of the patients had at least one value of bad prognosis, with high risk of malignization potential in 8 cases (PASS and GAP scores more than 3 points). For follow up and treatment decision we utilized different imaging techniques: 68GalioPET-CT (100%) with positive uptake in 72.2% of cases, 123-MIBG (77.3%), 18FDG PET-CT (86.4%). The mean of treatment lines used in each patient was 2.7. Regarding systemic treatment: Somatostatin analogues were the most used (72.7%), followed by QT CVD (45.5%), Lu-DOTA-TATE (30%), MIBG (22%). Treatment with Lu-DOTA-TATE manages to stabilize the disease in more than 50% of cases (57.1%) with an average PFS of 21 months, with a partial response on hormonal secretion (PR) in more than 50%. Chemotherapy with CVD: 50% have a PR, 10% a CR in 10% of cases continues an ED. 50% of the metastatic PCC/PGGs treated with CVD were carriers of the SDHB mutation.

Conclsion: - Germline and somatic genetic studies are essential to guide the management of these patients.

- Treatment with Lu-DOTA-TATE seems effective in patients with positive uptake in Ga68-PET-CT with considerable PFS.

- Patients should be assessed within a multidisciplinary committee and framed in Reference Units, given their therapeutic complexity.