Clinical decision making in small non-functioning VHL-related incidentalomas

Genetic background and intraoperative haemodynamic instability in patients with pheochromocytoma and paraganglioma: a multicentre retrospective study

BACKGROUND

Perioperative management to maintain intraoperative haemodynamic stability is crucial during surgical treatment of pheochromocytomas and paragangliomas (PPGLs). Although ~70% of PPGLs carry pathogenic variants (PVs) in susceptibility genes, whether intraoperative haemodynamic instability (IHI) is associated with genetic background remains unclear. This study aimed to analyse IHI in patients with PPGL due to PVs in different genes.

MATERIALS AND METHODS

This retrospective study recruited 756 patients with abdominal PPGL from two tertiary care centres. Clinical information including sex, age, catecholamine-associated signs and symptoms (CAS), tumour location and size, biochemistry, and perioperative characteristics were collected. Genetic mutations were investigated using next-generation sequencing.

RESULTS

Among the 671 patients included in the analysis, 61.8% (415/671) had IHI. IHI was significantly associated with genetic background in patients with PPGL. Most (80.9%, 89/110) patients with PPGL due to PVs in HRAS suffered IHI. In contrast, only half (31/62) of patients with PPGL due to PVs in VHL had IHI. In the multivariate regression analysis, compared to those with negative genetic testing results, patients with PPGL due to PVs in HRAS (OR 3.82, 95% CI 2.187-6.679, P <0.001), the other cluster 2 genes (OR 1.95, 95% CI 1.287-2. 569, P <0.05), and cluster 1 genes other than VHL (OR 2.35, 95% CI 1.338-4.111, P <0.05) were independent risk factors for IHI, while PVs in VHL was not independent risk factor (OR 1.09, 95% CI 0.605-1.953, P ≥0.05). In addition, age at diagnosis of the primary tumour, presenting of CAS, and tumour size were identified as independent factors for IHI. The nomogram illustrated that genetic background as sharing the largest contribution to IHI, followed by tumour size, age, and presentation of CAS.

CONCLUSION

IHI is associated with the genetic background in patients with PPGL. The perioperative management of patients with PPGL can be personalised according to their genetic backgrounds, tumour size, age, and presentation of CAS.

The Role of VHL in the Development of von Hippel-Lindau Disease and Erythrocytosis

Von Hippel-Lindau disease (VHL disease or VHL syndrome) is a familial multisystem neoplastic syndrome stemming from germline disease-associated variants of the VHL tumor suppressor gene on chromosome 3. VHL is involved, through the EPO-VHL-HIF signaling axis, in oxygen sensing and adaptive response to hypoxia, as well as in numerous HIF-independent pathways. The diverse roles of VHL confirm its implication in several crucial cellular processes. VHL variations have been associated with the development of VHL disease and erythrocytosis. The association between genotypes and phenotypes still remains ambiguous for the majority of mutations. It appears that there is a distinction between erythrocytosis-causing VHL variations and VHL variations causing VHL disease with tumor development. Understanding the pathogenic effects of VHL variants might better predict the prognosis and optimize management of the patient.