Clinical Predictors of Pseudohypoxia-Type Pheochromocytomas

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.

Intraoperative hemodynamic instability during laparoscopic adrenalectomy for pheochromocytoma without preoperative medical preparation compared with nonsecreting tumor

BACKGROUND

Control of hemodynamic features during adrenalectomy for pheochromocytoma is recommended to minimize perioperative cardiovascular complications. However, episodes of intraoperative hemodynamic instability have been observed during adrenalectomies with other indications than pheochromocytoma. The objective of this study was to compare the hemodynamic instability score assessed during unilateral adrenalectomy for pheochromocytoma without preoperative medical preparation to hemodynamic instability score in nonsecreting tumor.

METHODS

This was an observational study with prospective intraoperative hemodynamic data collection (every 20 seconds) and retrospective analysis.

RESULTS

During the study period, 60 consecutive patients (30 pheochromocytomas vs 30 nonsecreting tumors) were included with a median number of data collections during total procedure time of 318 (interquartile range, 257-388). Mean cumulative intraoperative time outside the target blood pressure range expressed as a percentage of total procedure time was 13.3% vs 6.8% for systolic blood pressure >160 mm Hg (P = .01) and 2.4% vs 2.8% for mean arterial pressure <60 mm Hg (P = ns), respectively. The median hemodynamic instability score during total procedure time was 33 (interquartile range, 27-43) and 20 (interquartile range, 11-26) in the pheochromocytoma and nonsecreting tumor group, respectively (P < .01). Hemodynamic instability score were similar in patients with compared with without long-term antihypertensive treatment in each patient group (P = ns). The mean length of hospital stay was 2.0 ± 1.5 days, and 30-day morbidity rate was 6.6% (4/60) with no significant difference observed between both groups.

CONCLUSION

Although intraoperative hemodynamic instability remains greater in the pheochromocytoma group without preoperative medical preparation, both groups have similar hypotensive episodes. These data highlight the need to better understand the role of preoperative medical preparation in pheochromocytoma patients.

Main mechanisms and clinical implications of alterations in energy expenditure state among patients with pheochromocytoma and paraganglioma: A review

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors with diverse clinical presentations. Alterations in energy expenditure state are commonly observed in patients with PPGL. However, the reported prevalence of hypermetabolism varies significantly and the underlying mechanisms and implications of this presentation have not been well elucidated. This review discusses and analyzes the factors that contribute to energy consumption. Elevated catecholamine levels in patients can significantly affect substance and energy metabolism. Additionally, changes in the activation of brown adipose tissue (BAT), inflammation, and the inherent energy demands of the tumor can contribute to increased resting energy expenditure (REE) and other energy metabolism indicators. The PPGL biomarker, chromogranin A (CgA), and its fragments also influence energy metabolism. Chronic hypermetabolic states may be detrimental to these patients, with surgical tumor removal remaining the primary therapeutic intervention. The high energy expenditure of PPGL has not received the attention it deserves, and an accurate assessment of energy metabolism is the cornerstone for an adequate understanding and treatment of the disease.

Development and internal validation of a novel predictive model for SDHB mutations in pheochromocytomas and retroperitoneal paragangliomas

Aim

To develop and internally validate a novel predictive model for SDHB mutations in pheochromocytomas and retroperitoneal paragangliomas (PPGLs).

Methods

Clinical data of patients with PPGLs who presented to Peking Union Medical College Hospital from 2013 to 2022 and underwent genetic testing were retrospectively collected. Variables were screened by backward stepwise and clinical significance and were used to construct multivariable logistic models in 50 newly generated datasets after the multiple imputation. Bootstrapping was used for internal validation. A corresponding nomogram was generated based on the model. Sensitivity analyses were also performed.

Results

A total of 556 patients with PPGLs were included, of which 99 had a germline SDHB mutation. The prediction model revealed that younger age of onset [Odds ratio (OR): 0.93, 95% CI: 0.91-0.95], synchronous metastasis (OR: 6.43, 95% CI: 2.62-15.80), multiple lesion (OR: 0.22, 95% CI: 0.09-0.54), retroperitoneal origin (OR: 5.72, 95% CI: 3.13-10.47), negative 131I-meta-iodobenzylguanidine (MIBG) (OR: 0.34, 95% CI: 0.15-0.73), positive octreotide scintigraphy (OR: 3.24, 95% CI: 1.25-8.43), elevated 24h urinary dopamine (DA) (OR: 1.72, 95% CI: 0.93-3.17), NE secretory type (OR: 2.83, 95% CI: 1.22- 6.59), normal secretory function (OR: 3.04, 95% CI: 1.04-8.85) and larger tumor size (OR: 1.09, 95% CI: 0.99-1.20) were predictors of SDHB mutations in PPGLs, and showed good and stable predictive performance with a mean area under the ROC curve (AUC) of 0.865 and coefficient of variation of 2.2%.

Conclusions

This study provided a novel and useful tool for predicting SDHB mutations by integrating easily obtained clinical data. It may help clinicians select suitable genetic testing methods and make appropriate clinical decisions for these high-risk patients.

Development and validation of a novel nomogram predicting pseudohypoxia type pheochromocytomas and paragangliomas

PURPOSE

Pseudohypoxia type (PHT) pheochromocytomas and paragangliomas (PPGLs) are more likely to metastasize and have a poor prognosis. However, application of genetic tests has many restrictions. The study aims to establish a novel nomogram for predicting the risk of PHT PPGLs.

METHODS

This retrospective cross-sectional study included 242 patients with pathology confirmed PPGLs in one tertiary care center in China in 2010-2021. Clinical and biochemical characteristics were collected. Next-generation sequencing was performed in all PPGLs patients for detection of mutation. Univariate and multivariable logistic regression analyses were used to select risk factors for constructing the nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the discrimination of the nomogram and the calibration curve was performed.

RESULTS

Four variables including age ≤ 35 years, hypertension, 24 h urinary output of urinary vanillylmandelic acid (VMA) ≥ 100 umol/24 h and urinary 17-ketosteroide (17 KS) ≤ 50 umol/24 h levels were independently associated with PHT PPGLs in the logistic regression analysis and were included in the nomogram. The nomogram showed a good discrimination performance with AUC of 0.829 [95% confidence interval (CI), 0.767-0.891] in the training set and 0.797 (95%CI, 0.659-0.935) in the validation set, respectively. The calibration curve showed a bias-corrected AUC of 0.809 vs. 0.795, and a Hosmer-Lemeshow (H-L) test yielded a p value of 0.801 vs. 0.885, indicating the nomogram's good ability to distinguish PHT PPGLs from non-PHT PPGLs.

CONCLUSION

Our study has proposed a novel nomogram for individualized prediction of the PHT PPGLs, which may make contributions to guide the patients' personalized management, follow-up, and treatment.