Perioperative management of hypertensive neuroblastoma: A study from the Italian Group of Pediatric Surgical Oncologists (GICOP)

Prevention and management of hypertensive crises in children with pheochromocytoma and paraganglioma

Hypertensive crises in pediatric patients are rare conditions. However, determining their precise prevalence is more challenging than in adults due to the heterogeneity in the definition itself. These crises frequently occur without a prior diagnosis of hypertension and may indicate an underlying cause of secondary hypertension, including pheochromocytoma/paraganglioma (PPGL). The mechanisms of hypertensive crises in the pediatric population with PPGL are directly related to different types of catecholamine excess. Noradrenergic tumors typically present with sustained hypertension due to their predominant action on α1-adrenoceptors in the vasculature. Conversely, adrenergic tumors, through epinephrine binding to β2-adrenoceptors in addition to stimulation of α1- and α2-adrenoceptors, more frequently cause paroxysmal hypertension. Furthermore, the biochemical phenotype also reflects the tumor localization and the presence of a genetic mutation. Recent evidence suggests that more than 80% of PPGL in pediatric cases have a hereditary background. PPGL susceptibility mutations are categorized into three clusters; mutations in cluster 1 are more frequently associated with a noradrenergic phenotype, whereas those in cluster 2 are associated with an adrenergic phenotype. Consequently, the treatment of hypertensive crises in pediatric patients with PPGL, reflecting the underlying pathophysiology, requires first-line therapy with alpha-blockers, potentially in combination with beta-blockers only in the case of tachyarrhythmia after adequate alpha-blockade. The route of administration for treatment depends on the context, such as intraoperative or pre-surgical settings, and whether it presents as a hypertensive emergency (elevated blood pressure with acute target organ damage), where intravenous administration of antihypertensive drugs is mandatory. Conversely, in cases of hypertensive urgency, if children can tolerate oral therapy, intravenous administration may initially be avoided. However, managing these cases is complex and requires careful consideration of the selection and timing of therapy administration, particularly in pediatric patients. Therefore, facing these conditions in tertiary care centers through interdisciplinary collaboration is advisable to optimize therapeutic outcomes.

Alpha-1 Adrenergic Antagonists Sensitize Neuroblastoma to Therapeutic Differentiation

Neuroblastoma (NB) is an aggressive childhood tumor, with high-risk cases having a 5-year overall survival probability of approximately 50%. The multimodal therapeutic approach for NB includes treatment with the retinoid isotretinoin (13-cis retinoic acid; 13cRA), which is used in the post-consolidation phase as an antiproliferation and prodifferentiation agent to minimize residual disease and prevent relapse. Through small-molecule screening, we identified isorhamnetin (ISR) as a synergistic compound with 13cRA in inhibiting up to 80% of NB cell viability. The synergistic effect was accompanied by a marked increase in the expression of the adrenergic receptor α1B (ADRA1B) gene. Genetic knockout of ADRA1B or its specific blockade using α1/α1B adrenergic antagonists led to selective sensitization of MYCN-amplified NB cells to cell viability reduction and neural differentiation induced by 13cRA, thus mimicking ISR activity. Administration of doxazosin, a safe α1-antagonist used in pediatric patients, in combination with 13cRA in NB xenografted mice exerted marked control of tumor growth, whereas each drug alone was ineffective. Overall, this study identified the α1B adrenergic receptor as a pharmacologic target in NB, supporting the evaluation of adding α1-antagonists to the post-consolidation therapy of NB to more efficiently control residual disease.

SIGNIFICANCE

Targeting α-adrenergic receptors synergizes with isotretinoin to suppress growth and to promote differentiation of neuroblastoma, revealing a combinatorial approach for more effective management of the disease and prevention of relapse.

Perioperative hypertension and anesthetic management in patients undergoing resection of neuroblastoma

INTRODUCTION

Neuroblastoma is the most common extracranial pediatric tumor, accounting for 5-8% of all childhood cancers. Neuroblastomas arise from catecholamine-secreting neural crest cells and their metabolites, vanillylmandelic acid and homovanillic acid, that are readily detected in urine. Although rarely seen in clinical practice, case reports exist documenting severe intraoperative hypertension. However, data on the incidence of intraoperative hypertension are lacking.

METHODS

This report is a single-center retrospective review of patients with neuroblastoma who underwent surgical resection (n = 102) at Boston Children's Hospital from July 1, 2012 to February 28, 2021. Significant intraoperative hypertension was defined as maximum systolic blood pressure greater than 95th percentile +12 mmHg based on normative blood pressure data. Statistical analysis was performed using Fisher's exact test, Wilcoxon rank-sum test, and logistic regression.

RESULTS

The overall incidence of intraoperative hypertension was 13% (n = 13/102). Higher American Society of Anesthesiologists (ASA) physical status was associated with intraoperative hypertension. Antihypertensive medications were administered intraoperatively in 9% of cases (n = 9), and the use was significantly associated with intraoperative hypertension. Of patients with preoperative urine catecholamine data (n = 82), all 10 patients who had intraoperative hypertension were noted to have elevated preoperative urine catecholamines. Intraoperative hypertension was not associated with postoperative hypertension, postoperative hypotension, or increased intensive care unit length of stay.

DISCUSSION/CONCLUSION

Intraoperative hypertension in patients with neuroblastoma remains a relatively uncommon occurrence; however, it does occur at a frequency higher than previously described. While intraoperative hypertension is associated with an increased use of antihypertensive medications in the operating room, it is not associated with adverse perioperative outcomes.

Cardiometabolic Health After Pediatric Cancer Treatment: Adolescents Are More Affected than Children

This cross-sectional study aimed at comparing the cardiometabolic (CM) health of children and adolescents and identifying factors associated with CM complications shortly after cancer treatment. Cancer-related characteristics, blood pressure (BP), anthropometry, and biochemical parameters were collected in 80 patients (56.3% female, mean age: 11.8 years; range: 4.5 - 21.0) a mean of 1.4 years following therapy completion. Compared to children, adolescents had higher mean z-score of insulin (-0.47 vs. 0.20; P = 0.01), HOMA-IR (-0.40 vs. 0.25; P = 0.02), waist-to-height ratio (0.36 vs. 0.84; P = 0.01), subscapular skinfold thickness (-0.19 vs. 0.47; P = 0.02), total body fat (-1.43 vs. 0.26; P < 0.01), and lower mean z-score of HDL-C (0.07 vs. -0.53; P < 0.01). Adolescents were more likely to have high BP (42% vs. 15%; P < 0.01), dyslipidemia (64% vs. 15%; P < 0.001), and cumulating ≥ 2 CM complications (42% vs. 2%; P < 0.001) than children. Adiposity indices (z-scores) were associated with high BP [odds ratio (OR) ranging from 2.11 to 4.09] and dyslipidemia (OR ranging from 2.06 to 4.34). These results suggest that adolescents have a worse CM profile than children shortly after therapy and that adiposity parameters are associated with CM complications, highliting the importance to develop intervention strategies targeting this population.

Low number of neurosecretory vesicles in neuroblastoma impairs massive catecholamine release and prevents hypertension

INTRODUCTION

Neuroblastoma (NB) is a pediatric cancer of the developing sympathetic nervous system. It produces and releases metanephrines, which are used as biomarkers for diagnosis in plasma and urine. However, plasma catecholamine concentrations remain generally normal in children with NB. Thus, unlike pheochromocytoma and paraganglioma (PHEO/PGL), two other non-epithelial neuroendocrine tumors, hypertension is not part of the usual clinical picture of patients with NB. This suggests that the mode of production and secretion of catecholamines and metanephrines in NB is different from that in PHEO/PGL, but little is known about these discrepancies. Here we aim to provide a detailed comparison of the biosynthesis, metabolism and storage of catecholamines and metanephrines between patients with NB and PHEO.

METHOD

Catecholamines and metanephrines were quantified in NB and PHEO/PGL patients from plasma and tumor tissues by ultra-high pressure liquid chromatography tandem mass spectrometry. Electron microscopy was used to quantify neurosecretory vesicles within cells derived from PHEO tumor biopsies, NB-PDX and NB cell lines. Chromaffin markers were detected by qPCR, IHC and/or immunoblotting.

RESULTS

Plasma levels of metanephrines were comparable between NB and PHEO patients, while catecholamines were 3.5-fold lower in NB vs PHEO affected individuals. However, we observed that intratumoral concentrations of metanephrines and catecholamines measured in NB were several orders of magnitude lower than in PHEO. Cellular and molecular analyses revealed that NB cell lines, primary cells dissociated from human tumor biopsies as well as cells from patient-derived xenograft tumors (NB-PDX) stored a very low amount of intracellular catecholamines, and contained only rare neurosecretory vesicles relative to PHEO cells. In addition, primary NB expressed reduced levels of numerous chromaffin markers, as compared to PHEO/PGL, except catechol O-methyltransferase and monoamine oxidase A. Furthermore, functional assays through induction of chromaffin differentiation of the IMR32 NB cell line with Bt2cAMP led to an increase of neurosecretory vesicles able to secrete catecholamines after KCl or nicotine stimulation.

CONCLUSION

The low amount of neurosecretory vesicles in NB cytoplasm prevents catecholamine storage and lead to their rapid transformation by catechol O-methyltransferase into metanephrines that diffuse in blood. Hence, in contrast to PHEO/PGL, catecholamines are not secreted massively in the blood, which explains why systemic hypertension is not observed in most patients with NB.

The Role of Oxidative Stress and Inflammation in Cardiometabolic Health of Children During Cancer Treatment and Potential Impact of Key Nutrients

Significance: The 5-year survival rate of childhood cancers is now reaching 84%. However, treatments cause numerous acute and long-term side effects. These include cardiometabolic complications, namely hypertension, dyslipidemia, hyperglycemia, insulin resistance, and increased fat mass. Recent Advances: Many antineoplastic treatments can induce oxidative stress (OxS) and trigger an inflammatory response, which may cause acute and chronic side effects. Critical Issues: Clinical studies have reported a state of heightened OxS and inflammation during cancer treatment in children as the result of treatment cytotoxic action on both cancerous and noncancerous cells. Higher levels of OxS and inflammation are associated with treatment side effects and with the development of cardiometabolic complications. Key nutrients (omega-3 polyunsaturated fatty acids, dietary antioxidants, probiotics, and prebiotics) have the potential to modulate inflammatory and oxidative responses and, therefore, could be considered in the search for adverse complication prevention means as long as antineoplastic treatment efficiency is maintained. Future Directions: There is a need to better understand the relationship between cardiometabolic complications, OxS, inflammation and diet during pediatric cancer treatment, which represents the ultimate goal of this review. Antioxid. Redox Signal. 35, 293-318.

Operative management and outcome in children with pheochromocytoma

OBJECTIVE

This study aimed to evaluate management and prognosis in children with pheochromocytoma who were treated at an Egyptian tertiary center.

METHODS

The authors conducted an 8-year retrospective analysis for 17 patients who were presented from January 2013 to January 2021. Clinical criteria, operative details, and follow-up data were assessed. Overall (OS) and event-free survival (EFS) were estimated by the Kaplan-Meier method. An event was assigned with the occurrence of recurrence or metachronous disease, or death.

RESULTS

Median age at diagnosis was 14 years (range: 6-17.5 years). Ten patients (58.8%) were males and seven (41.2%) were females. Hypertension-related symptoms were the main presentations in 15 patients (88%). None of the included children underwent genetic testing. Sixteen patients (94%) had unilateral tumors (right side: 12), whereas only one was presented with bilateral masses. The median tumor size was 7 cm (range: 4-9 cm). Metastatic workup did not reveal any metastatic lesions. All patients underwent open adrenalectomy, and clinical manifestations were completely resolved after surgery. Adjuvant therapy was not administered to any patient. There were no deaths or relapses at a median follow-up time of 40 months, whilst two children had metachronous disease after primary resection. Both were managed by adrenal-sparing surgery, and they achieved a second complete remission thereafter. Five-year OS and EFS were 100% and 88%, respectively.

CONCLUSIONS

Complete surgical resection achieves excellent clinical and survival outcomes for pheochromocytoma in children. Meticulous, long-term follow-up is imperative for early detection of metachronous disease to facilitate adrenal-sparing surgery. Genetic assessment for patients and their families is essential; however, it was not available at our institution.

Anesthesia in Children with Neuroblastoma, Perioperative and Operative Management

Neuroblastoma (NB) is the most common extracranial, solid, pediatric malignancy and, despite the constant progress of treatment and development of innovative therapies, remains a complex, challenging disease causing major morbidity and mortality in children. There is significant variability in the management of neuroblastoma, partially due to the heterogeneity of the clinical and biological behavior, and partially secondary to the different approaches between treating institutions. Anesthesia takes an integral part in the multidisciplinary care of patients with NB, from diagnosis to surgery and pain control. This paper aims to review and discuss the critical steps of the perioperative and operative management of children undergoing surgery for neuroblastoma. Anesthesia and analgesia largely depend on tumor location, surgical approach, and extension of the surgical dissection. Attention should be paid to the physio-pathological changes on cardiovascular, gastrointestinal, and immune systems induced by the tumor or by chemotherapy. At the time of surgery meticulous patient preparation needs to be carried out to optimize intraoperative monitoring and minimize the risk of complications. The cross-sectional role of anesthesia in cancer care requires effective communication between all members of the multidisciplinary team.

Hypertensive crisis in children and adolescents

Hypertensive crisis is a relatively rare condition in children. However, if not treated, it might be life-threatening and lead to irreversible damage of vital organs. Clinical presentation of patients with hypertensive crisis can vary from very mild (hypertensive urgency) to severe symptoms (hypertensive emergency) despite similarly high blood pressure (BP). Individualized assessment of patients presenting with high BP with emphasis on the evaluation of end-organ damage rather than on the specific BP number is a key in guiding physician's initial management of a hypertensive crisis. The main aim of the treatment of hypertensive crisis is the prevention or treatment of life-threatening complications of hypertension-induced organ dysfunction, including neurologic, ophthalmologic, renal, and cardiac complications. While the treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to these organs, it should not be at a too fast rate to cause hypoperfusion of vital organs by an excessively rapid reduction of BP. Thus, intravenous continuous infusions rather than intravenous boluses of antihypertensive medications should be the preferable mode of initial treatment of children with hypertensive emergency.