SDHB-Associated Pheochromocytomas: What is Their Clinical Behavior?

INTRODUCTION: Germline pathogenic variants in succinate dehydrogenase subunit B (SDHB) cause paraganglioma/pheochromocytoma syndrome type 4 (PGL-4). SDHB-associated pheochromocytomas (PCC) are thought to be rare and little data exist about their clinical behavior. PATIENTS AND METHODS: Retrospective review of patients treated (1993-2023) at a tertiary cancer center for SDHB-associated PCC. Clinical and demographic variables were retrieved to characterize disease-free survival, disease progression, and overall survival. RESULTS: In total, 90 SDHB-carriers were identified, 18% had PCC (n = 16). Median age at diagnosis of was 40 (19-76) years, 50% (n = 8) of patients were male, 25% (n = 4) had distant metastasis (DM) at diagnosis, and 13% (n = 2) had synchronous PGL. No patients had bilateral disease, and 94% of patients underwent surgery as initial treatment with a curative intent in 75%. Overall, 64% of patients underwent open resection. Recurrence occurred in 77% of patients (n = 10), 75% in minimally invasive surgery (MIS) versus 77% open, p = 0.63. Bone was the most common site of DM (100%, n = 13). Metaidobenzyleguanidine (MIBG) imaging was performed in 69% of patients, 91% of which were positive. Median time from surgery until recurrence was 36 months (1-295 months). Radiation therapy was the most common adjuvant treatment (44%) followed by Iobenguane I-131 (31%) and systemic therapy (31%). Median follow-up time was 56 months (1-408 months). Overall, 33% of patients were alive, 19% of patients were disease-free, and 50% of the patients with DM had stable disease at last follow-up. CONCLUSIONS: Overall, 18% of germline SDHB mutation-carriers were diagnosed with PCC, all of which were unilateral. SDHB-associated PCC was associated with advanced and recalcitrant disease and was often MIBG positive. More studies are needed to better understand the clinical behavior of PCC in PGL-4.

Pediatric Papillary Thyroid Carcinoma: Outcomes After Surgery Without Adjuvant Radioactive Iodine.

CONTEXT: Pediatric papillary thyroid carcinoma (PTC) is usually treated with total thyroidectomy followed by radioactive iodine (RAI). Recently, RAI is being used more selectively based on surgical pathology and postoperative dynamic risk stratification (DRS). OBJECTIVE: To describe patients with pediatric PTC not initially treated with RAI and their disease outcomes. METHODS: This was an ambispective study at a tertiary cancer center of patients < 19 years diagnosed from 1/1/1990 to 12/31/2021 with stage I PTC who intentionally were not treated with RAI within a year of diagnosis. We assessed clinical characteristics, management, and disease outcomes using DRS. RESULTS: Of 490 PTC patients, we identified 93 eligible patients (median age at diagnosis 16y; 87% female), including 46 (49%) with cervical lymph node metastases. Initial management included: total thyroidectomy ± neck dissection (n=69, 75%), lobectomy ± neck dissection (n=20, 21%), or a Sistrunk procedure for ectopic PTC (n=4, 4%). After a median follow-up of 5.5 years (range 1-26), most patients (85/93; 91%) remained disease-free with no further therapy. Persistent (n=5) or recurrent (n=3) disease was found in 9% of the entire cohort. Four patients ultimately received RAI, of which only one clearly benefited, and additional surgery was performed or planned in four patients, two of whom had an excellent response at last follow-up. CONCLUSIONS: Selected pediatric PTC patients, even those with lymph node metastases, may not require therapeutic 131I and can avoid the unnecessary risks of RAI while still benefitting from the excellent long-term outcomes that are well-described for this disease.

Clinical course of atypical parathyroid neoplasm with soft tissue extension.

BACKGROUND AND OBJECTIVES: The American Joint Committee on Cancer (AJCC) TNM staging system defines atypical parathyroid neoplasia (APN) as tumor in situ (Tis) and reserves the definition of parathyroid carcinoma (PC) to parathyroid tumor with invasion into surrounding structures. Because the parathyroid gland has no true capsule, "extension" with APN versus microscopic "invasion" of surrounding soft tissue can be difficult and confusing for clinicians. We aimed to determine the clinical course of atypical parathyroid neoplasm with and without soft tissue extension and parathyroid carcinoma with only soft tissue invasion (pT1) and to report the outcomes. METHODS: Following an IRB-approved protocol, we identified all patients treated for parathyroid neoplasm or cancer at our single tertiary care cancer center from 1990 to 2021. We excluded all patients with evidence of clinical or pathologic gross invasion into surrounding structures (pT2 or higher), lymph node involvement, or metastatic disease. By definition, this excluded all cases where the distinction was clinically evident to the surgeon at the time of the operation based on finding a hard, firm, sticky, or discolored parathyroid gland. Only patients with pathologic T1 (pT1) parathyroid carcinoma or APN were included. All pathologic examinations were independently re-reviewed by a single designated expert senior endocrine pathologist. The definition of APN strictly followed the WHO definition of a clinically worrisome lesion having features including fibrous bands or increased mitotic rate, necrosis, or trabecular growth that did not meet robust criteria for frank invasion. Pathologic T1 disease was defined as invasion limited to soft tissue. Analyses were performed using R version 4.0.2 and Jamovi. RESULTS: Of all PC patients at our institution, only 71 met the strict inclusion criteria of APN or pT1. Forty-four patients had pT1 disease and 27 had APN: 12 of the APN had soft tissue extension, and 15 had no soft tissue extension. The groups were similar with regard to age at diagnosis (p = 0.328). The average follow-up duration was 84 months from initial surgical intervention. Of the 12 with APN, one patient (1/12; 8%) with soft tissue extension recurred, developed distant metastases, and subsequently died during follow up. Of the 44 patients with pT1 PC, six developed distant metastases and 13 (13/44; 30%) died during the follow-up period. One patient with APN and soft tissue extension recurred and died and no patient with APN and no soft tissue extension died. CONCLUSIONS: Patients with APN and extension into soft tissue have a clinical course similar to that of APN without soft tissue extension. APN with soft tissue extension is a different disease from pT1 disease with invasion of soft tissue. The pTis classification appears justified for APN with and without soft tissue extension.

International consensus statement on the diagnosis and management of phaeochromocytoma and paraganglioma in children and adolescents.

Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours that arise not only in adulthood but also in childhood and adolescence. Up to 70-80% of childhood PPGL are hereditary, accounting for a higher incidence of metastatic and/or multifocal PPGL in paediatric patients than in adult patients. Key differences in the tumour biology and management, together with rare disease incidence and therapeutic challenges in paediatric compared with adult patients, mandate close expert cross-disciplinary teamwork. Teams should ideally include adult and paediatric endocrinologists, oncologists, cardiologists, surgeons, geneticists, pathologists, radiologists, clinical psychologists and nuclear medicine physicians. Provision of an international Consensus Statement should improve care and outcomes for children and adolescents with these tumours.

Venous thromboembolism in adrenocortical carcinoma: a retrospective analysis.

BACKGROUND: Venous thromboembolism (VTE) is a leading cause of death in patients with cancer. Limited data exist about VTE in patients with adrenocortical carcinoma (ACC). The primary objective of this study was to identify the prevalence of VTE in a cohort of patients with ACC. Secondary objectives were to determine the impact of VTE events on overall survival (OS) and to describe the characteristics of VTE in patients with ACC. PATIENTS AND METHODS: We retrospectively reviewed data from 289 patients with ACC cared for at a major referral center from February 2010 to June 2022. RESULTS: VTE prevalence was 18.7% (54 events). Thirty patients (55.6%) had pulmonary embolism (PE); 12 patients (22.2%) had deep vein thrombosis (DVT); and 12 patients (22.2%) had both PE and DVT. VTE occurred after ACC diagnosis in 50 patients (92.6%) including 44 patients (88%) with stage 3 or 4 ACC. VTEs were CTCAE grade ≤2 in 32 cases (59.3%), grade 3 in 17 (31.5%), and grade 4 in 2 (3.7%). Thirteen patients (24%) died within 6 months after VTE diagnosis, although there was no statistically significant association between VTE and overall survival. CONCLUSION: Despite the potential to underestimate the prevalence of VTEs, we found a high frequency of VTE events in patients with ACC. A majority of VTEs occurred in the context of advanced ACC and we observed high short-term mortality. Further studies are needed to validate our findings and investigate mechanisms associated with VTE in ACC.

High-Specific-Activity 131 I-MIBG for the Treatment of Advanced Pheochromocytoma and Paraganglioma.

PATIENTS AND METHODS: The primary endpoints were objective response rate (ORR) and disease control rate (DCR). Secondary endpoints were duration of response, blood pressure control, safety, overall and progression-free survival rates, MIBG uptake, and correlations with genetic background. RESULTS: The study included 25 patients. Twenty-four patients had distant metastases, 17 (68%) had hormonally active tumors, and 13 (52%) had previously received antineoplastic treatment. In 24 evaluable patients, the ORR was 38%, including 2 patients with complete response, and the DCR was 83%; median time to response was 12.5 months (95% confidence interval, 4.6-25.1). Twelve patients had sporadic disease, among whom the ORR was 25% and DCR was 83%. Twelve patients had hereditary disease ( SDHB , VHL , RET ); among these, the ORR was 50%, and DCR was 83%. Plasma metanephrines normalized in 30% of patients and improved by greater than 50% in 46%. Sixteen patients had hormonally active tumors and hypertension; in 9 (56%) of these, blood pressure normalized, leading to discontinuation of antihypertensive therapy.The most common adverse events were grades 1-2 nausea/vomiting and transient bone marrow suppression. One patient developed premature ovarian failure. Reversible grades 3-4 myelosuppression were seen in 7 patients (28%). One patient had fatal pneumonitis. CONCLUSIONS: HSA- 131 I-MIBG is associated with a high DCR in patients with MPPGL, regardless of underlying genetic mutation.

Next-Generation Sequencing in Sporadic Medullary Thyroid Cancer Patients: Mutation Profile and Disease Aggressiveness.

Context: Next-generation sequencing (NGS) analysis of sporadic medullary thyroid carcinoma (sMTC) has led to increased detection of somatic mutations, including RET M918T, which has been considered a negative prognostic indicator. Objective: This study aimed to determine the association between clinicopathologic behavior and somatic mutation identified on clinically motivated NGS. Methods: In this retrospective cohort study, patients with sMTC who underwent NGS to identify somatic mutations for treatment planning were identified. Clinicopathologic factors, time to distant metastatic disease (DMD), disease-specific survival (DSS), and overall survival (OS) were compared between somatic mutations. Results: Somatic mutations were identified in 191 sMTC tumors, including RET M918T (53.4%), other RET codons (10.5%), RAS (18.3%), somatic RET indels (8.9%), and RET/RAS wild-type (WT) status (8.9%). The median age at diagnosis was 50 years (range, 11-83); 46.1% were female. When comparing patients with RET M918T, RET-Other, and RET WT (which included RAS and RET/RAS WT), there were no differences in sex, TNM category, systemic therapy use, time to DMD, DSS, or OS. On multivariate analysis, older age at diagnosis (HR 1.05, P < .001; HR 1.06, P< .001) and M1 stage at diagnosis (HR 3.17, P = .001; HR 2.98, P = .001) were associated with decreased DSS and OS, respectively, but mutation cohort was not. When comparing RET M918T to RET indels there was no significant difference in time to DMD, DSS, or OS between the groups. Conclusion: Somatic RET mutations do not portend compromised DSS or OS in a cohort of sMTC patients who underwent clinically motivated NGS.

Pediatric Medullary Thyroid Carcinoma: Clinical Presentations and Long-Term Outcomes in 144 Patients Over 6 Decades.

CONTEXT: Sporadic medullary thyroid carcinoma (sMTC) rarely occurs in childhood and no studies have specifically focused on this entity. OBJECTIVE: To describe the clinical presentations and long-term outcomes of a large cohort of children and young adults with sMTC compared with hereditary MTC (hMTC). METHODS: Retrospective study of 144 patients diagnosed with MTC between 1961 and 2019 at an age ≤ 21 years and evaluated at a tertiary referral center. RESULTS: In contrast to hMTC (n = 124/144, 86%), patients with sMTC (n = 20/144, 14%) are older (P < .0001), have larger tumors (P < .0001), a higher initial stage grouping (P = .001) and have more structural disease (P = .0045) and distant metastases (DM) (P = .00084) at last follow-up, but are not more likely to die from MTC (P = .42). Among 77 patients diagnosed clinically, not by family history (20/20 sMTC and 57/124 hMTC), there was no difference in the initial stage (P = .27), presence of DM at diagnosis (P = 1.0), disease status at last follow-up (P = .13), overall survival (P = .57), or disease-specific survival (P = .87). Of the 12 sMTC tumors that underwent somatic testing, 11 (91%) had an identifiable alteration: 10 RET gene alterations and 1 ALK fusion. CONCLUSION: sMTC is primarily a RET-driven disease that represents 14% of childhood-onset MTC in this cohort. Pediatric sMTC patients are older, present with clinical disease at a more advanced TNM classification, and have more persistent disease at last follow-up compared with hMTC, but these differences disappear when comparing those presenting clinically. Somatic molecular testing should be considered in sMTC patients who would benefit from systemic therapy.

Decreasing utilization for postoperative radiation therapy in locoregionally advanced medullary thyroid cancer.

BACKGROUND: Use of postoperative radiation therapy (PORT) in locoregionally advanced medullary thyroid cancer (MTC) remains controversial. The objective was to evaluate the effect of PORT on locoregional control (LRC) and overall survival (OS). METHODS: Retrospective cohort study of 346 MTC patients separated into PORT and no-PORT cohorts. Relative indications for PORT, as well as changes in patterns of treatment, were recorded. RESULTS: 49/346 (14%) received PORT. PORT was associated with worse OS; adjusted HR = 2.0 (95%CI 1.3-3.3). PORT was not associated with improved LRC, even when adjusting for advanced stage (Stage III p = 0.892; Stage IV p = 0.101). PORT and targeted therapy were not associated with improved OS compared to targeted therapy alone; adjusted HR = 1.2 (95%CI 0.3-4.1). CONCLUSIONS: Use of PORT in MTC has decreased and its indications have become more selective, coinciding with the advent of effective targeted therapies. Overall, PORT was not associated with improved LRC or OS.

Incidence and Geographical Distribution of Adrenocortical Carcinoma: Retrospective Analysis of a State Cancer Registry.

OBJECTIVE: Adrenocortical carcinoma (ACC) is a rare malignancy without established association with environmental risk factors. ACC incidence is stable based on large surgical databases while referral centers data reported increasing number of cases seen. We studied ACC incidence and distribution at a county level to find potential ACC "hot spots" that could be linked to environmental exposures. METHODS: A retrospective analysis of Texas Cancer Registry that included ACC patients diagnosed between 2000 and 2018. County-level heatmaps were created and compared with breast, prostate, and lung cancer. RESULTS: We identified 448 ACC cases during the study period. Cases were registered in 110 of the 254 counties (43.3%) in Texas, representing 92.74% of the total population. The median incidence was 23 new cases/y (range 14-33). The mean population-adjusted ACC incidence rate was 0.104 per 100 000 per year (standard deviation 0.005; 95% CI, 0.092-0.116). Seven counties (6.3%) accounted for 215 (48.0%) cases, with more than 10 cases each and median standardized incidence ratio (SIR) of 0.1 (range, 0.0-0.9). One hundred three counties (93.7%) accounted for the remaining 233 cases (52%), with fewer than 10 cases per county. The highest standardized incidence ratios were found in counties with a median population of fewer than 14 000 residents and with only one reported case. CONCLUSION: Our analysis is the first report to create ACC heatmap and could not detect any geographic clustering of ACC in Texas. The incidence of ACC remained stable and consistent with data from other large databases.

Beyond the three P's: adrenal involvement in MEN1.

Adrenal lesions (ALs) are often detected in patients with multiple endocrine neoplasia type 1 (MEN1). However, they are not well described in MEN1, making their clinical management unclear. This study examined the prevalence and outcomes of ALs found in MEN1. We performed a retrospective chart review of patients diagnosed with MEN1 from 1990 to 2021. ALs were diagnosed using abdominal or thoracic imaging and classified as being unilateral or bilateral, having single or multiple nodules, and as having diffuse enlargement or not. Measurable nodular lesions were analyzed for their size and growth over time. Patients' clinical and radiographic characteristics were collected. We identified 382 patients with MEN1, 89 (23.3%) of whom had ALs. The mean age at detection was 47 ± 11.9 years. We documented 101 measurable nodular lesions (mean size, 17.5 mm; range, 3-123 mm). Twenty-seven nodules (26.7%) were smaller than 1 cm. Watchful waiting was indicated in 79 (78.2%) patients, of whom 28 (35.4%) had growing lesions. Functional lesions were diagnosed in 6 (15.8%) of 38 that had functional work-up (diagnoses: pheochromocytoma (n = 2), adrenocorticotropic hormone-dependent hypercortisolism (n = 2), hyperandrogenism (n = 1), hyperaldosteronism (n = 1)); surgery was indicated for 5 (83.3%; n = 12 nodules), 2 of whom had bilateral, diffuse adrenal enlargement. Two patients were diagnosed with adrenocortical carcinoma and two with neoplasms of uncertain malignant potential. Radiographic or clinical progression of ALs is uncommon. Malignancy should be suspected on the basis of a lesion's growth rate and size. A baseline hormonal work-up is recommended, and no further biochemical work-up is suggested when the initial assessment shows nonfunctioning lesions.

Prevalence of pituitary hormone dysfunction following radiotherapy for sinonasal and nasopharyngeal malignancies.

BACKGROUND: There are limited studies and no surveillance protocols on pituitary dysfunction for adults who underwent anterior skull base radiation. METHODS: Cross-sectional study of 50 consecutive patients with sinonasal or nasopharyngeal cancer who underwent definitive radiotherapy. The mean radiation doses, prevalence of pituitary dysfunction, and associated factors were calculated. RESULTS: Pituitary hormone levels were abnormal in 23 (46%) patients, including 6 (12%) with symptomatic abnormalities requiring treatment. The most common hormonal abnormality was hyperprolactinemia (30%), central hypothyroidism (8%) and central hypogonadism (6%). Patients with abnormal pituitary hormone values received higher mean radiation doses to the pituitary gland (1143 cGy, P = 0.04), pituitary stalk (1129 cGy, P = 0.02), optic chiasm (1094 cGy, P = 0.01), and hypothalamus (900 cGy, P = 0.01). CONCLUSIONS: Nearly half of the patients had abnormal pituitary function, including over a tenth requiring treatment. There may be a dose-dependent association between hormonal dysfunction and radiation.

Recent Therapeutic Advances in Pituitary Carcinoma.

Pituitary carcinoma (PC) is a rare, aggressive malignancy that comprises 0.1-0.2% of all pituitary tumors. PC is defined anatomically as a pituitary tumor that metastasizes outside the primary intrasellar location as noncontiguous lesions in the central nervous system or as metastases to other organs. Similar to pituitary adenoma, PC originates from various cell types of the pituitary gland and can be functioning or nonfunctioning, with the former constituting the majority of the cases. Compression of intricate skull-based structures, excessive hormonal secretion, impaired pituitary function from therapy, and systemic metastases lead to debilitating symptoms and a poor survival outcome in most cases. PC frequently recurs despite multimodality treatments, including surgical resection, radiotherapy, and biochemical and cytotoxic treatments. There is an unmet need to better understand the pathogenesis and molecular characterization of PC to improve therapeutic strategies. As our understanding of the role of signaling pathways in the tumorigenesis of and malignant transformation of PC evolves, efforts have focused on targeted therapy. In addition, recent advances in the use of immune checkpoint inhibitors to treat various solid cancers have led to an interest in exploring the role of immunotherapy for the treatment of aggressive refractory pituitary tumors. Here, we review our current understanding of the pathogenesis, molecular characterization, and treatment of PC. Particular attention is given to emerging treatment options, including targeted therapy, immunotherapy, and peptide receptor radionuclide therapy.