Treatment and outcome of metastatic parathyroid carcinoma: A systematic review and pooled analysis of published cases

A giant parathyroid carcinoma cause deformation of thorax: Case report

We present a rare case of a large parathyroid carcinoma (PC) characterized by severe hyperparathyroidism, hypercalcemia, and osteoporosis. Long-standing calcium loss resulted in thoracic and facial deformities, initially misdiagnosed as oral malignancy.

Advances in the management of parathyroid carcinoma

Parathyroid carcinoma (PCA) is a rare malignancy accounting for approximately 1% of all patients with primary hyperparathyroidism. It is characterised by excessive parathyroid hormone (PTH) production. This manuscript reviews recent advances in the management of parathyroid carcinoma, focusing on molecular insights, diagnostic modalities, surgical innovations, adjuvant therapies, and emerging targeted treatments. Recently published manuscripts (between 2022 and 2023) were obtained from Medical Literature Analysis and Retrieval System Online (Medline), Excerpta Medica (Embase), Cochrane Central Register of Controlled Trials (CENTRAL), and European Union Drug Regulating Authorities Clinical Trials (EudraCT). These were assessed for their relevance in terms of the diagnosis and management of patients with PCA. This manuscript explores the role of genetic profiling and presents case studies illustrating successful management strategies. The manuscript also discusses the ongoing challenges in the management of parathyroid carcinoma, suggesting future research directions and potential therapeutic avenues.

Risk Factors of Distant Metastatic Parathyroid Carcinoma and Insights into Therapeutic Perspectives

BACKGROUND

Distant metastatic parathyroid carcinoma (DM-PC) is a rare but often lethal entity with limited data about prognostic indicators. We sought to investigate the risk factors, patterns, and outcomes of DM-PC.

METHODS

In this observational cohort study, 126 patients who underwent surgery for PC at a tertiary referral center from 2010 to 2023 were enrolled, among whom 38 had DMs. Univariate and multivariate Cox regression analyses were used to assess the effects of prognostic factors on DM.

RESULTS

The cumulative incidence of DM was 14.1%, 33.8%, and 66.9% at 5, 10, and 20 years in the duration of disease course, respectively. DM-PC patients suffered a worse 5-year overall survival of 37.1% compared with 89.8% in the non-DM patients (p < 0.001). DM-PC patients also suffered more previous operations (p < 0.001), higher preoperative serum calcium (p<0.001) and parathyroid hormone (PTH) levels (p < 0.001), lower frequencies of R0 resection (p < 0.001), higher rates of pathological vascular invasion (p = 0.020), thyroid infiltration (p = 0.027), extraglandular extension (p = 0.001), upper aerodigestive tract (UAT) invasion (p < 0.001), and lymph node metastasis (p < 0.001). Multivariate Cox regression revealed that non-R0 resection (HR 6.144, 95% CI 2.881-13.106, p < 0.001), UAT invasion (HR 3.718, 95% CI 1.782-7.756, p < 0.001), and higher preoperative PTH levels (HR 1.001, 95% CI 1.000-1.001, p = 0.012) were independent risk factors of DM.

CONCLUSIONS

Upper aerodigestive tract invasion and higher preoperative PTH levels might be risk factors for possible metastatic involvement of PC. R0 resection and closer surveillance should be considered in such cases to minimize the risk of DM and to optimize patient care.

Sporadic Parathyroid Carcinoma Treated With Lenvatinib, Exhibiting a Novel Somatic MEN1 Mutation

Parathyroid carcinoma (PC) is extremely rare and is primarily treated surgically. Chemotherapy is an option for advanced stages, but no standard regimen exists. Emerging research suggests the efficacy of multitarget tyrosine kinase inhibitors (MTKIs) for PC, targeting vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). A 61-year-old Japanese woman presented with a neck mass, diagnosed as PC with pleural and lumbar metastases. After parathyroidectomy and radiation for lumbar metastasis, immunohistochemistry showed VEGFR overexpression, leading to targeted therapy with MTKIs. Despite no actionable mutations on cancer genomic panel test, a novel MEN1 somatic mutation (NM_130801: exon2: c.332delG: p.G111fs*8) was identified, which may affect VEGFR2 expression and tumor epigenetics. Although severe hand-foot syndrome necessitated dose reductions and treatment interruptions, sorafenib treatment managed hypercalcemia with evocalcet and denosumab. Lenvatinib, as second-line therapy, was effective against pleural metastases but caused thrombocytopenia and hematuria, leading to discontinuation and uncontrolled recurrence and metastasis progression. Our case highlights the need for further research on genomic profiling, molecular targets, and therapy response in PC.

A >50% Intraoperative Parathyroid Hormone Level Decrease Into Normal Reference Range Predicts Complete Excision of Malignancy in Patients With Parathyroid Carcinoma

INTRODUCTION

The mainstay of successful treatment for parathyroid carcinoma remains complete surgical excision. Although intraoperative parathyroid hormone (ioPTH) monitoring is a useful adjunct during parathyroidectomy for benign primary hyperparathyroidism, its utility for parathyroid carcinoma remains unclear.

METHODS

A retrospective review of 796 patients who underwent parathyroidectomy with ioPTH monitoring for primary hyperparathyroidism revealed 13 patients with parathyroid carcinoma on final pathology from two academic institutions. A systematic review yielded 5 additional parathyroid carcinoma patients. Complete excision of malignancy, or operative success (eucalcemia ≥6 mo. after parathyroidectomy); operative failure (persistent hypercalcemia <6 mo. after parathyroidectomy); and perioperative complications were evaluated. Comparison of the >50% ioPTH decrease alone to >50% ioPTH decrease into normal reference range was analyzed using Chi-squared, Kolmogorov-Smirnov, Kruskal-Wallis tests.

RESULTS

All 18 parathyroid carcinoma patients achieved a >50% ioPTH decrease, and 14 patients also had a final ioPTH level decrease into normal reference range. 93% of patients who met normal parathyroid hormone reference range had operative success, whereas only two of the four (50%) patients with parathyroid carcinoma with a >50% ioPTH decrease alone demonstrated operative success.

CONCLUSIONS

Parathyroidectomy guided by a >50% ioPTH decrease into normal reference range may better predict complete excision of malignant tissue in patients with parathyroid carcinoma compared to >50% ioPTH decrease alone. IoPTH monitoring should be used in conjunction with clinical judgment and complete en bloc resection for optimal treatment and success.

The clinicopathological features of lung metastases of parathyroid cancinoma

Parathyroid carcinoma(PC) is an extremely rare malignant tumor of the parathyroid glands. The lung is the most common target organ for PC distant metastases. In this study, twelve patients diagnosed with PC with lung metastases were enrolled in the study. Hematoxylin and Eosin(H&E) stained, immunohistochemical stained and next-generation sequencing (NGS) of a 425-gene panel were performed on tumor tissue samples. At the same time, we also evaluated its histopathologic characteristics. The results indicate that the microscopic examination of metastatic lesions reveals the same structure and characteristics as PC; the tumor was composed of relatively uniform cells organized in nests and separated by thin fibrous bands and abundant blood vessels. Immunohistochemical evaluation of Ki67, CyclinD1, PTH, SYN, CgA, and CD56 was useful in diagnosing PC with lung metastases. The most frequently genetic alterations were mutations of CDC73 and copy number variation (CNV) of MCL1, with a mutation rate of 25 %. In addition, the mutations of CDC73, ATM, TP53, ALK, ERBB2, MAP3K4, TSC1, CCND1 and CNV of CDK4, MCL1, SMARCB1 overlap between metastatic lesions and primary lesions. In conclusions, PC is a rare endocrine malignant tumor that is very difficult to diagnose preoperatively and prone to clinical recurrence or distant metastasis. Genetic mutations, presentation and histological characteristic were the basis for diagnosing PC with lung metastases.

Long-term survival in a patient with metastatic parathyroid carcinoma harboring an EGFR sensitizing mutation: a case report

Parathyroid carcinoma (PC) is a rare and aggressive endocrine malignancy with limited treatment options. Current treatments such as chemotherapy and radiotherapy have demonstrated limited efficacy. Here, we report the case of a male patient who presented with symptoms including polydipsia, polyuria, and joint pain. Further examination revealed a neck lump, hypercalcemia, and hyperparathyroidism, leading to a diagnosis of PC after en bloc surgery. Seven months later, the patient developed local recurrence and lung metastases, which were resected via left lateral neck dissection and thoracoscopic wedge resection. A 422-gene panel test revealed the presence of epidermal growth factor receptor (EGFR) p.L858R (c. T2573G) mutation, which may sensitize the EGFR-tyrosine kinase inhibitor response, and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) p.E545KV (c. G1633A) mutation. After multidisciplinary treatment discussions, the patient was treated with the multi-target tyrosine kinase inhibitor, anlotinib, resulting in survival benefits for 19 months. This case highlights the potential of targeted therapy in terms of long-term survival in patients with distant metastatic PC, as well as the importance of precision therapy guided by genome sequencing to identify potential therapeutic targets.

Refractory Hypercalcemia Secondary to Metastatic Parathyroid Carcinoma Treated With Immunotherapy

Parathyroid carcinoma (PC) is a rare endocrine malignancy and an uncommon cause of primary hyperparathyroidism. Metastatic disease confers a guarded prognosis with limited systemic treatment options available. We describe a case of a 64-year-old woman with primary hyperparathyroidism secondary to PC. Despite initial surgical resection, the patient relapsed within 6 months with widespread cerebral and skeletal metastatic disease. She developed worsening parathyroid hormone-mediated hypercalcemia that was refractory to escalating doses of cinacalcet and antiresorptive therapy. Molecular genomics identified high tumor mutation burden within the malignant tissue and single-agent nivolumab immunotherapy was administered. After one dose, there was resolution of her refractory hypercalcemia and primary hyperparathyroidism. The patient has tolerated ongoing treatment with 3 weekly cycles of nivolumab. She remains in biochemical remission as of June 2024, which is now 12 months after commencement of nivolumab.

Two cases of parathyroid carcinoma associated with multiple brown tumours

We present two rare cases of parathyroid carcinomas associated with multiple brown tumours. Plain radiographs, computed tomography, and neck ultrasonography revealed the presence of bone and parathyroid tumours. Despite the use of 99m Tc-methoxy isobutyl isonitrile (99mTc-MIBI) or 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET)/CT, it was difficult to differentiate bone metastases from brown tumours. Parathyroid carcinoma was confirmed by histopathological examination following parathyroidectomy, resulting in spontaneous bone lesion improvement. In patients with parathyroid carcinoma presenting with bone lesions suggestive of metastasis, understanding the potential for brown tumour accumulation through 99mTc-MIBI or 18F-FDG PET/CT is pivotal. With this understanding, it is possible to diagnose brown tumours with parathyroidectomy and follow up for improvement of bone lesion and avoid invasive biopsy or surgery.

Efficacy of olaparib in advanced cancers with germline or somatic mutations in BRCA1, BRCA2, CHEK2 and ATM, a Belgian Precision tumor-agnostic phase II study

BACKGROUND

The Belgian Precision initiative aims to maximize the implementation of tumor-agnostic next-generation sequencing in patients with advanced cancer and enhance access to molecularly guided treatment options. Academic tumor-agnostic basket phase II studies are part of this initiative. The current investigator-driven trial aimed to investigate the efficacy of olaparib in advanced cancers with a (likely) pathogenic mutation (germline or somatic) in a gene that plays a role in homologous recombination (HR).

PATIENTS AND METHODS

This open-label, multi-cohort, phase II study examines the efficacy of olaparib in patients with an HR gene mutation in their tumor and disease progression on standard of care. Patients with a somatic or germline mutation in the same gene define a cohort. For each cohort, a Simon minimax two-stage design was used. If a response was observed in the first 13 patients, 14 additional patients were included. Here, we report the results on four completed cohorts: patients with a BRCA1, BRCA2, CHEK2 or ATM mutation.

RESULTS

The overall objective response rate across different tumor types was 11% in the BRCA1-mutated (n = 27) and 21% in the BRCA2-mutated (n = 27) cohorts. Partial responses were seen in pancreatic cancer, gallbladder cancer, endocrine carcinoma of the pancreas and parathyroid cancer. One patient with a BRCA2 germline-mutated colon cancer has an ongoing complete response with 19+ months on treatment. Median progression-free survival in responding patients was 14+ months (5-34+ months). The clinical benefit rate was 63% in the BRCA1-mutated and 46% in the BRCA2-mutated cohorts. No clinical activity was observed in the ATM (n = 13) and CHEK2 (n = 14) cohorts.

CONCLUSION

Olaparib showed efficacy in different cancer types harboring somatic or germline mutations in the BRCA1/2 genes but not in ATM and CHEK2. Patients with any cancer type harboring BRCA1/2 mutations should have access to olaparib.

Diagnostic dilemma in a rare case of nonfunctional parathyroid carcinoma at a referral facility in Northern Tanzania

Key Clinical Message

Rare cancer originating from parathyroid parenchymal cells. Preoperative diagnosis is often difficult. Presents with normal serum levels of calcium and parathyroid hormone. Treated by en bloc resection. Benefits of adjuvant therapy are unclear.

Abstract

Parathyroid carcinoma is an uncommon endocrine tumor. Its typical presentation is that of primary hyperparathyroidism with elevated serum calcium and parathormone levels. Nonfunctioning carcinoma of the parathyroid gland with normal serum calcium levels is extremely rare. This paper describes a case of nonfunctioning parathyroid carcinoma and brief literature review thereof.

Parathyroid Carcinoma Presenting as Recurrent Primary Hyperparathyroidism and Neck Mass: A Case Report

Parathyroid carcinoma is a rare endocrine neoplasm that accounts for <1% of cases of primary hyperparathyroidism. The management of parathyroid carcinoma is a challenge due to the high rate of local recurrence of the tumour. We report the case of a middle-aged north Indian woman who presented with recurrent primary hyperparathyroidism due to parathyroid carcinoma. She presented with a recurrent palpable hard neck mass and underwent radical dissection of the neck six times. At the time of writing this report, she was referred for external beam radiotherapy to the neck. Parathyroid carcinoma is a rare malignancy with an indolent but tenacious course. Complete resection at the time of initial surgery determines the prognosis of the neoplasm. Chemotherapy and radiotherapy are usually ineffective. Hypercalcaemia needs to be aggressively managed. A multidisciplinary team is required to effectively manage parathyroid carcinoma.

Clinical presentation and outcome of patients with enteric-type adenocarcinoma of the lung: A pooled analysis of published cases

Enteric-type adenocarcinoma of the lung (lung-ETAC, former pulmonary enteric adenocarcinoma, PEAC) is a rare subtype of non-small cell lung cancer (NSCLC), which shares morphological and immunohistochemical features with lung and colorectal adenocarcinoma. Few data are available on patient prognosis, possible prognostic factors and systemic approach to metastatic disease. We performed a pooled analysis and a systematic review of published lung-ETAC, along with an additional case description. Thirty-one eligible publications were identified, providing data from 126 patients. In the 127 patients overall analyzed, median overall survival (OS) was 56.0 (range 36.7-75.3) months in early-stage patients and 14.0 (range 4.5-23.5) months in those with advanced/metastatic disease. Median disease-free survival (DFS) after radical surgery was 24 (range 22.6-35.1) months. Smoking status (HR 4.304, 95% CI: 1.261-14.693, p = 0.020) and node involvement (HR 1.853, 95% CI: 1.179-2.911, p = 0.007) were the negative independent prognostic factors at multivariate analysis. As regards systemic therapies for advanced cases, no firm conclusions were drawn about the efficacy of lung cancer-oriented chemotherapy regimens as opposed to colon cancer-oriented ones. Molecular analysis of lung-ETAC revealed a relatively high mutational rate, with alterations in several druggable molecular pathways, KRAS and NRAS (31%) were the most frequently mutated oncogenes, followed by ROS1 (15%), RET (13%), BRAF (11%), EGFR (8%) and ALK (6%). Moreover, 3 (15%) out of 20 cases showed DNA mismatch repair deficiency (dMMR). In conclusion, advanced lung-ETAC patients appeared to have a better prognosis compared to other subtypes of NSCLC. Moreover, the mutational rate and microsatellite instability found in lung-ETACs suggest that a significant proportion of these patients could benefit from target therapies and immunotherapy.