Identification of Predictors of Metastatic Potential in Paragangliomas to Develop a Prognostic Score (PSPGL)

Context

Paragangliomas (PGLs) are rare tumors in adrenal and extra-adrenal locations. Metastasis are found in approximately 5% to 35% of PGLs, and there are no reliable predictors of metastatic disease.

Objective

This work aimed to develop a prognostic score of metastatic potential in PGLs.

Methods

A retrospective analysis was conducted of clinical data from a cohort with PGLs and tumor histological assessment. Patients were divided into metastatic PGL (presence of metastasis) and nonmetastatic PGL (absence of metastasis ≥96 months of follow-up) groups. Univariate and multivariable analysis were performed to identify predictors of metastatic potential. A prognostic score was developed based on coefficients of multivariable analysis. Kaplan-Meier curves were generated to estimate disease-specific survival (DSS).

Results

Out of 263 patients, 35 patients had metastatic PGL and 110 patients had nonmetastatic PGL. In multivariable analysis, 4 features were independently related to metastatic disease and composed the Prognostic Score of Paragangliomas (PSPGL): presence of central or confluent necrosis (33 points), more than 3 mitosis/10 high-power field (HPF) (28 points), extension into adipose tissue (20 points), and extra-adrenal location (19 points). A PSPGL of 24 or greater showed similar sensitivity with higher specificity than the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP). PSPGL less than or equal to 20 was associated with a risk of metastasis of approximately 10%, whereas a PSPGL of 40 or greater was associated with approximately 80%. The presence of metastasis and Ki-67 of 3% or greater were related to lower DSS.

Conclusion

The PSPGL, composed of 4 easy-to-assess parameters, demonstrated good performance in predicting metastatic potential and good ability in estimating metastasis risk.

Novel GLCCI1-BRAF fusion drives kinase signaling in a case of pheochromocytomatosis

INTRODUCTION

Recurrent and metastatic pheochromocytoma (PCC) are rare advanced endocrine neoplasms with limited treatment options. Insight into the pathogenic molecular alterations in patients with advanced PCC can provide therapeutic options for precisely targeting dysregulated pathways.

OBJECTIVE

We report the discovery and characterization of a novel BRAF-containing fusion transcript and its downstream molecular alterations in a patient with recurrent PCC with peritoneal seeding (pheochromocytomatosis).

METHODS

We reviewed the medical record of a patient with pheochromocytomatosis. A comprehensive pan-cancer molecular profiling using next-generation sequencing (NGS) as well as confirmatory real-time-quantitative PCR were performed on surgical specimens. BRAF rearrangement and downstream molecular changes were assayed using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Western blot was used to assess the in vitro activation of the mitogen-activated protein kinase (MAPK) signaling pathway and the EMT markers in transfected HEK-293 cells.

RESULTS

The NGS analysis of a specimen from a 72-year-old female patient with pheochromocytomatosis showed an in-frame fusion of exon 3 of Glucocorticoid Induced 1 (GLCCI1) to exon 9 of BRAF. The upstream auto-inhibitory domain of BRAF was excluded from the GLCCI1-BRAF fusion; however, the downstream BRAF kinase domain was intact. A BRAF rearrangement was confirmed via a BRAF-specific break-apart FISH assay. Four separate tumor foci harbored GLCCI1-BRAF fusion. IHC demonstrated increased phosphorylated MEK. HEK-293 cells transfected with the GLCCI1-BRAF fusion demonstrated increased phosphorylated MEK as well as higher expression of EMT markers SNAI1 and ZEB1 in vitro.

CONCLUSION

We demonstrate a novel pathogenic gene fusion of GLCCI1 with the oncogenic kinase domain of BRAF, resulting in an activation of the MAPK signaling pathway and EMT markers. Thus, this patient may benefit from clinically available MEK and/or BRAF inhibitors when systemic therapy is indicated.

SUMMARY STATEMENT

This report is the first of GLCCI1 fused to BRAF in a human neoplasm and only the second BRAF-containing fusion transcript in PCC. Detailed molecular characterization of PCC can be a valuable tool in managing patients with recurrent PCC and pheochromocytomatosis that represents a significant clinical challenge.

Epidemiology and Prognosis of Pheochromocytoma/Paraganglioma in Korea: A Nationwide Study Based on the National Health Insurance Service

BACKGROUND

Pheochromocytomas and paragangliomas (PPGLs) are rare endocrine tumors originating from chromaffin cells. PPGLs are associated with a high mortality rate and several complications. To date, no epidemiological studies have been conducted on PPGLs in Asia. This study aimed to investigate the epidemiology and prognosis of PPGLs in Korea using nationwide data.

METHODS

Using the National Health Insurance Service Database, subjects with a principal diagnosis of PPGLs on two or more occasions between 2003 and 2014 who satisfied the operational definition of PPGLs were included. Incidence, prevalence, complications, metastasis, and mortality were investigated.

RESULTS

In total, 1048 subjects with a mean age of 47.6±16.1 years were included. There was no sex preponderance. The overall prevalence of PPGLs was 2.13 per 100,000 persons, and the overall age-standardized incidence rate was 0.18 per 100,000 person-years. Malignant PPGLs accounted for 17.7% (185 of 1,048) of cases, and 94 subjects exhibited metastasis at the time of diagnosis. Among initially non-metastatic PPGLs, 9.5% (nine of 954) eventually metastasized after a mean duration of 78.1±41.4 months. The 5-year survival rates for non-metastatic and metastatic PPGLs at diagnosis were 97% and 84%, respectively. Multivariable Cox regression models adjusted for covariates showed that metastatic PPGLs were associated with a 2.40-fold higher risk of mortality than non-metastatic PPGLs (95% confidence interval, 1.38 to 4.17; P=0.002).

CONCLUSION

PPGLs are rare in Korea, and the prognosis of these endocrine tumors varies depending on whether they are benign or malignant. This epidemiological study paves the way for further research on PPGLs.

[Pheochromocytomatosis after adrenalectomy: metastasis or cell seeding?]

Pheochromocytomatosis is defined as a multifocal cell dissemination limited to the operatively opened space with no signs of distant metastasis. After primary adrenalectomy due to a pheochromocytoma this is a rare and underrecognized manifestation of a tumor recurrence. Between 2010 and 2019 a total of 5 patients with the presentation of pheochromocytomatosis were treated in this center. Clinical and survival data were compared to 12 patients with a metastasized pheochromocytoma. Patients presenting with pheochromocytomatosis showed a better but not significant overall survival (136.8 vs. 107 months). Furthermore, patients with pheochromocytomatosis presented more often with a noradrenaline secretion type. Tumor recurrence in the pheochromocytomatosis group occurred on average 69.2 months after the initial diagnosis and was therefore much later than in patients with distant metastases from a pheochromocytoma (39 months, p = 0.13). This article outlines this special manifestation of recurrence of a pheochromocytoma based on this patient collective. Besides technical operative aspects there appears to be evidence for tumor-specific factors that promote the development of pheochromocytomatosis. Importantly, it seems that all patients with a pheochromocytoma should receive lifelong aftercare and that patients should be closely monitored during the first 5 years after surgery.

Pheochromocytomatosis associated with a novel TMEM127 mutation

Pheochromocytomatosis, a very rare form of pheochromocytoma recurrence, refers to new, multiple, and often small pheochromocytomas growing in and around the surgical resection bed of a previous adrenalectomy for a solitary pheochromocytoma. We here report a case of pheochromocytomatosis in a 70-year-old female. At age 64 years, she was diagnosed with a 6-cm right pheochromocytoma. She underwent laparoscopic right adrenalectomy, during which the tumor capsule was ruptured. At age 67 years, CT of abdomen did not detect recurrence. At age 69 years, she began experiencing episodes of headache and diaphoresis. At age 70 years, biochemical markers of pheochromocytoma became elevated with normal calcitonin level. CT revealed multiple nodules of various sizes in the right adrenal fossa, some of which were positive on metaiodobenzylguanidine (MIBG) scan. She underwent open resection of pheochromocytomatosis. Histological examination confirmed numerous pheochromocytomas ranging 0.1–1.2 cm in size. Next-generation sequencing of a panel of genes found a novel heterozygous germline c.570delC mutation in TMEM127, one of the genes that, if mutated, confers susceptibility to syndromic pheochromocytoma. Molecular analysis showed that the c.570delC mutation is likely pathogenic. Our case highlights the typical presentation of pheochromocytomatosis, a rare complication of adrenalectomy for pheochromocytoma. Previous cases and ours collectively demonstrate that tumor capsule rupture during adrenalectomy is a risk factor for pheochromocytomatosis. We also report a novel TMEM127 mutation in this case.