Genotype-Phenotype Correlations and Clinical Outcomes in 155 Cases of Pheochromocytoma and Paraganglioma

Metastatic pheochromocytoma and paraganglioma: Integrating tumor biology in clinical practice

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors derived from chromaffin cells in the autonomic nervous system. Depending on their location, these tumors are capable of excessive catecholamine production, which may lead to uncontrolled hypertension and other life-threatening complications. They are associated with a significant risk of metastatic disease and are often caused by an inherited germline mutation. Although surgery can cure localized disease and lead to remission, treatments for metastatic PPGL (mPPGL)-including chemotherapy, radiopharmaceutical agents, multikinase inhibitors, and immunotherapy used alone or in combination- aim to control tumor growth and limit organ damage. Substantial advances have been made in understanding hereditary and somatic molecular signaling pathways that play a role in tumor growth and metastasis. Treatment options for metastatic disease are rapidly evolving, and this paper aims to provide a brief overview of the management of mPPGL with a focus on therapy options.

Metastatic disease and major adverse cardiovascular events preceding diagnosis are the main determinants of disease-specific survival of pheochromocytoma/paraganglioma: long-term follow-up of 303 patients

Purpose

The natural history in unselected cohorts of patients with pheochromocytoma/ paraganglioma (PPGL) followed for a period >10 years remains limited. We aimed to describe baseline characteristics and outcome of a large cohort and to identify predictors of shorter survival.

Methods

This retrospective single-center study included 303 patients with newly diagnosed PPGL from 1968 to December 31, 2023, in 199 prospectively supplemented since July 2020. Mean follow-up was 11.4 (range 0.3-50) years, germline genetic analyses were available in 92.1%. The main outcome measures were overall (OAS), disease-specific (DSS), recurrence-free (RFS) survival and predictors of shorter survival evaluated in patients with metastases at first diagnosis (n=12), metastatic (n=24) and nonmetastatic (n=33) recurrences and without evidence of PPGL after first surgery (n=234).

Results

Age at study begin was 49.4 ± 16.3 years. There were 72 (23.8%) deaths, 15 (5.0%), 29 (9.6%) and 28 (9.2%) due to PPGL, cardiovascular disease (CVD) and malignant or other diseases, respectively. Median OAS, DSS1 (tumor-related) and DSS2 (DSS1 and death caused by CVD) were 4.8, 5.9 and 5.2 years (patients with metastases at first diagnosis), 21.2, 21.2 and 19.9 years, and 38.0, undefined and 38.0 years (patients with metastatic and with nonmetastatic recurrences, respectively). Major adverse cardiovascular events (MACE) preceded the first diagnosis in 15% (n=44). Shorter DSS2 correlated with older age (P ≤ 0.001), male sex (P ≤ 0.02), MACE (P ≤ 0.01) and primary metastases (P<0.0001, also for DSS1).

Conclusion

The clinical course of unselected patients with PPGL is rather benign. Survival rates remain high for decades, unless there are MACE before diagnosis or metastatic disease.

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.