Clinical course and prognostic factors in patients with malignant pheochromocytoma and paraganglioma: A single institution experience.

OBJECTIVES: Malignant pheochromocytoma (PCC)/paraganglioma (PG) are rare neuroendocrine malignancies, and their clinical courses and prognoses are not well understood. This study aimed to evaluate prognostic factors associated with the survival of malignant PCC/PG. METHODS: This retrospective study reviewed 299 patients with PCC and 46 with PG treated between 1997 and 2013 at our single tertiary hospital. Malignant PCC/PG was defined as the presence of distant metastasis or recurrence at sites where neuroendocrine tissue is normally not present. RESULTS: Twenty-seven patients (9%) were confirmed with malignant PCC and six patients (13%) with malignant PG. Twenty-seven patients (82%) had distant metastases, nine patients (27%) presented with a metastasis at the initial diagnosis, whilst 24 patients (73%) were diagnosed with malignant PCC/PG during follow-up (median, 4.3 year). The median survival was 7.2 years, and the 5 year survival rate was 75.4%. Older age (>45 years), larger tumor size (>6 cm), synchronous metastasis, and absence of surgical excision were associated with poor survival by univariate analysis. By multivariate analysis, older age (HR = 4.3, P = 0.02) and synchronous metastasis (HR = 4.3, P = 0.01) were significantly associated with a poor prognosis. CONCLUSIONS: Patients with malignant PCC/PG have diverse clinical courses. Poor survival was independently associated with older age and synchronous metastasis.