title: Clinical course and prognostic factors in patients with malignant pheochromocytoma and paraganglioma: A single institution experience.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yun Mi
authors.initials: YM
authors.lastname: Choi
authors.affiliation: Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Tae-Yon
authors.initials: TY
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Won Gu
authors.initials: WG
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Ryu
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Kim
authors.affiliation: Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Suck Joon
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dong Eun
authors.initials: DE
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
mesh_terms: D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D000315:Adrenalectomy; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000401:mortality* / Q000556:secondary* / Q000628:therapy; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
keywords: distant metastasis; neoplasms; paraganglioma; pheochromocytoma