title: Changes of Clinicopathologic Characteristics and Survival Outcomes of Anaplastic and Poorly Differentiated Thyroid Carcinoma.
abstract: This study aimed to analyze the temporal changes of the clinicopathologic characteristics, and the long-term outcomes, of various types of anaplastic thyroid cancer (ATC) and poorly differentiated thyroid cancer (PDTC).
  
  
  
  A retrospective analysis was conducted on patients with ATC and PDTC who were treated from 1985 to 2013. The outcome measures included the clinical response to treatment and the survival rates of three separate thyroid cancer groups: ATC, PDTC, and differentiated thyroid cancer (DTC) with anaplastic foci.
  
  
  
  The five-year disease-specific survival rate was significantly higher, both in DTC with anaplastic foci and in PTDC (81.3% and 65.8%, respectively), than it was in ATC (14.3%; p < 0.001). The proportion of cases of DTC with anaplastic foci has been increasing over time, while that of ATC has decreased. The survival rate was found to be significantly higher in resectable tumors (71.4% and 26.5%, respectively; p < 0 .001). In ATC, external beam radiation therapy showed longer survival rates than did surgery-based treatment in unresectable tumors (19.2 vs. 7.7 months, p = 0.006). Adjuvant treatment with external beam radiation or radioactive iodine increased survival duration in PDTC and in DTC with anaplastic foci. Lymphatic invasion was the most significant postoperative prognosticator in ATC (p = 0.013).
  
  
  
  The choice of treatment of ATC and PDTC could be modified according to resectability and lymphatic invasion of the cancer.
authors.affiliation: 1 Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine , Seoul, Korea.
authors.forename: Doh Young
authors.initials: DY
authors.lastname: Lee
authors.affiliation: 2 Department of Pathology, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Jae-Kyung
authors.initials: JK
authors.lastname: Won
authors.affiliation: 3 Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, Korea.
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: 4 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Do Joon
authors.initials: DJ
authors.lastname: Park
authors.affiliation: 2 Department of Pathology, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Kyeong Cheon
authors.initials: KC
authors.lastname: Jung
authors.affiliation: 5 Department of Otorhinolaryngology-Head and Neck Surgery and Cancer Research Institute, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Myung-Whun
authors.initials: MW
authors.lastname: Sung
authors.affiliation: 6 Department of Radiation Oncology, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Hong-Gyun
authors.initials: HG
authors.lastname: Wu
authors.affiliation: 5 Department of Otorhinolaryngology-Head and Neck Surgery and Cancer Research Institute, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: 4 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Park
authors.affiliation: 5 Department of Otorhinolaryngology-Head and Neck Surgery and Cancer Research Institute, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: J Hun
authors.initials: JH
authors.lastname: Hah
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D002454:Cell Differentiation; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D015994:Incidence; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D042601:Lymphatic Vessels / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use*; D018714:Radiotherapy, Adjuvant; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D065646:Thyroid Carcinoma, Anaplastic / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D013965:Thyroidectomy / Q000009:adverse effects / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals