title: Esophageal cancer associated with other primary cancers--historical comparison of clinicopathologic features in 359 esophageal cancer patients.
abstract: OBJECTIVE
  We historically investigated the clinicopathologic features of esophageal cancer associated with other primary cancers (OPC), and discussed differences between the last decade and the previous period.
  
  
  METHODS
  A total of 359 patients with esophageal cancer treated between 1981 and 2006 were enrolled. They were divided into 2 groups; 213 patients between 1981 and 1996 (Group-A), and 146 patients between 1997 and 2006 (Group-B).
  
  
  RESULTS
  Between Group-A and Group-B, there was a significant difference in the frequency of OPC (15.5% vs. 32.2%, p < 0.001). Regarding the site of OPC, there was a significant difference in the frequency of head and neck cancers (p < 0.001). There was a significant difference in the frequency of metachronous OPC between Group-A and Group-B (5.6% vs. 18.5%, p < 0.001). Antecedent OPC was more frequently observed in Group-B than Group-A (3.3% vs. 11.0%, p < 0.01), and subsequent OPC was also more frequently observed in Group-B than Group-A (2.8% vs. 7.5%, p < 0.05). Although the 5-year survival rate after esophagectomy of the patients without OPC was better in Group-B than Group-A (31.5 % vs. 52.7 %; p < 0.01), there was no difference in that of the patients with OPC between Group-A and Group-B, (40.7% vs. 54.2%).
  
  
  CONCLUSIONS
  Metachronous as well as synchronous OPC in esophageal cancer patients were more frequent in the recent period than in the previous period. We should consider antecedent, synchronous, and subsequent OPC in esophageal cancer patients.
authors.affiliation: Department of Surgery, Shinshu University School of Medicine, Asahi, 3-1-1, Matsumoto, 390-8621, Japan. nkoide@shinshu-u.ac.jp
authors.forename: Naohiko
authors.initials: N
authors.lastname: Koide
authors.forename: Daisuke
authors.initials: D
authors.lastname: Komatsu
authors.forename: Risako
authors.initials: R
authors.lastname: Hiraga
authors.forename: Masato
authors.initials: M
authors.lastname: Kitazawa
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyagawa
mesh_terms: D004938:Esophageal Neoplasms / Q000401:mortality / Q000473:pathology*; D006801:Humans; D009378:Neoplasms, Multiple Primary / Q000401:mortality / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000401:mortality / Q000473:pathology*; D015996:Survival Rate