title: Primary colorectal signet-ring cell carcinoma: clinicopathological features and postoperative survival.
abstract: OBJECTIVE
  The objective of this study was to investigate the clinicopathological features and postoperative survival of primary colorectal signet-ring cell carcinoma.
  
  
  METHODS
  Nineteen patients with primary colorectal signet-ring cell carcinoma were identified from a database of 5884 surgical patients with colorectal cancers treated surgically at Osaka University Hospital and affiliated hospitals between 1993 and 2007. The clinicopathological data of those patients were compared with those of 5792 patients with non-signet-ring cell colorectal carcinoma (5417 with well or moderately differentiated adenocarcinoma and 375 with poorly differentiated adenocarcinoma or mucinous carcinoma).
  
  
  RESULTS
  All patients showed a tumor depth of over T3. Lymph node involvement occurred in 14 patients. Seven of 19 patients presented with distant metastasis at the time of diagnosis. The overall 5-year survival rate in primary signet-ring cell carcinoma was significantly lower at 24.1%, in comparison to 77.5% in well or moderately differentiated adenocarcinoma and 57.7% in poorly differentiated adenocarcinoma or mucinous carcinoma. Likewise, the postoperative survival in Stage III was also significantly worse. On the other hand, no significant difference was observed in Stage II or IV.
  
  
  CONCLUSIONS
  The most important feature of primary colorectal signet-ring cell carcinoma is the advanced stage at the time of diagnosis. In addition, the postoperative survival is worse than for other types of colorectal cancer.
authors.affiliation: Department of Surgery, Rinku General Medical Center, Izumisano Municipal Hospital, Izumisano, Osaka, Japan.
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Mizushima
authors.forename: Masaya
authors.initials: M
authors.lastname: Nomura
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujii
authors.forename: Hiroki
authors.initials: H
authors.lastname: Akamatsu
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mizuno
authors.forename: Harumi
authors.initials: H
authors.lastname: Tominaga
authors.forename: Junichi
authors.initials: J
authors.lastname: Hasegawa
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Nakajima
authors.forename: Keigo
authors.initials: K
authors.lastname: Yasumasa
authors.forename: Masato
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Toshirou
authors.initials: T
authors.lastname: Nishida
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016019:Survival Analysis