title: Rectal versus non-rectal primary signet ring cell carcinoma of the colorectum: a retrospective survival analysis controlled for confounders.
abstract: OBJECTIVE
  Our objective was to compare the outcomes of rectal and non-rectal primary signet ring cell adenocarcinoma of the colorectum.
  
  
  METHODS
  A retrospective survival analysis was performed using the Surveillance, Epidemiology, and End Results Program database between 2004 and 2009 on subjects who were diagnosed as having a primary signet ring cell carcinoma of the colorectum. Cox proportional hazard regression analysis controlled for confounders was used to assess overall survival comparing rectal and non-rectal cancers.
  
  
  RESULTS
  Our population was composed of 1,484 patients: 200 affected by rectal cancer and 1,284 by non-rectal cancer. Unadjusted survival curves resulted to be almost superimposable (P = 0.916). After controlling for age, gender, race, tumor stage, grade, and size, tumor location demonstrated a statistically significant impact on overall survival (P = 0.032; 95% confidence interval 0.640-0.980; hazard ratio 0.792).
  
  
  CONCLUSIONS
  On the basis of analysis of information from the SEER database, the signet ring cell carcinoma of the rectum was associated to a worse prognosis as compared to non-rectal cancer.
authors.affiliation: General and Emergency Surgery, Department of Surgery, University of L'Aquila, Ospedale San Salvatore, 67100, L'Aquila, Italy, ciarro85@hotmail.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ciarrocchi
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000401:mortality; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000706:statistics & numerical data; D018279:Carcinoma, Signet Ring Cell / Q000401:mortality* / Q000601:surgery / Q000628:therapy; D003110:Colonic Neoplasms / Q000401:mortality* / Q000601:surgery / Q000628:therapy; D015986:Confounding Factors, Epidemiologic; D013505:Digestive System Surgical Procedures / Q000706:statistics & numerical data; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality* / Q000601:surgery / Q000628:therapy; D012189:Retrospective Studies; D018426:SEER Program / Q000706:statistics & numerical data; D047368:Tumor Burden; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American