title: Adenocarcinoma of the rectum in patients under age 40 is increasing: impact of signet-ring cell histology.
abstract: BACKGROUND
  Overall, the incidence of colorectal cancer appears to be stable or diminishing. However, based on our practice pattern, we observed that the incidence of rectal cancer in patients under 40 is increasing and may be associated with a prominence of signet-ring cell histology.
  
  
  OBJECTIVE
  The aim of this study was to verify the rising trend in rectal cancer in patients under 40 and describe the histology prominent in that cohort.
  
  
  METHODS
  This is a retrospective cohort study.
  
  
  METHODS
  We performed a retrospective cohort study of all patients diagnosed with rectal adenocarcinoma from 1980 to 2010 using the Surveillance, Epidemiology, and End Results cancer registry.
  
  
  METHODS
  Rectal cancer incidence, histology, and associated staging characteristics were the primary outcomes measured.
  
  
  RESULTS
  Although the incidence of rectal cancer for all ages remained stable from 1980 to 2010, we observed an annual percent change of +3.6% in the incidence of rectal cancer in patients under 40. The prevalence of signet cell histology in patients under 40 was significantly greater than in patients over 40 (3% vs 0.87%, p < 0.01). A multivariate regression analysis revealed an adjusted odds ratio of 3.6 (95% CI, 2.6-5.1) for signet cell histology in rectal adenocarcinoma under age 40. Signet cell histology was also significantly associated with a more advanced stage at presentation, poorly differentiated tumor grade, and worse prognosis compared with mucinous and nonmucinous rectal adenocarcinoma.
  
  
  CONCLUSIONS
  The study was limited by its retrospective nature and the information available in the Surveillance, Epidemiology, and End Results database.
  
  
  CONCLUSIONS
  Despite a stable incidence of rectal cancer for all ages, the incidence in patients under 40 has quadrupled since 1980, and cancers in this group are 3.6 times more likely to have signet cell histology. Given the worse outcomes associated with signet cell histology, these data highlight a need for thorough evaluation of young patients with rectal symptoms.
authors: 1 Division of Colon and Rectal Surgery, University of Minnesota, Minneapolis, Minnesota 2 Division of Colon and Rectal Surgery, University of Cincinnati, Cincinnati, Ohio 3 Center for Colorectal Disease, St Vincent's University Hospital, Dublin, Ireland 4 Division of Colon and Rectal Surgery, University of Illinois, Chicago, Illinois.
authors: Patrick S
authors: PS
authors: Tawadros
authors: Ian M
authors: IM
authors: Paquette
authors: Ann M
authors: AM
authors: Hanly
authors: Anders F
authors: AF
authors: Mellgren
authors: David A
authors: DA
authors: Rothenberger
authors: Robert D
authors: RD
authors: Madoff
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000453:epidemiology* / Q000473:pathology; D000328:Adult; D017677:Age Distribution; D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000453:epidemiology* / Q000473:pathology; D015331:Cohort Studies; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D018426:SEER Program; D013223:Statistics as Topic; D014481:United States / Q000453:epidemiology; D055815:Young Adult