title: Colorectal cancer in U.S. adults younger than 50 years of age, 1998-2001.
abstract: BACKGROUND
  Colorectal cancer (CRC) incidence rates are increasing among persons younger than 50 years of age, a population routinely not screened unless an individual has a high risk of CRC. This population-based study focuses primarily on describing the CRC burden for persons in this age group.
  
  
  METHODS
  The data used for this study were derived from the National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) surveillance systems. Age-adjusted incidence rates, rate ratios, and their corresponding 95% confidence intervals were calculated.
  
  
  RESULTS
  CRC is ranked among the top 10 cancers occurring in males and females aged 20-49 years regardless of race. Persons younger than 50 years were more likely to present with less localized and more distant disease than do older adults. Among younger adults, age-adjusted incidence rates for poorly differentiated cancers were twice as high as rates for well-differentiated cancers. Incidence rates for poorly differentiated cancers were 60% higher than that for well-differentiated cancers diagnosed in older adults. Rates were significantly higher for blacks and significantly lower for Asians/Pacific Islanders when compared with that for whites for the most demographic and tumor characteristics examined.
  
  
  CONCLUSIONS
  This study confirms the findings of previous population-based studies suggesting that younger patients present with more advanced disease than do older patients. This study also identifies racial and ethnic disparities in CRC incidence in this population. These findings suggest the need for additional studies to understand the behavior and etiology of CRC in blacks.
authors.affiliation: Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. tfairley@cdc.gov
authors.forename: Temeika L
authors.initials: TL
authors.lastname: Fairley
authors.forename: Cheryll J
authors.initials: CJ
authors.lastname: Cardinez
authors.forename: Jim
authors.initials: J
authors.lastname: Martin
authors.forename: Linda
authors.initials: L
authors.lastname: Alley
authors.forename: Carol
authors.initials: C
authors.lastname: Friedman
authors.forename: Brenda
authors.initials: B
authors.lastname: Edwards
authors.forename: Patricia
authors.initials: P
authors.lastname: Jamison
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D005006:Ethnicity; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012042:Registries; D014481:United States / Q000453:epidemiology