title: Bleeding-related symptoms in colorectal cancer: a 4-year nationwide population-based study.
abstract: BACKGROUND
  Little is known about the major presenting features of patients with colorectal cancer (CRC) in a population-based setting, especially regarding bleeding-related symptoms.
  
  
  OBJECTIVE
  To determine the proportion of CRC patients presenting with bleeding-related symptoms, to compare bleeders and nonbleeders and to explore the role of anticoagulants in bleeders.
  
  
  METHODS
  This was a nationwide, population-based, retrospective study, investigating all patients diagnosed with CRC in Iceland from 2008 to 2011. Bleeding-related symptoms were defined as overt bleeding, iron deficiency anaemia or a positive faecal occult blood test. Obstructive symptoms were defined as a confirmed diagnosis of ileus or dilated intestines on imaging.
  
  
  RESULTS
  Data were available for 472/496 (95%) patients, males 51%, mean age 69 (±13) years. In all, 348 (74%) patients had bleeding-related symptoms; of these 348 patients, 61% had overt bleeding. Bleeders were less likely than nonbleeders to have metastases at diagnosis, 19% vs. 34% (P < 0.001). Overt bleeders were less likely than nonbleeders to have obstructive symptoms, 2% vs. 16% respectively (P < 0.0001). Occult bleeders were more likely to have proximal cancer (69%) than both overt (17%) and nonbleeders (44%) (P < 0.0001); however, they were less likely than nonbleeders to have metastases (22% vs. 35%, P < 0.05). Bleeders were more likely to use warfarin than nonbleeders (9% vs. 3%, P < 0.05); the use of low-dose aspirin was the same (24%).
  
  
  CONCLUSIONS
  The majority of patients with CRC present with bleeding-related symptoms. Bleeders with CRC present earlier than nonbleeders. Warfarin use may induce bleeding in some patients, resulting in an earlier diagnosis.
authors.affiliation: Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Internal Medicine, Section of Gastroenterology and Hepatology, The National University Hospital, Reykjavik, Iceland.
authors.forename: J P
authors.initials: JP
authors.lastname: Hreinsson
authors.forename: J G
authors.initials: JG
authors.lastname: Jonasson
authors.forename: E S
authors.initials: ES
authors.lastname: Bjornsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018798:Anemia, Iron-Deficiency / Q000175:diagnosis / Q000453:epidemiology*; D000925:Anticoagulants / Q000009:adverse effects; D001241:Aspirin / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D006470:Hemorrhage / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D012189:Retrospective Studies; D014859:Warfarin / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D001241:Aspirin