title: Increasing Incidence of Colorectal Cancer, Starting at a Younger Age for Rectal Compared to Colon Cancer in Brunei Darussalam.
abstract: BACKGROUND
  Colorectal cancer (CRC) is the most common gastrointestinal malignancy and is a significant cause of mortality. Its incidence is generally increasing in Asia. Reports from the West have indicated that the incidence of rectal cancer is increasing in the younger population. This study assessed the time trend of CRC in Brunei Darussalam specifically assessing the different age groups at which the incidences start to increase.
  
  
  METHODS
  The National Cancer registry was reviewed (1991 to 2014). The age standardized rate (ASR) and the age specific incidence rates (ASIRs) for three time periods (1991-1998), (1999-2006) and (2007-2014) were calculated.
  
  
  RESULTS
  The mean age of diagnosis was 59.3±14.6 years old, incidences being slightly higher amongst men (57.6%) and Malays (67.1%). The most common tumor type was adenocarcinoma (96.4%). Rectal cancers accounted for 35.2% (n=372/1,056) of all cancers of the large bowel; more men were affected than women. The proportion of rectal cancer was also high among the indigenous group. In the three time periods, the ASR for CRC increased from 16 per 100,000 (1991-1998) to 19.6 per 100,000 (1999-2006) and 24.3 per 100,000 (2007-2014). The ASIRs for CRC increased markedly between the time periods 1998-2006 and 2007-2014, beginning in the 40-44 years age group. For rectal cancers, the ASIRs started to increase in the 25-29 age group onward whereas for colon cancers, the increase was observed at a later age, starting from the 45-49 age group.
  
  
  CONCLUSIONS
  Our study showed an increase in the incidence of CRC including in the younger age groups. The increase was seen earlier in rectal cancer compared to colon cancer. These data mirror the trends reported from the West.
authors.affiliation: Department of Medicine, Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital, Bandar Seri Begawan, Brunei Darussalam E-mail : chongvuih@yahoo.co.uk.
authors.forename: Vui Heng
authors.initials: VH
authors.lastname: Chong
authors.forename: Pemasari Upali
authors.initials: PU
authors.lastname: Telisinghe
authors.forename: Ian
authors.initials: I
authors.lastname: Bickle
authors.forename: Muhamad Syafiq
authors.initials: MS
authors.lastname: Abdullah
authors.forename: Ediwn
authors.initials: E
authors.lastname: Lim
authors.forename: Chee Fui
authors.initials: CF
authors.lastname: Chong
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002010:Brunei / Q000453:epidemiology; D018279:Carcinoma, Signet Ring Cell / Q000453:epidemiology* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003110:Colonic Neoplasms / Q000453:epidemiology* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008223:Lymphoma / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000453:epidemiology* / Q000473:pathology; D011379:Prognosis; D012004:Rectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D055815:Young Adult