title: Colorectal cancer incidence and survival by sub-site and stage of diagnosis: a population-based study at the advent of national screening.
abstract: BACKGROUND
  The location and staging of a colorectal cancer (CRC) determine prognosis and choice of treatment. We examined the sub-site, sex, and stage distribution for CRC in Ireland for patients diagnosed in the period immediately prior to the implementation of a national screening programme.
  
  
  METHODS
  Incident cases of CRC were abstracted from the National Cancer Registry for the period 1994-2012 (n = 38,912). Incidence proportions and 3-year cancer-related survival were calculated.
  
  
  RESULTS
  The incidence of CRC during 2010-2012 averaged 1021 females and 1424 males per year. While the overall incidence rate of CRC was static during 1994-2012, this masked a significant increase in the rate of proximal colon tumours (+1.3 % per year), a decreases in the rate of tumours of overlapping/colon NOS (-2.2 % per year), and no change in the rates of cancers of the distal colon and rectosigmoid junction (RSJ)/rectum. Proximal tumours occurred more frequently in females (F vs. M, 38 vs. 29 %), in older persons and increased over time. Compared to distal colon tumours, proximal colon [RR risk ratio 1.08, 95 % CI (1.05, 1.10)] and RSJ/rectum tumours [RR 1.08 (1.05, 1.11)] were more likely to be diagnosed at late stage. The proportion of late-stage tumours increased steadily over five diagnosis periods [e.g., 1994-1997 (51 %) vs. 2010-2012 (57 %), RR 1.12 (1.08, 1.16)]. Cancer survival improved over four diagnosis periods.
  
  
  CONCLUSIONS
  There was a distal-to-proximal shift and a trend towards diagnosis at late stage during 1994-2012. Some reversal of this trend is expected following the implementation of a national screening programme.
authors.affiliation: National Cancer Registry, 6800 Avenue 6000, Cork Airport Business Park, Cork, T12 CDF7, Ireland. j.mcdevitt@ncri.ie.
authors.forename: J
authors.initials: J
authors.lastname: McDevitt
authors.affiliation: National Cancer Registry, 6800 Avenue 6000, Cork Airport Business Park, Cork, T12 CDF7, Ireland.
authors.forename: H
authors.initials: H
authors.lastname: Comber
authors.affiliation: National Cancer Registry, 6800 Avenue 6000, Cork Airport Business Park, Cork, T12 CDF7, Ireland.
authors.forename: P M
authors.initials: PM
authors.lastname: Walsh
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D007494:Ireland; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology*; D012042:Registries
keywords: Colon; Colorectal cancer; Rectum; Stage