Prevalence of anaemia at diagnosis of colorectal cancer: assessment of associated risk factors.

BACKGROUND/AIMS: The aim of this study was to report the prevalence of anaemia in patients with cancer located in different anatomical segments of the colon and rectum and to assess possible risk factors for this anaemia.

METHODOLOGY: The study included 1189 patients referred during 1980-2004 with a colorectal adenocarcinoma. Data were obtained from hospital records and from the Norwegian Cancer Registry. Risk factors for anaemia were analyzed in multivariable logistic regression analysis. The WHO definition of anaemia was used.

RESULTS

The prevalence of anaemia diminished gradually and linearly as the location of the tumours was more distal towards the rectum. Anaemia was found in 74.7% (215/288) of the patients with cancer in the coecum or ascending colon, 57.1% (48/84) in the transverse colon, 40.0% (180/300) in the sigmoid and 30.5% (114/374) in the rectum. In the multivariable analysis, age, location of the tumour and T-stage remained associated with anaemia, whereas the histological differentiation of the tumour, N-stage, M-stage, period of admission, duration of symptoms and rectal bleeding were not.

CONCLUSIONS

Anaemia was common, especially in patients with proximal colon cancer. T-stage but not N-stage or M-stage was associated with anaemia.