Patients with inflammatory bowel disease (IBD) have an increased risk of developing blood cancers but the risk is only marginally higher than normal. The take-home message for patients and their doctors is that there is no real reason for worry Researchers from the Karolinska Hospital, Stockholm, assessed the occurrence of blood cancers in more than 47,000 Swedish patients with two forms of inflammatory bowel disease - Crohn's disease or ulcerative colitis. Compared to the general population, people with ulcerative colitis or Crohn's disease were both about 10 percent to 20 percent more likely to develop a blood cancer. Since such cancers are quite rare, however, this increased risk represents the occurrence of less than one extra case every 10 years among 1000 people with IBD. Patients with IBD have an increased relative risk of (blood) cancer, which in absolute terms is small. The researchers did find that a particular type of leukaemia - myeloid leukaemia - occurred at a rate 80 percent higher than expected in ulcerative colitis patients, but this again represents a very small number of cases. With respect to the link between ulcerative colitis and myeloid leukaemias, this will remain a scientifically important question but the absolute excess risk for patients is low.
Gut,
May 2005