Professor Logan and colleagues evaluated colorectal cancer risk in taking 5-aminosalicylates for inflammatory bowel disease (IBD).
The research team used the General Practice Research Database, which contains the primary care records of 5 million people in the UK.
The team utilized the database to identify users of mesalazine, balsalazide, olsalazine, or sulfasalazine with a history of IBD.
In a nested case control analysis, colorectal cancer cases with any use of a 5-aminosalicylates 6 months before the diagnosis was assessed.
The researchers matched the cases by age, sex, and calendar time to 6 control patients who were also currently using 5-aminosalicylates.
Patients were then classified according to regularity of use.
The analysis was controlled for body mass index, IBD duration, and history of colorectal polyps.
|The adjusted odds ratio for colorectal cancer with 13 to 30 prescriptions of sulfasalazine was 0.4|
The researchers also controlled for use of non-steroidal anti-inflammatory drugs, paracetamol, aspirin, and immunosuppressants.
Oral and rectal glucocorticoids, prior gastrointestinal hospitalisation, and recorded colonoscopy were also controlled in the analysis.
In addition, the team assessed for the number of visits to the general practitioner for IBD symptoms in the 6 to 24 months before diagnosis.
The study population included 18,969 patients, of whom 100 had developed colorectal cancer during 5-aminosalicylates exposure.
The team noted that most of these cases had a history of ulcerative colitis.
In the case control analysis, regular users were defined as having 6 or more 5-aminosalicylates prescriptions in the previous 12 months.
The researchers found that regular users had a decreased risk of colorectal cancer compared with irregular users.
Regular users of sulfasalazine with 6 to 12 prescriptions before had an adjusted odds ratio of 0.95.
With 13 to 30 prior prescriptions, the odds ratio for regular users of sulfasalazine was 0.40, and with more than 30 prior prescriptions this was 0.77.
The team observed that for mesalazine users, the values for the number of prescriptions were 1.13, 0.30, and 0.31, respectively.
Professor Logan's team concluded, “These results show that regular 5-aminosalicylates use is associated with some reduction in the risk of colorectal cancer developing in ulcerative colitis.”