PHILADELPHIA -- Patients with inflammatory bowel disease (IBD) who had a recent colonoscopy were less likely to develop colorectal cancer and were less likely to die from the disease after a colon cancer diagnosis, researchers said here.
Among almost 7,000 patients with IBD, the incidence of colorectal cancer was 2.7% for those who had not had a colonoscopy compared with 1.6% of those who had the screening test within the 3-year follow-up (P=0.001), for an unadjusted odds ratio of 0.56 (95% CI 0.39-0.80), according to , of Massachusetts General Hospital in Boston, and colleagues.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
In addition, for IBD patients diagnosed with colorectal cancer, mortality was "much lower," at 14% among those who had recently undergone colonoscopy compared with 34% for those who had not (P=0.012), for an OR of 0.34 (95% CI 0.12-0.95), he said during a plenary session at the annual meeting of the American College of Gastroenterology.
"Colorectal cancer is one of the most common cancers affecting both women and men. In 2013, there were nearly 150,000 new cases diagnosed and 50,000 deaths," Ananthakrishnan said.
"Patients with IBD are at increased risk for colorectal cancer and current professional societies recommend surveillance colonoscopies beginning 8 years after the diagnosis of IBD at 2- to 3-year intervals," he said.
In the general population, colonoscopy has been shown to decrease the mortality associated with colorectal cancer, but this has not previously been shown for patients with IBD.
To explore this, he and his colleagues analyzed outcomes from a large IBD cohort, including patients who had been followed at their centers for at least 3 years.
Their analysis included 6,823 patients with ulcerative colitis or Crohn's disease, 2,764 of whom had undergone a colonoscopy within the previous 3 years.
Among those who did not have a recent colonoscopy, the diagnosis more often was ulcerative colitis, while among those with a recent colonoscopy, there was more use of immunomodulator and biologic therapies.
After adjustment for age, sex, type of IBD, disease duration, and co-existing primary sclerosing cholangitis, the significant difference between risk for colorectal cancer persisted, with an OR of 0.65 (95% CI 0.45-0.93), Ananthakrishnan reported.
Moreover, the odds ratios remained essential unchanged on sensitivity analyses that adjusted for healthcare utilization, inflammatory burden, and immunosuppressive therapies.
In a virtual press conference, , director of endoscopy at Brigham and Women's Hospital in Boston, said, "I believe this is the first time we've had the formal link of cancer and mortality in the IBD population. IBD is a major risk factor for colorectal cancer and it does have a different pathogenesis or pathway than in patients without IBD."
"Local inflammation in the colon likely predisposes these patients to the malignancy," Ananthakrishnan told 51˶.
Limitations of the study included its taking place at tertiary care centers and the lack of information on the quality of colonoscopies or how many biopsies were done.
Nonetheless, "these findings support continued surveillance for colorectal cancer among patients with IBD," Ananthakrishnan concluded.
Disclosures
Ananthakrishnan and co-authors disclosed no relevant relationships with industry.
Primary Source
American College of Gastroenterology
Source Reference: Ananthakrishnan A, et al "Colonoscopy is associated with a reduced risk of colon cancer and mortality in patients with inflammatory bowel disease" ACG 2014; Abstract 9.