People with Crohn’s disease, an inflammatory bowel disease (IBD), are more likely to experience a post-surgery disease relapse if they smoke, new research finds.
The study, “Mercaptopurine versus placebo to prevent recurrence of Crohn’s disease after surgical resection (TOPPIC): a multicentre, double-blind, randomised controlled trial,” was published in the August issue of the journal The Lancet.
“There is an unmet need to identify therapies or life-style changes that prevent Crohn’s disease recurrence after surgery to avoid patients having to undergo multiple operations,” Jack Satsangi, the study’s leader and a professor at the Centre of Genomics and Experimental Medicine at the University of Edinburgh, said in a press release. “Our study confirms that the most important thing somebody with Crohn’s disease can do for their health is not to smoke.”
Researchers assessed if mercaptopurine — a medication from the thiopurine family, a class of drugs that dampen the immune system, and a class commonly prescribed to Crohn’s patients — was effective at preventing relapses after surgery. (In Crohn’s disease, the immune system attacks the lining of the gut and bowel, causing severe inflammation. More than half of all patients eventually require surgery to remove the affected section of the bowel. But even after surgery, the condition can flare again.)
The study involved 240 Crohn’s disease patients from across the U.K. Participants were monitored for three years after undergoing surgery. In total, 128 patients were given mercaptopurine, and 122 were given placebo.
Of the 29 smokers, only three in the mercaptopurine group experienced a relapse, compared to 12 of the 26 smokers who received placebo. The relapse rate in the non-smoking group was much lower, and no notable added benefit was reported by giving patients mercaptopurine.
“Treatment with mercaptopurine to delay or prevent postoperative recurrence was particularly effective in people who continue to smoke; thus, in smokers, thiopurine treatment seems to be justified in the early postoperative period,” the researchers wrote.
Researchers now suggest that the therapy be offered immediately after surgery to patients who are unable to quit smoking.
“People who are unable to quit smoking are at high risk of relapse after surgery and may begin treatment with thiopurines immediately after their operation,” said Satsangi. “For non-smokers, however, we found that thiopurines offer little benefit at preventing relapse after surgery. For these patients, close monitoring in the first year is the best course of action, rather than immediate drug therapy.”
Scotland suffers from a particularly high prevalence of Crohn’s disease, and its incidence in children has risen significantly in recent years, the study noted.