| Forces International | ULCERATIVE COLITIS IS ASSOCIATED WITH NON-SMOKING |
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| Forces International | ULCERATIVE COLITIS IS ASSOCIATED WITH NON-SMOKING |
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| Anti-smokers try to link an inflammatory bowel disease, Crohn's disease, with smoking.
But in a dual meta-analysis of Crohn's Disease (CD) and ulcerative colitis (UC), former
smokers had no less risk for CD than current smokers, while their risk increased greatly
for UC. Antibiotics such as Metronidazole have been effective in treating CD (but not UC).
Also, areas with high rates of UC often have high rates of CD as well. This suggests that
the association of smoking with CD is not causal. Anti-smokers have claimed that smokers require more operations, without noting that their high operation rate in the first years after diagnosis more likely reflects the doctors' own preference for surgical over medical management, for which they unfairly blame smokers. Also, after 30 years the probability of surgery in this disease is nearly 90% anyhow. By contrast, about 90% of the victims of ulcerative colitis are non-smokers. They are at 3.5 times greater risk than smokers. In ex-smokers, onset is nearly always after quitting smoking. Smoking appears to have a protective effect against the development of this disease, and also reduces its severity. This is important because the earlier it occurs, and the more extensive it is, the greater is the risk of future colorectal cancer. By 35 years after diagnosis, the absolute risk of colorectal cancer is 30% to 40%. The actual number of cancer cases is lower, however, because of the large number of proctocolectomies and rectal amputations which are compelled by bowel inflammation and hemorrhaging. In a cohort of 213 with disease of more than 8 years' duration, for example, there were 6 deaths from carcinoma of the colon and 54 colectomies during 13 years' follow-up. These were the relatively mild cases. The severe cases must have colectomies within 8 years. Colorectal cancer risk in UC about equal in men and women. But women and men with UC have respectively a 9.5 and 45.5 times greater risk of liver and gallbladder cancer, and 31 times the risk of primary sclerosing cholangitis, which are not influenced by medical or surgical treatment of UC. Overall cancer risk is 1.8 times that of the general population, which is more than the alleged excess risk to smokers. In 1970, US incidence was about equal in males and females. In males, the peak incidences were at ages 20-29 and 70-79, and in females, at 30-39 and 70-79. Most new cases are among younger people due to their greater numbers. Annual age adjusted incidence rates are about 6 per 100,000, which would extrapolate to 15,000 new cases per year. About 9390 would be excess cases due to non-smoking, or about 63%. With more non-smokers, it must nowadays be more than this. UC rates are five times higher among non-smoking Mormons than in the general population, so there could potentially be 60,000 to 75,000 new cases per year, if the anti-smokers had their way. (And, CD rates were not lower among the Mormons.) In fact, a recent review of 56 studies from 1930 to 1990 has shown that, while the ratio of male to female cases has remained the same in children, with a slight male preponderance, in adults UC has changed from mainly female to a male preponderance also. This has been seen in Denmark, Iceland and Sweden as well. In Japan, where few women smoke, UC is still mainly a female disease. In Olmsted County, MN, the prevalence of ulcerative colitis is about 225 per 100,000. This would equate to 562,000 cases in the US. The cost of colon cancer screening by biopsy, a reasonable preventive measure in these high-risk patients, is estimated at $570 per year. The average cancer treatment cost is $24,000, while proctocolectomy and ileoanal anastomosis averages $25,000. With about 2% needing colectomy for severe UC and 0.2% requiring cancer treatment per year, these annual costs would be $621.5 million. With 63% attributable to non-smoking, the excess cost could be up to $391.5 million. Since over half of all cases appear before age 40, most of the cost would be carried by employee health insurance. This does not include hospitalizations without colectomy, liver transplants, or lost productivity. The cause of ulcerative colitis is unknown. There is no consistently effective treatment for it. Steroids reduce inflammation, but side effects prevent them from being used for long. But many individual patients have found relief by smoking, and a controlled trial of nicotine gum helped three of five patients. Chewing tobacco could probably also be used. It is no coincidence that ulcerative colitis help groups are becoming common. But for political reasons, people are not told that this is a risk of non-smoking. UC patients could represent just the tip of an iceberg of increased risk for colorectal and/or liver and gallbladder cancer. Tobacco could give people with ulcerative colitis many years of disease-free living, or even save their lives.
Courtesy of Carol Thompson
08/23/93 |
Calkins BM. A
meta-analysis of the role of smoking in inflammatory bowel disease. Dig Dis Sci 1989
Dec;34(12):1841-1854.