Neutral risk of lung cancer in adults with celiac disease - nationwide cohort study

Background: Data on celiac disease (CD) and the risk of lung cancer are contradictory, with several studies suggesting a protective effect of CD. We investigated the future risk of lung cancer in individuals with biopsy-verified CD. Methods: In this cohort study we used biopsy reports from 28 Swedish pathology departments to identify adults with CD who had been diagnosed between 1969 and 2008 (Marsh 3: villous atrophy). Each patient with CD (n= 18,365) was matched with up to five reference individuals (n= 90,962) from the general population matched for age, sex, calendar year and county. Lung cancer events were identified through the Swedish Cancer Register. Using Cox regression, we then calculated hazard ratios (HRs) for lung cancer. Results: During follow-up there were 109 cases of lung cancer in patients with CD, and 470 among reference individuals. This corresponded to a HR of 1.07 (95% CI = 0.87-1.32). The absolute risk of future lung cancer in patients with CD was 57/100,000 person-years (excess risk = 4/100,000 person-years). In the first year after CD diagnosis, the HR for lung cancer was 2.01 (95% CI = 1.08-3.76), decreasing to a HR of 1.00 beyond the first year of follow-up (95% CI = 0.80-1.25).There was no difference in men or women with CD, and age at CD onset did not influence the risk of lung cancer. Conclusion: In a Swedish setting, patients with CD were at a similar risk of lung cancer to reference individuals from the general population.