Malignancies and mortality in patients with coeliac disease and dermatitis herpetiformis: 30-year population-based study.

BACKGROUND AND AIM: To assess the long-term risks of malignant diseases and mortality in patients with coeliac disease and dermatitis herpetiformis in a centre, where the prevalence of these diseases is high. The risks have probably been overestimated, as patients with subtle forms have earlier remained undetected. PATIENTS: The study comprised 17,245 person-years of follow-up in 1147 patients. METHODS: The observed numbers of malignancies and causes of deaths were assessed, and compared to those expected, and standardised incidence ratio and standardised mortality ratio given. RESULTS: The occurrence of all malignant conditions was equal to that in the population both in coeliac disease and dermatitis herpetiformis: standardised incidence ratios of 1.2 (95% confidence intervals 0.9-1.5) and 1.0 (0.6-1.5), respectively. Five patients with coeliac disease and seven with dermatitis herpetiformis had developed non-Hodgkin lymphoma; standardised incidence ratios of 3.2 (1.0-7.5) and 6.0 (2.4-12.4), respectively. Four patients with coeliac disease and one with dermatitis herpetiformis had enteropathy-associated T-cell lymphoma, associated with inadequate dietary compliance. Mortality was increased (standardised mortality ratio 1.26; 1.00-1.55) in coeliac disease, but decreased in dermatitis herpetiformis (standardised mortality ratio 0.52; 0.36-0.72). CONCLUSION: The overall prognosis in our patients was good. Non-Hodgkin lymphoma emerged in patients with undiagnosed or poorly treated coeliac disease. The mortality rate in dermatitis herpetiformis was even lower than in the population. Our data support the early diagnosis and dietary treatment of these conditions.