Objectives: The association between celiac disease and malignancies is well recognized. In Finland, the prevalence of clinically diagnosed adult celiac disease is 0.6%. In this large, population-based cohort, we aimed at a realistic projection of the cancer risk.
Methods: In the period 2002-2011, the register comprised 32,439 adult celiac patients. This was linked with the Finnish Cancer Registry, which covers over 98% of diagnosed malignancies. The standardized incidence ratio (SIR) was calculated for the malignancies, on the basis of incidence figures for the whole population. A time-stratified analysis was made in celiac patients diagnosed after 2004 (n=11,991). Lifestyle factors, including smoking habits and obesity, were not obtainable.
Results: The overall incidence ratio of malignant diseases was not increased (SIR 0.94; 95% confidence intervals 0.89-0.98), but it was ≥5 years from the diagnosis of celiac disease (1.31, 1.04-1.63). The SIRs for non-Hodgkin lymphoma (NHL; 1.94; 1.62-2.29), small-intestinal cancer (4.29; 2.83-6.24), colon cancer (1.35; 1.13-1.58), and basal cell carcinoma of the skin (1.13; 1.03-1.22) were increased, whereas those for lung cancer (0.60; 0.48-0.74), pancreatic cancer (0.73; 0.53-0.97), bladder cancer (0.53; 0.35-0.77), renal cancer (0.72; 0.51-0.99), and breast cancer (0.70; 0.62-0.79) were decreased. SIR for NHL immediately after the diagnosis of celiac disease was 2.56 (1.37-4.38).
Conclusions: There was no increased SIR of cancer in the whole series, but SIR was increased after 5 years from the diagnosis of celiac disease. The risk of breast and lung cancers was decreased. The risk of small-intestinal cancer and NHL was increased, but to a lesser extent than previously described.