Coeliac disease characteristics, compliance to a gluten free diet and risk of lymphoma by subtype.
OBJECTIVE
Coeliac disease is associated with an increased risk of malignant lymphomas. We investigated the importance of coeliac disease characteristics and diet compliance for risk of lymphoma.


METHODS
In a nested case-control design, we identified 59 patients with lymphoma and 137 matched controls from a population-based cohort of 11,650 inpatients with coeliac disease. We assessed coeliac disease characteristics at diagnosis and dietary compliance collected prospectively from medical records during follow-up.


RESULTS
Poor compliance was not significantly associated with risk of lymphoma overall (odds ratio 1.83, 95% confidence interval 0.78-4.31) nor of lymphoma subtypes. Risk estimates differed by subtype; risk of T-cell lymphoma (odds ratio 1.01, confidence interval 0.32-3.15) or intestinal lymphoma (odds ratio 0.66, confidence interval 0.17-2.56) was unelevated, whereas there was an indication of a risk increase of B-cell lymphoma (odds ratio 4.74, confidence interval 0.89-25.3) or extraintestinal lymphoma (odds ratio 3.00, confidence interval 0.73-12.3) following poor compliance. History of weight loss (odds ratio 2.89, confidence interval 1.00-8.29) at coeliac disease diagnosis was associated with an increased risk of lymphoma when excluding tumours occurring with short latency (<3 years).


CONCLUSIONS
Compliance to a gluten-free diet did not significantly alter lymphoma risk, but a moderate effect cannot be excluded. Weight loss, a potential marker of coeliac disease severity, may be associated with lymphoma risk.