Medical history and risk for lymphoma: results of a population-based case-control study in Germany.

Since lymphomas are malignancies of cells of the immune system, associations with disorders characterised by impaired immune functions can be assumed. We investigated the relationship between a history of selected medical conditions and the risk for lymphoma including specified subentities within our population-based case-control study of lymphoma among adults conducted in Germany between 1999 and 2002. Overall, we found decreased risks for a history of repeated diarrhoea, warts, arthrosis, allergies, and appendectomy (at a younger age). Elevated risks for lymphoma correlated with tonsillectomy (at a younger age), whereas null results were found for selected auto-immune disorders in adulthood. Although the numbers are small, most of the results for the subentities corresponded with these findings. These results are compatible with the notion that persistent immunological alterations contribute to the aetiology of lymphoma, but partially inconsistent with the Th1/Th2-shift paradigm.