Development of cancer in patients with primary immunodeficiencies.

Primary immunodeficiencies (PIDs) are genetic disorders that predispose to frequent and severe infections, autoimmunity and cancer. The expanded life span of such patients increases the overall risk for developing cancer, which is now estimated at 4-25%. The type of malignancy depends on the primary immunodeficiency, the age of the patient and possible viral infection, suggesting that different pathogenetic mechanisms are implicated in each case. Non-Hodgkin's lymphomas predominate, accounting for 60% of cases. The PIDs known to be associated with increased incidence of malignancy are: common variable immunodeficiency, IgA deficiency and DNA repair disorders. During recent years other types have also been included, such as severe combined immunodeficiency (SCID) and Wiskott Aldrich syndrome (WAS).