[Secondary non-Hodgkin's lymphomas]

Developing a secondary non Hodgkin's lymphoma (NHL) more than 12 months after treatment for first cancer, is uncommon. Secondary NHL occurs sometimes after chronic lymphatic leukemia or Hodgkin's disease. The 20 years cumulative incidence rate is 3-5% after Hodgkin's disease. Secondary NHL seems less frequent after any childhood cancer. Pertinent features of secondary NHL are a high percentage of patients with extranodal tumor sites (brain, digestive tractus), high grade histological subtype, phenotype B and advanced stage. But for identical histological type and stage, the prognosis of secondary NHL seems the same than de novo NHL ones. The incidence of secondary NHL is associated to individual parameters (age), first cancer (chronic lympho proliferative syndrome, Hodgkin's disease) and previous chemo- and/or radiotherapy. Immunodeficiency is probably the most important cofactor for the subsequent development of secondary NHL. However, secondary NHL differs from NHL of immunosuppressed patients (HIV+, posttransplant) because brain lymphoma are less frequent and immunodeficiency disorders unknown. Secondary NHL are also different of therapy-associated leukemias in the late occurrence after the first treatment and in the questionable role of cytotoxic agents given for the treatment of the first cancer.