title: Central nervous system relapse in unfavourable-histology non-Hodgkin's lymphoma: is prophylaxis indicated?
abstract: In 2 randomised, prospective Eastern Co-operative Oncology Group trials, the frequency of central nervous system (CNS) involvement after chemotherapy in 347 adults with stage III and IV unfavourable-histology, non-Hodgkin's lymphoma was 8.4%. The frequency varied from 0% in diffuse mixed lymphoma to greater than 30% in lymphoblastic and diffuse-undifferentiated lymphoma. Of the 42% of patients who achieved complete remission after chemotherapy, CNS involvement developed in 5.4% during relapse, but in only 2.7% was the CNS the sole site of relapse. CNS lymphoma arose in 6.6% of 197 patients with diffuse histiocytic lymphoma, but in only 1 subject (1%) was the CNS the sole site of relapse. Therefore, CNS prophylaxis is not indicated for the common diffuse-histology subtypes of adult non-Hodgkin's lymphoma including diffuse-histiocytic, diffuse-mixed and diffuse poorly differentiated lymphocytic lymphoma. The relatively high frequency of CNS lymphoma in lymphoblastic and diffuse undifferentiated lymphoma justify further studies of CNS prophylaxis.
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002493:Central Nervous System Diseases / Q000517:prevention & control*; D002986:Clinical Trials as Topic; D005500:Follow-Up Studies; D006801:Humans; D008223:Lymphoma / Q000188:drug therapy / Q000473:pathology*; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D011446:Prospective Studies; D011897:Random Allocation