Very late relapses in patients with Burkitt's lymphoma: clinical and serologic studies.

Of 117 patients in remission for at least 12 months after chemotherapy for confirmed Burkitt's lymphoma, 14 subsequently relapsed. Frequency of ever relapsing in this group varied from 12% 2 years after chemotherapy to 3-8% 3-6 years after chemotherapy. Risk of very late relapse (VLR) increased with the occurrence of meningeal disease and/or relapse before a remission of 12 months or more was achieved. The use of combination chemotherapy and especially prophylactic intrathecal methotrexate significantly lowered the risk of VLR (P less than 0.03). Serial testing for antibodies to Epstein-Barr viral capsid antigen to the diffuse and restricted components of the early antigen complex and to the Epstein-Barr virus-specific nuclear antigen revealed minor fluctuations but no consistent increases in antibody titers preceding detection of VLR. The serologic follow-up tests thus were not clinically useful for prediction of the imminence of a recurrence. Patients developing VLR generally maintained moderate-to-high titers of antibodies to restricted or diffuse components throughout the long remission periods, which indicated that they were not beyond the danger of a relapse at an unspecified time in the future.