Patients with high-stage (stage III or IV) lymphoblastic lymphoma have long-term survival rates higher than 80%. Unlike other pediatric non-Hodgkin lymphoma (NHL), it has been shown that lymphoblastic lymphoma responds much better to leukemia therapy with 2 years of therapy than with shorter, intensive, pulsed chemotherapy regimens.[1,2,3]
Involvement of the bone marrow may lead to confusion as to whether the patient has lymphoma or leukemia. Traditionally, patients with more than 25% marrow blasts are classified as having leukemia, and those with fewer than 25% marrow blasts are classified as having lymphoma. It is not yet clear whether these arbitrary definitions are biologically distinct or relevant for treatment design. All current therapies for advanced-stage lymphoblastic lymphoma have been derived from regimens designed for the treatment of acute lymphoblastic leukemia (ALL).
Lymphoma is cancer that begins in infection-fighting cells of the immune system, called lymphocytes. These cells are in the lymph nodes, spleen, thymus, bone marrow, and other parts of the body. When you have lymphoma, lymphocytes change and grow out of control.
There are two main types of lymphoma:
Non-Hodgkin: Most people with lymphoma have this type.
Non-Hodgkin and Hodgkin lymphoma each affect a different kind of lymphocyte. Every type of lymphoma grows at a different rate...
Mediastinal radiation is not necessary for patients with mediastinal masses, except in the emergency treatment of symptomatic superior vena caval obstruction or airway obstruction, where either corticosteroid therapy or low-dose radiation is usually employed. (Refer to the Treatment Option Overview section of this summary for more information on such complications.) Because of the complexities of optimal therapeutic regimens and the possibility of toxic side effects, patients should be offered the opportunity to enter into a clinical trial. Information about ongoing clinical trials is available from the NCI Web site.
The best results to date come from the Berlin-Frankfurt-Munster (BFM) group. In the GER-GPOH-NHL-BFM-90 study, the 5-year disease-free survival was 90%, and there was no difference in outcome between stage III and stage IV patients. Precursor B-cell lymphoblastic lymphoma appears to have similar results using the same therapy. In the GER-GPOH-NHL-BFM-95 study, the prophylactic cranial radiation was omitted, and the intensity of induction therapy was decreased slightly. There were no significant increases in central nervous system (CNS) relapses, suggesting cranial radiation may be reserved for patients with CNS disease at diagnosis. Of interest, the probability of 5-year event-free survival (EFS) rates was worse in NHL-BFM-95 than in NHL-BFM-90 (82% vs. 90%, respectively). Although this difference was not statistically different, NHL-BFM-95 had a reduction of asparaginase and doxorubicin in induction, which may have affected outcome. It was proposed that the major difference in EFS between NHL-BFM-90 and NHL-BFM-95 resulted from the increased number of secondary malignancies observed in NHL-BFM-95. A single-center study suggests that patients treated for lymphoblastic lymphoma have a higher incidence of secondary malignancy than do patients treated for other pediatric NHL; however, studies from the Children's Oncology Group and the Childhood Cancer Survivor Study Group do not support this finding.[5,6,7]