Autologous Bone Marrow Transplantation - Blog Science Connections

Summary 743
hybridization techniques. The lack of proper means of evaluation in patients
again underlined the need for realistic animal models of residual disease,
such as the brown Norway rat myelocytic leukemia model.
LYMPHOMAS
The second large session of the meeting was devoted to the use of ABMT
in the treatment of non-Hodgkin's lymphoma (NHL). This session reflected
one of the statements recently made by the organizers, "The exact role of
high-dose chemotherapy in salvaging relapsing or resistant patients, as well
as its role in intensification therapy for patients who have a high risk of relapse,
is difficult to define. One of the main reasons for this difficulty is that the
treatment of lymphoma is everchanging" (10). Therefore, patient selection
and prognostic indicators were main topics for the discussions.
Buckner presented results of more than 100 resistant patients with NHL
who were treated with ablative cytoreduction and BMT. The overall diseasefree
survival rate was approximately 20%. Interestingly, these results were not
different from those in patients treated with syngeneic or allogeneic bone
marrow grafts. This would suggest that therapeutic failures are mainly due to
inadequate tumor eradication in the host. The Seattle group, in an attempt to
improve these results, has recently replaced the conditioning of cyclophosphamide
and TBI with a regimen of high-dose cytarabine and TBI, but this has
not produced better results.
Philip (from Lyons) announced one of the most important developments,
which was an international randomized study in relapsed adult intermediate
and high-grade NHL. This trial is to be initiated in January 1987. The
autologous bone marrow arm of the study uses involved-field irradiation and
intensive chemotherapy (BEAC regimen: carmustine, etoposide, cytarabine,
and cyclophosphamide). This study will enroll 300 patients and has diseasefree
survival as its end point. The importance of such trials cannot be
overestimated, because proper animal models for the study of therapeutic
regimens for malignant lymphomas are not available. Other speakers described
their pioneering work on the application of ABMT in patients with
Burkitt's lymphoma and multiple myeloma, which involved purging of the
bone marrow graft. In the case of multiple myelomas, there may be a place for
allogeneic BMT. When ABMT is used, it might be profitable to concentrate on
the use of purified stem cells instead of on the selective elimination of
myeloma cells.
SOLID TUMORS
The treatment of neuroblastomas was dealt with in a separate session.
Because of the special characteristics of neuroblastoma cells, this disease
offers good prospects for successful purging of the marrow. Because of the