Autologous Bone Marrow Transplantation - Blog Science Connections

292 ABMT Timing in Lymphoma
induction therapies were avoided because we were trying to avoid severe
damage to the normal stem cells (49,50) prior to bone marrow harvest.
Patients who continued on L-l 7M therapy after the induction therapy did not
do as well as the patients who received ABMT in CR or PR, and only 5 of 13 are
still alive. It is not possible to evaluate separately the therapeutic effectiveness
of each component of the therapy (i.e., compare induction therapy with
HF-TBI plus cyclophosphamide and ABMT rescue) in the protocol employed.
About 40% of patients had CRs after L-17M induction, and some of those
having PRs went on to CRs after ABMT. However, it is difficult to evaluate the
completeness of remission in patients with large mediastinal or retroperitoneal
masses, and some apparent CRs may be hard to confirm and others
may be of short duration. Conversely, some PRs may in reality be shown to
be CRs after surgical restaging. Only two patients (nos. 1 and 11) in this
group had surgical restaging after ABMT. Both had large persistent
mediastinal masses after ABMT, but surgical resection of these masses
revealed only necrotic tissue, fibrosis, and no residual tumor. Both patients
remain disease free 52 and 12 months after surgery. The results for ABMT
when performed immediately after induction of a CR or PR are much better
than when ABMT is performed in relapse. We therefore feel that timing of
intensive chemotherapy followed by ABMT is of critical importance.
Marrow transplantation was well tolerated by patients who received ABMT
after the induction therapy employed in our protocol. The major side effects
are listed in Table 3. As mentioned above, patients chose whether to receive
ABMT in CR or PR (group 1) or at relapse (group 2). The patient's decision was
usually based on two factors: 1) the time involved (patients in group 1 received
intensive therapy for approximately 6 months and no maintenance chemotherapy,
whereas patients in group 2 received 2-2V£ years of treatment with
frequent hospital visits) and 2) their referring physicians' assessment of the
therapeutic benefit of ABMT compared with that of continuing chemotherapy.
Although initial results are encouraging, modification of the regimen we
used may prove necessary with more experience and follow-up. It may be
possible to develop better methods of induction and ablative treatment as
well as improved ex vivo purging methods. The results of ABMT also need to
be compared to those achieved with the best drug combination protocols
(7-13) that do not involve ABMT, and we have begun a new clinical trial to do
that, comparing ABMT with MACOP-B (12) in treating patients with poor
prognostic features.
ACKNOWLEDGMENTS
This work was supported in part by the Einard and Sue Sundin Fund for
Lymphoma Research, the United Leukemia Fund, the National Leukemia
Association, the American Cancer Society, a Clinical Oncology Career