VI Autologous Bone Marrow Transplantation.pdf - Blog Science ...

HODGKIN'S DISEASE: AUTOLOGOUS BMT FOLLOWING RELAPSE
AFTER PRIMARY CHEMOTHERAPY
G.L. Phillips, MD
Leukemia/Bone Marrow Transplantation Program of British Columbia:
Division of Hematology, Vancouver General Hospital, British Columbia
Cancer Agency and the University of British Columbia,
Vancouver, British Columbia, Canada.
INTRODUCTION
Myeloablative therapy and autologous bone marrow transplant (AuBMT)
regimens are widely used for patients with Hodgkin's disease.l However, the
optimal time in the course of a patient's disease to employ such therapy is unclear.
2
While this uncertainty is chiefly due to a lack of randomized trials, 3
this
statement is simplistic, as it is arguable whether AuBMT regimens have been
developed to the extent that such trials would be appropriate to test this question.
4
Alternatively, a meta-analysis that addresses this issue has been reported; 5
while of interest, the meta-analysis is based on a series of assumptions and is
therefore sensitive to the accuracy of those assumptions.
In any case, we believe that the optimal time to employ AuBMT is at the
first sign of failure of optimal primary chemotherapy - either failure to achieve
an initial complete remission ("primary induction failure") or first relapse - before
any salvage chemotherapy has been given. (Since there is no reasonable alternative
to the use of AuBMT for primary induction failure patients, this situation
will not be discussed further herein.)
More controversy exists regarding subsequent treatment in those patients
who achieve a documented complete remission before relapsing. Conventional
salvage chemotherapy has a degree of efficacy6 which, although limited, may
produce very satisfactory results in patients with an initial lymphoma-free interval
of > 12 months. 7
Moreover, it is at least possible that the apparently superior
results of AuBMT regimens are due to patient selection 4
; if so, it is possible that
AuBMT should be reserved until after conventional salvage chemotherapy fails.
Alternatively, conventional salvage therapy could be used to produce a state of
"minimal residual disease" ("sensitive relapse") before the use of AuBMT.
However, if one accepts that use of AuBMT regimens at some point after relapse
is optimal, utilization of AuBMT at the time of first relapse is an attractive
option as it exposes relatively few patients who could be cured by safer, more
conventional therapies to the intrinsic risks of AuBMT regimens 7
; its use only in
patients whose lymphoma-free interval is < 12 months emphasizes this strategy,
which permits treatment of a relatively healthy patient who is neither heavily
pretreated (with associated severe organ dysfunction) nor has an extensive
population of highly resistant tumor stem cells. However, we admit that this position
is controversial^ and rather than contrive various comparisons of pub-
86 SIXTH INTERNATIONAL SYMPOSIUM ON AUTOLOGOUS BONE MARROW TRANSPLANTATION