LWBK1006-42 LWW-Govindan-Review December 12, 2011 20:38
Chapter 42•Stem Cell Transplantation 531ANSWERS
Answer 42.1. The answer is D.
High-dose chemotherapy (and/or radiation) conditioning regimens have
significant antitumor activity and are typically used in younger patients
with aggressive hematologic malignancies. Historically, it was believed
that the curative potential of allogeneic HCT was derived entirely from the
conditioning regimen, and that the donor graft served only as hematopoi-
etic “rescue.” It is now known that the graft can mediate a powerful
immunologic “GVL effect” that can contribute significantly to the cura-
tive potential of the transplant. GVHD represents the deleterious reverse
of GVL, an immunologic attack on normal tissue.Answer 42.2. The answer is D.
The primary objectives of allogeneic transplant conditioning are to pro-
vide sufficient immunosuppression of the host immune system to permit
donor engraftment, and particularly with fully myeloablative regimens, to
achieve significant cytoreduction of tumor cells by incorporating agents
with known activity against the underlying malignancy. The conditioning
regimen, administered before infusion of donor cells, does not exert a
significant impact on the risk of GVHD.Answer 42.3. The answer is D.
High-dose cyclophosphamide in combination with 1200 to 1350 cGy
TBI or busulfan 13.8 mg/m^2 IV constitute the two most commonly used
myeloablative conditioning regimens for allogeneic transplantation. Flu-
darabine and ATG, although significantly lymphosuppressive, have min-
imal myelosuppressive effects.Answer 42.4. The answer is C.
Two randomized clinical trials have failed to demonstrate differences in
disease-free survival among patients with CML conditioned with either
cyclophosphamide and busulfan or cyclophosphamide and TBI. Although
the use of reduced-intensity conditioning regimens (answer D) has shown
promise in older patients with CML, there are insufficient data comparing
such approaches with traditional myeloablative regimens to recommend
their routine use in younger patients who are candidates for myeloablative
conditioning.Answer 42.5. The answer is C.
Although acute cardiac toxicity, characterized by cardiomyopathy,
arrhythmia, or pericarditis, may be seen with cytarabine and mitox-
antrone, this toxicity is most commonly caused by cyclophosphamide.
Busulfan is not commonly associated with cardiac toxicity but may cause
VOD and pneumonitis.