Myeloablation using chemotherapeutic agents is useful in cancer treatment because:
A. It destroys the myelocytes (muscle cells).
B. It reduces the size of the cancer tumor.
C. After surgery, it reduces the amount of chemotherapy needed.
D. It destroys the bone marrow prior to transplant.
Correct Answer: D. It destroys the bone marrow prior to transplant.
Myelo comes from the Greek word myelos, which means marrow. Ablation comes from the Latin word ablatio, which means removal. Thus, myeloablative chemotherapeutic agents destroy the bone marrow. This procedure destroys normal bone marrow as well as the cancerous marrow. The patient’s bone marrow will be replaced with a bone marrow transplant. Myelocytes are not muscle cells. Tumors are solid masses typically located in organs. Surgery may be performed to reduce tumor burden and require less chemotherapy afterward.
Option A: A combination of agents expected to produce profound pancytopenia and myeloablation within 1–3 weeks from administration; pancytopenia is long-lasting, usually irreversible, and in most instances fatal unless hematopoiesis is restored by hematopoietic stem cell infusion.
Option B: MA regimens usually produce rapid engraftment of donor cells, which may be followed . in a proportion of patients, by graft versus host disease (GvHD). MA regimens are associated with toxicity and mortality –referred to as transplant-related mortality (TRM)- depending on variables such as patient age, donor age, donor/recipient HLA matching, gender matching, phase of the underlying disease (early or advanced), and year of transplant.
Option C: The anti-leukemia effect of MA regimens can be further enhanced with the use of targeted radio-immunoconjugates (28), which would in theory not increase regimen-related toxicity. However since the use of these agents in the context of conditioning regimens remains investigational, their exact place in the intensity spectrum is unknown.