Hemato-Oncology-4

HEMATO-ONCOLOGY PART-4

Welcome to the fourth part of a series on Hemato-oncology.
Question: Dr. Chiragbhai, last time we discussed two case examples for stem cell transplant in hematology-oncology i.e. its role in Acute Myeloid Leukemiaand Multiple Myeloma. As per NCCN and other guidelines, it is part of initial therapy for many cases i.e. even before there is relapse.
What are the other established indications?
Answer: Over 70 different diseases can be treated by use of Stem Cell Transplant, as a standard option, wherever available. We cannot discuss all these diseases here, but broadly they can be divided in three categories:

1. Malignant e.g. multiple myeloma; leukemia-AML, ALL, CML, CLL and others;
   Lymphoma-Hodgkin, Non Hodgkin; MDS-Myelodysplastic
   syndrome; Myelofibrosis; relapsed testicular cancer and others.

2. Benign e.g. Aplastic anemia; Some other severe autoimmune disorders, and others.

3. Genetic e.g. Thalassemia major, Sickle cell disease, SCID, many inborn errors of Metabolism, and others.

Most common indications world over, in terms of numbers, are Multiple myeloma (initial and relapsed), Lymphomas (relapsed, occasionally initial), Leukemias (mainly AML, ALL, CML), MDS, Aplastic anemia, Thalassemia.

Que: That is a big list. So, how does it work in so many different diseases, with different pathophysiology?
Ans: That is a very good question. There are 3 roles of transplant, using hematopoietic stem cells:

1. Provide a missing gene by replacing defective stem cells with healthy stem cells e.g. in thalassemia major or sickle cell disease, child is normal except just one missing gene.
2. As a form of Supportive Care e.g. in cancers, where we give a large dose of chemotherapy to remove resistant cancer cells or large doses of immunosuppressives in autoimmune diseases. In this process, majority of bone marrow stem cells are also killed, which are regenerated by stem cells.
3. Immunological effects e.g. in some cancers there is a GVL-graft v leukemia effect, which provides additional help in clearing cancer cells.

So, even though the procedure is almost similar, transplant works through at least three different mechanisms in these diseases.

Next time, we will talk about role in Benign and Genetic Disorders.

Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 98243 12144, 98988 31496
Diplomate American Board of Oncology and Hematology. Ahmedabad. drchiragashah@gmail.com
Shyam Hem-Onc Clinic. 402 Galaxy, Near Nehrunagar Circle, Ahmedabad.