Due to high technologies and some innovativeness of stem cell-based treatment for certain diseases, both the medical community and patients often have questions about the safety of cell therapy.
Concerns about the harmlessness of stem cell treatment is also caused by sporadic reports in media about cases of malignancy in individuals after cell therapy.
That is why within the last decade hundreds of studies and remote monitoring of patients who underwent stem cell transplantation were conducted worldwide.
Thus, the analysis of the current scientific literature on side effects of stem cell therapy and, above all, their possible tumorigenicity (ability to cause tumors) leads to the following conclusions:
1. Transplantation of hematopoietic stem cells from bone marrow, peripheral and cord blood itself has no tumorigenic effect, and cases of malignant tumors in patients, who underwent bone marrow transplantation, are attributed to the side effects of intensive chemotherapy and / or radiation therapy, to which leukemia patients are exposed before transplantation. Indeed, the carcinogenic effect of radiation and toxic chemicals has long been known, and these factors are applied in the eradication of malignant clone in hematological malignancies and in modes of mieloablation that precedes hematopoietic stem cell transplantation in the treatment of blood cancer.
2. There is no identified risk of malignant disorders in application of non-manipulated (native) adult stem cells, which are cells of bone marrow, cord and peripheral blood, placenta, adipose tissue, etc., used in regenerative or immunosuppressive therapy. For the latter, mesenchymal stem cells are increasingly applied for the treatment of autoimmune diseases.
3. Safety of manipulated stem cells, ie cells after various kinds of manipulations (cultivation, expansion, differentiation) requires deeper research and improvement of protocols of obtaining preparations containing such cells.
4. There is established risk of malignant disorders in clinical use of pluripotent stem cells, which include embryonic and induced pluripotent stem cells.
It is worth noting that to date, stem cells are increasingly seen as a new weapon to fight cancer.
High-dose chemotherapy followed by stem cell transplantation, which has become the «gold standard» in the treatment of some kinds of blood cancer, at the moment, are increasingly used to treat a variety of solid tumors, in particular ovary, breast, testicular, lung cancer etc. High hopes of scientists in the fight against malignant diseases are associated with the use of T-lymphocytes of umbilical cord blood.
In preparing the material the following sources were used:
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7. Proceedings of the World Congress on Cord Blood and Innovative Approaches to the Treatment of Sickle-Cell Disease, Monaco, 2014.