The following factors contribute to the adverse effects of a stem cell or bone marrow transplant:
- If you have high-dose chemotherapy targeted medicines, use them.
- If you additionally receive whole-body radiation as part of your treatment, you may have additional side effects. Total body irradiation, or TBI, is another term for whole body radiotherapy.
All of the adverse effects occur at their peak just after your high-dose chemotherapy and for a few weeks following. You will begin to feel better when your blood counts begin to grow (engraftment). Inform your team if you have any adverse effects. They can be of great assistance to you.
In the long run, these therapies frequently result in infertility.
Even though the treatment option has several side effects, BMT is one of the most important forms of treatment. The cost of bone marrow transplant is quite expensive as this is a complex treatment and requires experienced medical professionals to perform such surgery.
Risks associated with BMT
There are many risk factors associated with BMT. These include age, gender, human leukocyte antigen (HLA)-matching, conditioning regimen, stem cell source, intensity of conditioning regimen, patient comorbidities, cytomegalovirus serostatus, cytomegaloviral load, timing of BMT relative to starting chemotherapy, and type of immune suppression.
In general, older patients who receive their first autologous BMT appear to suffer more severe acute toxicity and chronic GVHD than younger recipients. Older age has not been shown to affect the outcome of allogeneic BMT, whereas it adversely affects survival after autologous BMT.
- Graft versus host Diseases
The side effects of bone marrow transplantation (BMT) are well known, including graft-versus-host disease (GVHD), infection, immunosuppression, and relapse. GVHD occurs when donor T cells recognize host antigens as foreign and attack host organs and tissues. Other less frequent complications include hemorrhage, thrombocytopenia, and mucocutaneous reactions.
The exact incidence of these complications is difficult to determine due to retrospective studies using patient self-report rather than standardized data collection methods. In addition, the diagnosis and management of some complications may have changed over time.
- Infection
Infection is the most common complication of BMT. Patients undergoing allogeneic BMT are at increased risk for bacterial infections and reactivation of latent viruses, including herpes simplex virus (HSV). In contrast, HSV reactivation is uncommon among patients receiving autologous BMT; however, they are at increased risk for viral pneumonitis caused by adenoviruses, parainfluenza virus, respiratory syncytial virus (RSV), and measles.
- Graft failure
Graft failure occurs if the bone marrow does not engraft successfully. The major causes of graft failure include insufficient numbers of hematopoietic progenitor cells in the donor marrow, poor quality of the marrow, inadequate conditioning regimen, and delayed engraftment. Additional causes include graft-versus-graft disease, radiation damage, and lack of HLA matching between recipient and donor.
- Relapse of cancer
Relapse of leukemia is defined as recurrence of leukemia following apparent clinical remission. Relapses occur in 30% to 40% of patients with acute myeloid leukemia (AML) who achieve complete remission. Relapses occur earlier in AML than in other forms of leukemia, mainly within 1 year of achieving complete remission. Relapses tend to present as refractory cytolytic leukemia (RCL); however, sometimes relapsing cases are diagnosed as AML. Relapses of AML are thought to result from persistence of minimal residual disease (MRD) in normal tissues or undetected tumor cells in the marrow, possibly due to ineffective treatment and/or incomplete eradication of MRD.
Survivors of childhood cancer have a 20% chance of developing second malignancies. Survivors of Hodgkin’s disease, non-Hodgkin’s lymphoma, and retinoblastoma have a higher risk of developing solid tumors compared to the general population. Survivors of Wilms’ tumor have an approximately 50% chance of developing renal carcinoma. Survivors of breast cancer have a 2% chance of developing contralateral breast cancer, and survivors of colorectal cancer have a 15% chance. The relative risk of second cancers increases with increasing latency period. Second malignancies occur later in life than primary cancer. However, the risk remains elevated throughout adulthood. The cumulative probability of developing a second cancer at 40 years is 19%.
- Second malignancy
Second neoplasms develop more often in patients who received high doses of alkylating agents or total body irradiation. Exposures to ionizing radiation increase the risk of second cancers. Chemotherapy regimens containing cyclophosphamide and anthracyclines are associated with increased prevalence of thyroid, breast, ovarian, uterine, testicular, bladder, brain, stomach, and skin cancers. Leukemia survivors treated with alkylating agents are at greater risk of developing solid tumors than those treated with antimetabolites.
Second malignant neoplasms are classified according to the International Classification of Diseases for Oncology (ICDO): synchronous, metachronous, and unspecified. Synchronous neoplasms are those occurring simultaneously with the initial malignancy. Metachronous neoplasms develop months to years after the initial cancer. Unspecified neoplasms refer to any type of malignancy that cannot be categorized under either category.
Synchronous neoplasms must be distinguished from metastatic lesions. Metastatic neoplasms occur when microscopic tumor cells spread from the primary site to distant sites in the same organ system or different ones. Metastasis accounts for 90% of deaths from malignancies.
Therapy-related neoplasms are a group of rare, late complications of cancer treatments. Radiotherapy, chemotherapy, and hormonal therapies cause DNA damage and genetic mutations. These changes lead to accumulation of abnormal cells and development of cancer.
What can be done?
Immunosuppressive therapy is necessary to prevent rejection of the transplanted bone marrow cells. Steroids decrease the number of circulating lymphocytes and monocytes, resulting in decreased cellular immunity. Mycophenolate mofetil inhibits purine synthesis and prevents proliferation of lymphocytes. Cyclosporine A interferes with mitosis of activated T cells and suppresses humoral immunity. Anti-thymocyte globulin depletes mature T cells and decreases both cellular and humoral immunity.
Patients with a history of prior exposure to blood products, especially platelets and red blood cells, should avoid transfusions until they are cleared of the previous exposure. Transfusion of fresh frozen plasma carries risks similar to those of whole blood donors, including transmission of infectious agents and adverse reactions.
