During a stem cell transplantation or autotransplantation, the patient receives high chemotherapy dosage which is sometimes done to the entire body to get rid of the cells that are in the bone marrow (including the myeloma cells). Afterwards, the patient receives new stem cells to form blood.
Initially, bone marrow transplant was a process in which the new stem cells were drawn from the bone marrow during the early development of cell transplants. Currently, stem cells are mostly drawn from the blood, a peripheral blood stem cell transplant.
Multiple myeloma is usually treated by stem cell transplant. The number of myeloma cells in the patient’s body is minimized by drug treatment before the transplant.
There are two types of stem cell transplants - autologous and allogenic transplants.
Autologous transplants are done at the time when myeloma is first diagnosed and also after relapse. This method of treatment is given to all patients below the age of 70 who are just diagnosed with multiple myeloma. Autologous transplants do not guarantee cure, however the overall survival rate and event-free survival rate in this treatment is more compared to chemotherapy.
Selection criteria for transplant are mainly the ability to transplant safely, age and renal function.
In autologous stem cell transplant, before the transplant, the patient’s stem cells are removed from bone marrow, or outlying blood and the cells are stored up to when they will be required for the transplant. The myeloma patient’s cancer cells are killed by treatment such as high-dose chemotherapy, at times with the emission of energy as electromagnetic waves. The kept stem cells are returned to the patient’s blood when the therapy is complete.
Patients with multiple myeloma commonly receive this kind of transplant. However, it doesn’t cure the cancer. Myeloma occurs again after an autologous transplant since it only makes the disease disappear for a while.
Patients with multiple myeloma are advised by some doctors to have 2 autologous transplants, 6 to 12 months apart. This procedure is referred to as tandem transplant. Studies indicate that this may assist some patients better than one transplant. Its disadvantage is that it is riskier since it has more negative effects.
Thus, single and tandem transplants benefit the myeloma patient by aiding in the management of myeloma. Stem cells are collected in advance for a tandem transplant later on.
In this kind of cell transplant, the patient receives stem cells responsible for forming blood formation from another person (donor). The treatment is more effective when the donor’s cells are similar to victim’s cell type, and the donor is a close relative like a sibling.
Despite being better at destroying cancer, allogeneic transplants are more dangerous than autologous transplants (graft vs. tumor effect). Studies also show that, in the short term, multiple myeloma patients who received autologous transplants performed better than those who had allogeneic transplants. Currently, allogeneic transplants which may be applied as one of the clinical trials are not recognized as a common myeloma treatment.
Autologous vs Allogeneic
Allogeneic transplantation is the only treatment that promises long-term control of multiple myeloma, but the risk that accompanies it makes it fit only for clinical trials.
Reduced-intensity allogeneic transplants have now improved the chances of survival, but the rate of relapse has increased.
Thus, autologous transplant and a reduced-intensity allograft is the best treatment to reduce relapse at present. Recent advancements in supportive care help manage the side effects very well. Thus, the autologous transplant method has improved a lot.
The early cell transplant’s side effects are more severe but similar to those in chemotherapy and radiation. Low blood counts, which makes the patient vulnerable to infections and bleeding is one of the most severe side effects.
Graft-versus-host disease (or GVHD)
Graft-versus-host disease (or GVHD) is the most severe allogeneic transplants’ side effect. GVHD happens when the patient’s tissues are attacked by the donors’ immune cells after they perceive them as foreign. GVHD can be fatal and can affect any body part.
GvHD can sometimes be mild, but at other times, very serious.
The following are its symptoms:
- Skin rash
- Itching and scaly skin
- Hair loss
- Abdominal cramps
- Liver damage
- Adverse effects on esophagus and lungs
GvHD incidences are high where there is a mismatch between you and the donor. High doses of chemotherapy and radiation before transplant increases the risk.
A combination of drugs such as antibacterial, antiviral, anti-fungal and steroids combined with support therapies are necessary to lessen the side effects.
Transplantation and high-dose chemotherapy have the same side effects which include vomiting, diarrhea, mucositis (inflammation of the digestive tract and the mouth’s lining) nausea, and fatigue. There is a higher chance of getting an infection as well since the chemotherapy of high-dose strikes healthy, disease-brawling cells together with cancer causing cells. Though less common, the cell transplant can damage organs such as lungs, liver, and kidneys.
The immune system then takes longer time to recover from these side effects. They also become susceptible to various infections for a long time. After the transplant, antibiotics are given to patients for some time to protect them from infections. This can prevent them from contracting diseases such as pneumonia, bacterial infections and fungal infections. Herpes, which is a common side effect of high dose chemotherapy and autologous stem cell transplant, can also be prevented.
Sometimes, though rarely, patients complain of cataracts, infertility and new secondary cancers long after the original cancer.
Complications of Transplantation
A relapse of cancer is the major complication of transplantation. Relapses occur when all the cancer cells are not killed by transplantation. It can occur even many years after transplant.
In case of some cancers, relapse rate even for autologous transplants is 50 percent.
Thus, we can conclude that high dose chemotherapy and autologous stem cell transplant is very important to treat myeloma as it improves the cure rate, the overall survival rate and the rate of incidence-free survival. Transplantation is cost effective and can be done at any stage of multiple myeloma. Patients discuss the benefits and risks of the treatment with their doctors before beginning treatment.