This four-part series is written by Edward Agura, MD, an advisory panel member for the Cancer.Net Editorial Board. Dr. Agura is Director of the Program in Blood and Marrow Transplant at Baylor University Medical Center in Dallas, Texas.

This is the second article in a four-part series on bone marrow and stem cell transplantation. The series will prepare you to ask your transplant team meaningful questions and help you to understand the answers. This article will discuss special types of transplantation and provide you with a transplant timeline.

The two most common types of transplants are autologous (AUTO), in which the patient's own bone marrow is used, and allogeneic (ALLO), when another person is the donor of the bone marrow. If neither an AUTO nor ALLO transplant is possible, there may be other options available. Special types of transplantation are listed below.

Umbilical cord blood donor. Some patients cannot find a suitable living donor, either due to lack of time or lack of suitable tissue matches. For this reason, an umbilical cord blood transplant is being researched and developed. Cord blood is the cup of blood that remains in the placenta and umbilical cord after a baby is born. It is the baby's own blood, not the blood of the mother. If that blood is saved, tested, and put into a tissue bank, it may be used for a patient who cannot find a donor. Cord blood cells have special properties. They are particularly rich in hematopoietic stem cells and have the property of growing much better and faster than stem cells from a living adult donor. It is also believed, but not fully proven, that such stem cells may cause fewer complications such as graft-versus-host disease (GVHD). But, there are also potential drawbacks. Cord blood can only be used once, the small quantity may not be enough for an adult patient, and the rate of infections may be higher. In general, the use of cord blood remains specialized, even among the community of transplant centers, and not all centers are able to offer this type of transplant to patients. A patient who cannot find a donor should ask his or her transplant team whether a cord blood transplant is an option.

Mini-transplant (nonablative or reduced-intensity transplant). A mini-transplant is a transplant done with mild, rather than strong, treatment prior to the infusion of donor cells. Large transplant centers will offer this approach, if the circumstances fit. The principal advantage of this transplant is fewer side effects early on in the process. For example, there may be no hair loss, fewer blood transfusions, and less time in the hospital. However, the main disadvantage is a less powerful anticancer treatment. Patients in immediate danger from an aggressive cancer are not well-served by this approach. On the other hand, for certain slow-growing cancers, this method may offer the perfect balance of cancer treatment with a lower risk of side effects.

Parent/child and haplotype mismatched stem cell transplant. This is a rare type of transplant, not performed by most centers in the United States because of a high complication rate. Yet, in extreme cases of relapsed leukemia where no matched donors can be easily found, it may be the only option. For this type of transplant, the donor is a family member who is only a 50% match, rather than the 100% match usually sought after. Parents, children, or siblings may be used. The risks are higher due to the lower percentage of tissue match. GVHD, infections, and failure of donor cells to grow happen far more often than with matched-donor transplantation.

Outpatient transplantation. Nowadays, patients are less ill during the transplant process for a variety of reasons. Mini-transplants have reduced the intensity of the treatment and the side effects. Scientific advancements in tissue typing, anti-infective care, and supportive care have reduced illness related to transplants. All of these reasons have helped reduce the need for hospitalization. It is now possible at some centers to perform an entire transplant procedure without any planned overnight stays in the hospital. This is a very good topic to discuss during the time of transplant consultation, to see if this is an option.

A transplant timeline

Every patient has questions about transplant timing, duration, and time of recovery. Some have to do with anticipated family life events (births, graduations, etc.); others relate to economics and return to work.

This section illustrates the timeline of two typical transplants, an AUTO and ALLO. The major steps or phases are described for each. One phase usually leads directly to the next, but some phases (such as stem cell collection) may be done a long time ahead. Phases are consecutive.

AUTO transplant timeline

Phase I: Bone marrow/blood stem cell collection
involves: surgical placement of a transplant catheter (a thin tube temporarily put into a large vein to make injections easier) (1 day); injections of white blood cell growth factor (5 days); bone marrow harvest surgery (1 day) OR blood collections through apheresis (the process of giving only select blood components: platelets, plasma, red cells, granulocytes, or a combination of these) (3 hours/day for 1 to 5 days)
overall duration: 1 to 2 weeks
where: outpatient

Phase II: Transplant treatment (chemotherapy/radiation therapy)
involves: chemotherapy and/or radiation therapy
overall duration: 5 to 7 days
where: outpatient or inpatient

Phase III: Stem cell transfusion/infusion (transplant day)
involves: transfusion of stem cells by intravenous (IV) injection (1 hour)
overall duration: 1 day
where: outpatient or inpatient

Phase IV: Recovery
involves: antibiotics, blood transfusions, growth factors, symptom management
overall duration: 2 weeks
where: outpatient or inpatient

ALLO transplant timeline

Phase I: (Donor) Bone marrow/blood stem cell collection
involves: injections of white blood cell growth factor (5 days); bone marrow harvest surgery (1 day) OR blood collections via apheresis (3 hours/day for 1 to 2 days)
overall duration: 1 week
where: outpatient

Phase II: (Patient) Transplant treatment (chemotherapy/radiation therapy)
involves: chemotherapy and/or radiation therapy
overall duration: 5 to 7 days
where: outpatient or inpatient

Phase III: Stem cell transfusion/infusion (transplant day)
involves: transfusion of stem cells by intravenous (IV) injection (1 hour)
overall duration: 1 day
where: outpatient or inpatient

Phase IV: Recovery
involves: medications (immunosuppressives, antibiotics, growth factors) and for symptom management, blood transfusions and fluids
overall duration: 8 to 12 weeks
where: mostly outpatient, some inpatient

The timelines for special types of transplants, such as those outlined in this article, may be similar or different to the two above. In all cases, patients are encouraged to discuss their treatment timelines with the transplant team as part of their preparation for the process.

Additional Resources

Bone Marrow and Cord Blood Donation and Transplantation from the U.S. Department of Health and Human Services

More Information

Part I: Understanding Bone Marrow and Stem Cell Transplantation

Part III: Side Effects of Bone Marrow and Stem Cell Transplantation

Part IV: Questions and Answers About Bone Marrow and Stem Cell Transplantation

Donating Bone Marrow