Autologous Stem Cell TransplantationEdit

Autologous stem cell transplantation (ASCT) is a medical procedure used mainly to treat certain hematologic cancers and, less commonly, select autoimmune diseases. In ASCT, hematopoietic stem cells are collected from the patient, stored, and later reinfused after the patient receives high-dose chemotherapy or radiation intended to eradicate disease in the bone marrow. Because the graft comes from the patient themselves, ASCT avoids the risk of graft-versus-host disease that can accompany donor transplants, and it does not require a matched donor. This makes ASCT a practical option in many settings, particularly for eligible patients with specific diseases such as multiple myeloma and certain lymphomas. The overall goal is to improve disease control, often by allowing higher doses of chemotherapy than would otherwise be tolerable.

The procedure sits within the broader field of stem cell transplantation and is frequently performed with mobilized peripheral blood stem cells, though bone marrow collection is also possible. In modern practice, ASCT has become a standard-of-care option for several diseases, with outcomes that vary by disease, stage, patient age, and comorbidities. Ongoing research continues to refine mobilization strategies, conditioning regimens, and supportive care to maximize benefit and minimize toxicity. See also bone marrow transplantation and peripheral blood stem cell transplantation for related concepts and alternatives.

Indications

ASCT is most commonly used for: - multiple myeloma, where it is a central element of care for eligible patients and can extend progression-free survival and, in some cases, overall survival when combined with modern therapies. See Multiple myeloma. - various forms of lymphoma, including Non-Hodgkin lymphoma and, in selected cases, Hodgkin lymphoma, particularly for patients who are younger or fit enough to tolerate high-dose therapy. See also BEAM regimen as a common conditioning approach in lymphoma. - select leukemias, such as Acute myeloid leukemia and Acute lymphoblastic leukemia, typically in patients who have achieved remission and can tolerate high-dose conditioning. - other cancers in which high-dose chemotherapy with autologous rescue has shown activity, including certain germ cell tumors in the relapsed or refractory setting. - select autoimmune diseases, including some patients with autoimmune disease such as Multiple sclerosis or systemic sclerosis, where controlled data suggest potential benefit in carefully selected cases, though this remains an area of active investigation and discussion.

Eligibility generally depends on disease type and stage, performance status, organ function, and the ability to tolerate high-dose therapy. See neutropenia and fertility preservation for common medical considerations during evaluation.

Procedure

Stem cell mobilization and collection

Stem cells are typically collected after mobilizing them from the marrow into the bloodstream using growth factors such as granulocyte colony-stimulating factor (G-CSF), with or without chemotherapy. The collected cells are then gathered via leukapheresis and processed for storage. In many centers, peripheral blood stem cell collection is the preferred approach due to faster engraftment compared with bone marrow harvest. See Leukapheresis and Peripheral blood stem cell transplantation.

Processing, cryopreservation, and storage

Collected cells are tested for viability, counted, and cryopreserved, usually with a cryoprotectant such as dimethyl sulfoxide (DMSO). They are stored in appropriate conditions until the conditioning regimen is completed. See Cryopreservation and Stem cell transplantation.

Conditioning regimens and transplantation

Patients receive high-dose chemotherapy, and sometimes total body irradiation, to ablate the diseased bone marrow. Common regimens in lymphoma include BEAM (carmustine, etoposide, cytarabine, and melphalan), while myeloma regimens frequently center on high-dose melphalan. The goal is maximal cytoreduction with tolerable toxicity, followed by reinfusion of the patient’s own stem cells to rescue marrow function. See Melphalan and BEAM regimen.

Engraftment, recovery, and early follow-up

After reinfusion, stem cell engraftment resumes, with neutrophil recovery typically occurring in about 10–14 days and platelet recovery following later. Patients require close monitoring for infections, mucositis, organ toxicity, and other complications during the period of marrow suppression. See Engraftment and Neutropenia.

Long-term considerations

Long-term follow-up addresses disease control, late effects of high-dose therapy, fertility considerations, and risks of secondary malignancies or organ toxicity. Survivors may require vaccination updates and ongoing surveillance for relapse. See Fertility preservation and Endocrine disorders as related topics.

Safety and outcomes

ASCT avoids the donor-related risks of allogeneic transplantation, notably graft-versus-host disease, but it does carry risks typical of high-dose chemotherapy and marrow suppression. Complications can include infections during neutropenia, mucositis, renal or hepatic toxicity, cardiovascular strain from conditioning, and, in some cases, fertility impairment. Outcome data vary by disease; for example, in multiple myeloma and certain lymphomas, ASCT improves progression-free survival and may improve overall survival in appropriately selected patients, but it is rarely curative in most diseases. The balance of potential benefit against risks is a central part of the treatment discussion, particularly for older patients or those with significant comorbidities. See Neutropenia, Mucositis, and Fertility preservation for related risks and management.

Controversies and debates

Medical discussions around ASCT focus on patient selection, timing, and the integration of transplantation with newer therapies. Key points include: - Timing and sequencing: Debates persist about the optimal timing of ASCT in diseases like multiple myeloma—whether early transplant offers a meaningful advantage over reserving transplantation for relapse. Trials have shown improvements in progression-free survival with early transplantation, but the impact on long-term overall survival remains nuanced and disease-specific. See Multiple myeloma. - Comparisons with newer therapies: As targeted agents and immunotherapies evolve, the incremental benefit of ASCT is re-evaluated in some settings. Decisions often depend on disease biology, patient preference, access, and cost considerations. See Immunotherapy and Targeted therapy for context. - Autoimmune indications: The use of autologous transplantation for autoimmune diseases is promising in selected patients but remains controversial due to mixed long-term results and variable study quality. See autoimmune disease and Multiple sclerosis for related discussions. - Access and cost: Because ASCT is resource-intensive, access can be uneven, raising questions about equity and health economics. Policymakers and clinicians weigh cost against potential gains in progression-free intervals and quality of life. - Long-term risks: The possibility of late effects, including secondary malignancies and endocrine or fertility issues, informs the risk–benefit calculus, especially in younger patients or those with long life expectancies. See Secondary malignancy and Fertility preservation.