Key messages
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As a first treatment for someone with a rare white blood cell cancer (MTCL), giving someone stem cells from another person (alloSCT) rather than their own stem cells (autoSCT) may make little or no difference to their chance of treatment success or survival.
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As an extra treatment for someone who is still ill after earlier treatments for MTCL, giving alloSCT rather than any other treatment may make little or no difference to their chance of treatment success or survival.
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Future studies should look at how best to use alloSCT for MTCL, particularly for different types of MTCL, and when to offer this treatment.
What are mature T-cell lymphomas, and how are they treated?
Mature T-cell lymphomas (MTCLs) are a group of rare blood cancers that affect T-cells (a type of white blood cell). There are several types of MTCL, such as cutaneous T-cell lymphomas (CTCLs), which affect the skin, and non-cutaneous MTCLs, which affect other body parts. Only about half of people with MTCL survive for three years. Traditional cancer treatments that kill cancer cells (chemotherapies) help control the disease for about 30% of people with MTCL.
Stem cells are cells in a person's body that can make copies of themselves and turn into different types of cell. A stem cell transplant replaces damaged cells in a person's body with healthy stem cells, which means they can make healthy blood cells again. If a person's own healthy stem cells can be collected and be used to replace the damaged cells later, this is called autologous stem cell transplantation (autoSCT). Alternatively, healthy stem cells from another person (donor) are used to replace the damaged ones in the person with the disease (allogeneic stem cell transplantation: alloSCT). The new stem cells help the person using the donor's immune system to fight cancer (graft-versus-lymphoma effect). This treatment is particularly helpful for people who have already tried chemotherapy but are still ill.
Using someone else's stem cells can sometimes lead to the new cells attacking the person's body (graft-versus-host disease; GVHD). If this occurs quickly, it is called acute GVHD (aGVHD), whereas if it starts later (or goes on for a long time) it is called chronic GVHD (cGVHD).
What did we want to find out?
We wanted to find out the benefits and risks of alloSCT as a treatment for adults with MTCL. We looked at how well it works and whether it is safe, either when used as a first treatment (first-line) or for people who have already had other treatments but are still ill. We looked at whether treating people with alloSCT improves:
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the chance of surviving (overall survival);
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the chance of surviving without cancer coming back or getting worse (progression-free survival);
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the chance of successful treatment (response rate);
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well-being.
We also looked at the risks of:
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treatment causing the person's death;
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acute or chronic GVHD;
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any unwanted effects.
What did we do?
We searched for studies that investigated alloSCT compared to any other treatment for MTCL. We compared and summarized the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found three studies that involved 222 people with MTCL; one used alloSCT as a first-line treatment, and two used alloSCT for people who had already had other, unsuccessful, treatments first.
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One study compared alloSCT to autoSCT as a first treatment for 103 people and found there may be little to no difference in overall survival, progression-free survival, or unwanted effects, and no effect on the response rate. People who had alloSCT had a higher risk of the treatment causing their death. Most people (84%) with alloSCT developed aGVHD, and nearly half (47%) experienced cGVHD.
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One study compared alloSCT to any other treatment for 102 people with CTCL who were still ill after earlier treatment. There was little to no difference in overall survival or unwanted effects, but progression-free survival may have been longer after alloSCT. 56% of the people with alloSCT had aGVHD, and 31% had cGVHD. However, we are not confident in the evidence from this study. It did not report whether people died from treatment or what the response rate was.
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Another study gave alloSCT to 17 people with non-cutaneous MTCL who were still ill after previous treatment, but did not compare them to another group. The response rate was 76% after one month. 35% had aGVHD and 41% had cGVHD. The study did not report any unwanted effects. Two years later, about 80% of the people were still alive with a progression-free survival of 64%. About 6% had died from the treatment.
What are the limitations of the evidence?
We are not confident in the evidence because the studies were small and did not always report the results for all the people treated.
How up to date is the evidence?
The evidence is up to date to October 2025.
Leer el resumen científico
Objetivos
To assess the benefits and harms of alloSCT in the treatment of MTCL in adults (≥ 18 years old) compared to any other treatment, particularly with respect to its efficacy and safety as first-line therapy, and secondarily, for its efficacy and safety as a salvage option.
Métodos de búsqueda
We searched CENTRAL, MEDLINE, Embase, conference proceedings, and two databases of ongoing trials from January 1990 to October 2025 for prospective and retrospective studies evaluating the role of alloSCT for MTCL.
Conclusiones de los autores
In this systematic review, we identified one RCT of alloSCT as first-line treatment for MTCL, and one Mendelian RCT and one prospectively planned phase-II trial of alloSCT for relapsed or refractory MTCL. We encountered difficulties while extracting data from these studies, because there were major differences in study designs, intervention and control groups. We identified low- to very low-certainty evidence on the effectiveness and safety of alloSCT for adults with MTCL. We had some concerns about the risk of bias in the two RCTs and serious concerns about bias in the phase-II study.
As there are three ongoing studies evaluating alloSCT, mostly for relapsed or refractory MTCL, it is possible that an update of this review will be published in the near future. However, none of the ongoing studies are of an RCT design.
Financiación
Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf, Faculty of Medicine and University Hospital Cologne, University of Cologne.
Registro
Protocol available via DOI 10.1002/14651858.CD014672.
