Bone Marrow Transplant clinical outcomes

The Bone Marrow Transplant (BMT) Unit runs a comprehensive stem cell transplant (SCT) service for children with life-threatening diseases.

These include:

• leukaemia
• solid tumours
• bone marrow failure
• immunodeficiency diseases
• inherited metabolic disorders
• autoimmune or immune dysregulatory diseases

The BMT Unit is the largest paediatric BMT centre in the UK and now performs approximately 90 transplant procedures every year.

We measure our transplant outcomes in a range of ways including survival for all conditions treated, survival by groups of similar conditions, and complications of treatment.

‘Overall survival’ is a measure of survival, whether the patient is free from the disease or not.

An allograft is a transplant of an organ, tissue or cells from one person to another where donor and recipient’s genotypes are different (ie not an identical twin). This measure shows survival in all patients who underwent an allograft transplant. Types of conditions treated include immunodeficiencies, metabolic conditions, gastrointestinal conditions, malignant and non-malignant conditions of the blood, cancers and rheumatic conditions.

Definition: Rate/percentage of patients alive at one year after allograft.

Table 1.1 Patients survival one year after allograft by year, 2013 to 2022

It is important to note that overall survival rates can be influenced by all mortality and is not just related to transplant mortality. For example, if a patient died for a reason unrelated to their health condition, this would be counted.

‘Overall survival’ is a measure of survival, whether the patient is free from the disease or not.

This measure shows overall survival rates for patients treated with stem cell transplantation for malignancies, including acute lymphoblastic leukaemia, acute myeloid leukaemia, chronic myeloid leukaemia, juvenile myelomonocytic leukaemia, myelodysplastic syndromes, and non-hodgkin lymphoma.

Malignancies have the lowest overall survival rate of all conditions treated by stem cell transplantation because children who have been pre-treated with a lot of chemotherapy, can experience more toxicity during SCT. Ongoing clinical research seeks to learn more about how to treat these conditions to improve survival rates.

Definition: Rate/percentage of patients alive at one year after allograft to treat malignancies.

Table 2.1 patients survival one year after allograft to treat malignancies by year, 2013 to 2022

Disease-free survival’ is a measure of survival, counting only those patients who are alive and free from the disease they received treatment for.

This measure shows disease-free survival rates for patients treated with stem cell transplantation for malignancies, including acute lymphoblastic leukaemia, acute myeloid leukaemia, chronic myeloid leukaemia, juvenile myelomonocytic leukaemia, myelodysplastic syndromes, and non-hodgkin lymphoma.

Malignancies have the lowest disease-free survival rate of all conditions treated by stem cell transplantation because sometimes malignancies can relapse (recur) despite a successful transplant. Ongoing clinical research seeks to learn more about how to treat these conditions to improve survival rates.

Definition: Rate/percentage of patients alive and disease-free at one year after allograft to treat malignancies.

Table 3.1 Patients alive and disease-free at one year after allograft to treat malignancies by year, 2013 to 2022

Graft-versus-host disease (GvHD) is the most common complication following SCT from a related or unrelated donor. When GvHD occurs, the immune cells (called T-cells) of the donor attack new cells in the transplant recipient’s body causing a skin rash (attack on skin), diarrhoea and vomiting (attack on the gut, or jaundice (attack on the liver).

GVHD is graded according to its severity. Grade 3 and 4 are the most severe grades. Morbidity (ill health) and mortality (death) is higher in grades 3 and 4 GVHD.

Definition: Number/percentage of patients who had grade 3 or 4 GvHD, who had a day 0 (ie transplant start) from prior calendar year when data collected for January audit.

Table 4.1 Patients who had grade 3 or 4 GvHD by year, 2013 to 2022

To prevent the identification of individual patients, where there are low numbers of patients ie fewer than five, exact numbers are not shown.

Based on international publications, rates of up to 10% grade 3 and 4 GvHD may be expected following unrelated donor transplants.

Patients who have received an SCT have a lower immunity for several months after treatment. This means they are more vulnerable to infections. During this time, our children and young people are unable to return to school.

We reviewed our data on the number of patients who were able to return to school. For the year 2022/23, 84% (21/25) of our children and young people returned to full-time education within one year of treatment. Of the 16% that had not returned to school full-time within one year, all had returned within two years.

Table 5.1 Percentage of post-SCT patients who have returned to school full time within the reporting period, April 2022 to March 2023

Numerator: Number of post-SCT school-age patients in the reporting period who have returned to school full time within 12 months of their BMT.

Denominator: Number of school-age patients who reached 12 months post-SCT within the reporting period.

*Where a child or young person needed a second SCT within 12 months of the first SCT, only the first SCT is counted for the purposes of this measure. Definition of school includes mainstream school, specialist educational school, and home school.