The Pediatric Acute Leukemia (PedAL) Screening Trial - A Study to Test Bone Marrow and Blood in Children With Leukemia That Has Come Back After Treatment or Is Difficult to Treat - A Leukemia & Lymphoma Society and Children's Oncology Group Study

This study is looking for children and young people who are under 22 years old at the time they join. They must have certain types of leukaemia that have either come back after treatment, or have been hard to treat.

Specifically, this includes various forms of acute leukaemia (like Acute Lymphoblastic Leukaemia or Acute Myeloid Leukaemia), as well as Myelodysplastic Syndrome or Juvenile Myelomonocytic Leukaemia, especially if these conditions have returned or are proving difficult to manage. If you're not sure if your child's specific condition fits, it's best to ask their doctor.

All families and patients (if they are old enough) will need to give their permission in writing to take part in the study. Your medical team will explain everything fully before you make any decisions.

If you decide to take part, your child will have samples of their blood and/or bone marrow collected at the start of the study. These collections might also happen again during their treatment, or if their leukaemia returns or isn't responding well to treatment.

The study itself involves just the collection of these samples and no new medications or treatments will be given as part of *this* particular study. After the study collections are completed, the research team will keep in touch. They will check in every three months for the first two years, then every six months for another three years. This is to gather long-term information about the leukaemia, but it mostly involves just keeping records.