Juvenile Myelomonocytic Leukemia (JMML): Symptoms, Causes, and Treatment

Several treatment options are available for children with JMML.

Stem Cell Transplantation

Stem cells are cells that can develop into different types of cells, including muscle cells and brain cells. Sometimes, they can repair damaged tissues. Hematopoietic stem cells are adult stem cells that come from the bone marrow, and they mature into all types of blood cells.

The Leukemia & Lymphoma Society notes that stem cell transplantation is the only known cure for JMML. All children with JMML who will undergo stem cell transplantation must receive high-dose chemotherapy to destroy the cancer cells and create enough space in the bone marrow for the new stem cells. This chemotherapy will also suppress the body’s immune system to lessen the chances of the body rejecting the donor cells.

About 50 percent of patients achieve long-term remission after stem cell transplantation, but relapses frequently occur, especially within the first year. A second stem cell transplant may cure JMML.

Stem Cell Transplantation Complications and Side Effects

A stem cell transplant can cause complications:

• Rejection The body may see the donated stem cells as foreign and destroy them.
• Graft-versus-host disease The immune cells from the donor see the patient’s healthy cells as foreign and attack them.

Chemotherapy

Chemotherapy isn’t used in JMML for a cure, but it is an option that can be used to address your child’s symptoms while preparing for stem cell transplantation.

Chemotherapy medications are available as pills, injections to the muscle or fat tissue, or direct injections into a vein or the spinal column. There is no best chemotherapy treatment for JMML, according to the American Cancer Society.

Chemotherapy Side Effects

Chemotherapy can kill healthy cells along with cancer cells, causing unwanted side effects. The side effects your child may experience depend on the type of chemo used, the dose, and the length of treatment, and include the following:

• Hair loss
• Fatigue
• Diarrhea
• Nausea and vomiting
• Loss of appetite
• Mouth sores
• Bleeding and bruising
• Risk of infections

Clinical Trials

Your doctor may discuss other options for your child if treatment has not been effective. They may recommend that your child participate in a clinical trial looking at newer drugs for JMML.

Is There a Cure for JMML?

JMML is difficult to treat, but a cure is achieved in about half of cases, according to the National Organization for Rare Disorders. Stem cell transplantation offers the best chance at a cure for JMML, but 30 to 40 percent of people will experience relapse. A cure may be possible with a second stem cell transplant.