Prognosis and survival for childhood non-Hodgkin lymphoma

If your child has non-Hodgkin lymphoma (NHL), you will have questions about their prognosis. A prognosis is the doctor’s best estimate of how cancer will affect someone and how it will respond to treatment. Prognosis and survival depend on many factors. Only a doctor familiar with your child’s medical history, the type of NHL, the stage and risk group and other features of the cancer, the treatments chosen and the response to treatment can put all of this information together with survival statistics to arrive at a prognosis.

A prognostic factor is an aspect of the cancer or a characteristic of the child that the doctor will consider when making a prognosis. A predictive factor influences how a cancer will respond to a certain treatment. Prognostic and predictive factors are often discussed together. They both play a part in deciding on a treatment plan and a prognosis.

The following are prognostic and predictive factors for childhood NHL.

Children with NHL that responds well to the first treatments given (called first-line therapy) have a better prognosis than children with NHL that responds poorly.

Children with early stage (stage 1 or 2) NHL have a slightly more favourable prognosis. Children with advanced (stage 3 or 4) NHL have a slightly poorer prognosis.

Lactate dehydrogenase (LDH) levels can give the doctors an idea of how much cancer is in the body (called the tumour burden). A higher LDH level is usually linked with a greater tumour burden. LDH is often higher than normal in children with a fast-growing lymphoma.

Lymphoma that is only in the lymph nodes or lymphatic tissue where it started (called the primary site) is more easily treated and has a more favourable prognosis. Lymphoma has a less favourable prognosis when it has spread outside the primary site to organs, such as the lung, liver or spleen.

Some children with NHL in the mediastinum (chest) may have a higher risk of early treatment-related side effects and may need more intensive treatment.

Children with NHL in the brain and spinal cord (called the central nervous system, or CNS) or in the bone marrow have a higher risk that the cancer will come back (recur) and need more intensive treatment.

Certain chromosome changes in the cancer cells can affect the prognosis for children with NHL, depending on the type.

• Children with Burkitt lymphoma who have a gain of 7q or deletion of 13q may have a poorer outcome on certain chemotherapy treatment plans (protocols). Children with a lot of chromosome changes (called a complex karyotype) may also have a poorer outcome.
• Children with diffuse large B-cell lymphoma and chromosomal rearrangement at MYC may have a poorer prognosis.
• Children with T-cell lymphoblastic lymphoma with loss of heterozygosity (LOH) at chromosome 6q may have a poorer prognosis. LOH is when one allele (form) of a gene in the cancer cells stops working. This can mean that a gene that normally helps limit the growth of cancer cells (called a tumour-suppressor gene) stops working.
• Children with T-cell lymphoblastic lymphoma with NOTCH1 mutations have a more favourable prognosis.
• Children with T-cell lymphoblastic lymphoma with PTEN mutations have a poorer prognosis, particularly when it is combined with LOH at chromosome 6q or when NOTCH1 is not mutated.
• Children with anaplastic large cell lymphoma (ALCL) who have anaplastic lymphoma kinase (ALK) in lymphoma cells (called ALK-positiveALCL) have a better prognosis and higher survival rates. Children with lymphoma cells that don’t have ALK or are ALK-negative tend to be diagnosed at a later stage and have a poorer prognosis.

NHL in infants is rare, but infants diagnosed with NHL tend to have a poorer prognosis than older children with NHL. Teenagers with Burkitt’s lymphoma used to have poorer outcomes than younger children, but with more intense therapy the outcomes are now similar. Teenagers with T-cell lymphoblastic lymphoma may have a poorer prognosis than younger children with the disease.

Children with a cancer predisposition syndrome or who are born with an immunodeficiency syndrome and develop NHL in childhood appear to have a poorer prognosis. Treatment may be tailored for these children.