Treatment options for pediatric lymphoblastic lymphoma

This trial examined intensifying treatment in children with stage 3 or 4 lymphoblastic lymphoma. This study also compared treatments meant to prevent central nervous system involvement. The authors determined that the outcomes were similar regardless of treatment type.

Lymphoblastic lymphoma is the second most common form of non-Hodgkin lymphoma in children. Treatment generally includes a first treatment phase (induction). This may include a combination of chemotherapies. Induction is followed by consolidation, a second treatment phase. Maintenance therapy is long-term treatment to prevent relapse. These phases also may include combinations of chemotherapies.

Most patients also receive treatment to prevent lymphoma spread to the central nervous system (CNS). This commonly involves methotrexate (MTX, Trexall) delivered directly to the spine. This is known as intrathecal chemotherapy (IT). Some studies have shown success without IT MTX in the maintenance phase. These patients were treated with oral MTX alone. It is not clear which strategy is more effective.

Studies have also shown that an early response to treatment is associated with improved outcomes. It is not clear whether early intensification of treatment would improve response and outcome.

The current study focused on both early treatment intensification and maintenance-phase CNS prevention. 254 patients were included. 12 patients already had CNS involvement at the start of the study.

Patients were randomly assigned to one of four groups. All groups were treated with a combination of steroids, chemotherapy, and IT during induction. Two groups were also treated with intensified chemotherapy. Two groups were treated with IT MTX during maintenance. The other two groups were treated with oral MTX.

Five-year event free survival (EFS, time from treatment until an event such as relapse, progression or death) was similar for all groups (80% to 84%). Five-year overall survival (OS, time from treatment until death from any cause) was also similar for all groups (84% to 88%). In patients with CNS involvement at diagnosis, 5-year EFS was 63% and 5-year OS was 81%.

Overall, older patients (age 10 or older) had a significantly lower 5-year EFS (76%) compared to younger patients (87%). Five-year OS was also significantly lower in older patients (78%) compared to younger (93%).

Patients who responded after 2 weeks of induction treatment (based on a CT scan) had better OS. OS was 93% of patients who achieved a complete response (no sign of active disease) were alive after 5 years. This was compared to 60% of those who saw no change in cancer activity (stable disease).

This study concluded that there was no significant difference in outcome based on type of CNS prevention or with treatment intensification.