EBV-driven lymphoid neoplasms associated with pediatric ALL maintenance therapy.

Area of Science:

• Pediatric Oncology
• Hematology
• Immunology

Background:

• Second malignancies are rare after childhood acute lymphoblastic leukemia (ALL).
• The causes and management of most post-ALL neoplasms are unclear.
• This study focuses on non-Hodgkin lymphomas (NHL) after pediatric ALL, excluding stem cell transplants.

Purpose of the Study:

• To comprehensively report on NHL developing after pediatric ALL therapy.
• To investigate the characteristics, outcomes, and associations of these secondary NHLs.
• To highlight the role of immunodeficiency in post-ALL lymphoid neoplasms.

Main Methods:

• Analysis of 85 patients with NHL post-ALL from 12 collaborative pediatric ALL trials (1980-2018).
• Histopathological review focusing on immunodeficiency markers and Epstein-Barr virus (EBV).
• Literature search for additional cases of post-ALL lymphoid neoplasms.

Main Results:

• Mature B-cell lymphoproliferations were the dominant NHL subtype (56/85 cases).
• 82% of these NHLs occurred during or within 6 months of maintenance therapy.
• 65% of investigated lymphoid neoplasms showed immunodeficiency-associated features, often EBV-driven. 5-year survival was 67.4% for 66 patients.

Conclusions:

• A significant proportion of lymphoid neoplasms post-ALL are associated with an immunodeficient state, potentially triggered by therapy.
• Early diagnosis and awareness of this underrecognized entity are critical for effective management.
• Concurrent hemophagocytic lymphohistiocytosis is linked to poorer outcomes.