Late relapse in primary central nervous system lymphoma: clonal persistence

Area of Science:

• Neuro-oncology
• Hematology
• Clinical Medicine

Background:

• Primary central nervous system lymphoma (PCNSL) typically recurs within 2 years of initial treatment.
• Late relapse (≥5 years post-diagnosis) is considered rare in PCNSL.
• Understanding late relapse patterns is crucial for long-term patient management.

Purpose of the Study:

• To evaluate the characteristics and outcomes of patients with late relapse of PCNSL.
• To determine the frequency of late relapses in a PCNSL cohort.
• To assess the efficacy of salvage therapy for late PCNSL recurrence.

Main Methods:

• Retrospective analysis of 378 PCNSL patients.
• Identification of 10 patients with relapse ≥5 years after initial diagnosis.
• Review of initial diagnosis, treatment, relapse patterns, and salvage therapy response.

Main Results:

• Late relapses accounted for 4% of all recurrences (10 of 230 patients).
• Median time to first late relapse was 7.4 years.
• Most late relapses occurred in the brain; salvage therapy led to complete response in 90% of patients, with a median progression-free survival of 31 months.

Conclusions:

• Late relapses of PCNSL, though infrequent, can occur and are associated with long-term persistence of the lymphoma clone in some cases.
• Patients with late PCNSL relapse demonstrate a favorable response to salvage therapy.
• Effective salvage treatment contributes to prolonged survival in patients experiencing late recurrence.