Long-term follow-up of an age-adapted C5R protocol followed by radiotherapy in 99 newly diagnosed primary CNS lymphomas: a prospective multicentric phase II study of the Groupe d'Etude des Lymphomes de l'Adulte (GELA).

BACKGROUND

This prospective multicentric phase II study aimed to confirm the results of the C5R protocol of high-dose methotrexate (MTX)-based chemotherapy (CT) for immunocompetent primary central nervous system lymphoma.

PATIENTS AND METHODS

A total of 99 patients received age-adapted CT (C5R protocol) followed by radiotherapy. Patients younger than 61 years (group 1, n = 45) received the full C5R with MTX, doxorubicin, vincristine, cyclophosphamide, and cytarabine. Patients aged 61-70 years (group 2, n = 36) received reduced doses. Patients older than 70 years (group 3, n = 18) received four courses of MTX, cyclophosphamide, and etoposide.

RESULTS

Median age was 63 years and 51% of patients had performance status of more than one. Seventeen patients died of toxicity during CT. Complete response was achieved in 56%, 53%, and 28% of patients in groups 1, 2, and 3, respectively. With a median follow-up of 83 months, the 5-year progression-free survival was 31%, 28%, and 11% and the 5-year overall survival 42%, 31%, and 17% for groups 1, 2, and 3, respectively. Leukoencephalopathy occurred in 32% of assessable patients, in both group 1 and groups 2-3.

CONCLUSION

The C5R protocol was feasible in the multicentric setting with favorable long-term survival in patients younger than 60 years. Despite dose adaptation, results in older patients were disappointing.