Reduced neurotoxicity with combined treatment of high-dose methotrexate, cyclophosphamide, doxorubicin, vincristine and prednisolone (M-CHOP) and deferred radiotherapy for primary central nervous system lymphoma

Objective Although high-dose methotrexate and whole-brain radiation therapy (WBRT) is the current standard for primary central nervous system lymphoma (PCNSL), it has a limited response rate and produces radiation-induced neurotoxicity. We report the effect of a combined treatment of high-dose methotrexate, cyclophosphamide, doxorubicin, vincristine and prednisolone (M-CHOP) for immunocompetent patients with PCNSL.

Methods We analyzed 24 patients who had received M-CHOP administered in 28-day cycles with or without WBRT. The response rate to M-CHOP, overall survival (OS), and recurrence-free survival (RFS) were analyzed.

Results Nine patients were treated with M-CHOP plus WBRT and 15 patients were treated with M-CHOP alone. Twenty-one patients achieved a complete response and three patients achieved a partial response to M-CHOP, for a 100% response rate. With a median follow-up of 70 months, the median OS and RFS were 33 and 13 months, respectively. The median OS for patients treated with M-CHOP plus WBRT and M-CHOP alone was 33 and 32 months, respectively. Of the 13 patients whose age was above 65 years, the median OS for the M-CHOP plus WBRT group (two patients) and the M-CHOP alone group (11 patients) was 14 and 32 months, respectively. Toxicities related to M-CHOP were mostly hematologic and generally mild to moderate. Two patients whose age was above 65 years in the M-CHOP plus WBRT group developed neurotoxicity.

Conclusion Combined treatment with M-CHOP was well tolerated and produced a high response rate. Deferring WBRT was associated with reduced neurotoxicity without worsening the prognosis, especially in elderly patients.