High-dose methotrexate-leucovorin rescue therapy: selected application in non-Hodgkin's lymphoma.

Methotrexate with leucovorin rescue (HDMTX-LV rescue), has been used to treat solid tumors and non-Hodgkin's lymphomas (NHL). We studied the use of HDMTX-LV rescue in patients with widespread NHL with histologic diagnosis of diffuse poorly differentiated lymphocytic and diffuse histiocytic including involvement of the central nervous system (CNS) and/or bone marrow. The prognosis with conventional chemotherapy is extremely poor. Three patients have bone marrow involvement, 2 patients CNS, and 2 both. These patients were unresponsive to conventional chemotherapy and had a rapid progression of their disease. Therapy with HDMTX-LV rescue induced responses in 5 patients: 2 patients achieved a complete remission and three a partial remission. Regression of CNS involvement was observed in 3 patients; bone marrow toxicity was not observed. Only 1 patient failed to respond. These data suggest that HDMTX-LV rescue may be useful as primary therapy in lymphoma patients with CNS and/or bone marrow involvement.