CYCLOPHOSPHAMIDE, DOXORUBICIN, VINCRISTINE, AND PREDNISONE FOR PRIMARY CENTRAL-NERVOUS-SYSTEM LYMPHOMA - SHORT-DURATION RESPONSE AND MULTIFOCAL INTRACEREBRAL RECURRENCE PRECEDING RADIOTHERAPY

The activity of cyclophosphamide, doxorubicin, vincristine, and predni sone (CHOP) in the treatment of primary central nervous system lymphom a (PCNSL) prior to radiotherapy was studied in six patients. Primary l esions were reduced by 80% or more on contrast-enhancing cross-section al area in four patients and to a lesser extent in two others after tw o cycles of chemotherapy. The primary lesion sites demonstrated no con trast enhancement in the three patients who completed four cycles of t herapy. However, concurrent with response at the primary disease sites , multiple lesions occurred at distant, noncontiguous CNS parenchymal sites in five patients after two to four cycles of chemotherapy. Media n survival was 8.5 months for the six enrolled patients and 16.5 month s for the four patients completing craniospinal radiotherapy. PCNSL is highly responsive to standard systemic non-Hodgkin's lymphoma chemoth erapy regimens, but the pattern and rapidity of relapse suggest mechan isms of failure including inherent or rapidly evolving antineoplastic drug resistance and perhaps limited drug delivery to occult sites of d isease in the brain.