Histologic progression in non-Hodgkin's lymphoma

Abstract

We retrospectively evaluated the clinical course and biopsy specimens from 515 consecutive non-Hodgkin's lymphoma patients in an attempt to determine the clinical importance of documented changes in histology over time. Two-hundred and five of these patients had an initial diagnosis of nodular lymphoma and were reviewed for this analysis. Sixty-three underwent a repeat biopsy greater than 6 mo after initial diagnosis. In 23 patients, these repeat biopsies revealed a change in histology to a diffuse pattern and/or a change to a larger 'histiocytic' cell type, while repeat biopsies for the other 40 (63%) disclosed persistence of a nodular pattern and no clear change in basic cell type. Progression from nodular lymphoma to diffuse histiocytic, mixed, or undifferentiated types of lymphomas of Rappaport was found in repeat biopsies obtained from 19 patients (30%). Prognosis for survival following a biopsy that demonstrated histologic change was related to the histology demonstrated at the most recent biopsy and to the response to subsequent drug treatment. Survival following repeat biopsy for these 19 patients was significantly shorter than for the 40 patients whose histology remained nodular (p<0.001). However, attainment of a complete remission with intensive combination chemotherapy was associated with prolonged survival in eight patients and prolonged disease-free survival in one patient. Since prior treatment may compromise the ability to achieve a complete response to chemotherapy in patients with nodular lymphoma who develop an aggressive diffuse histology, the likelihood of histologic progression must be considered in the design of future clinical trials in nodular lymphoma. Histologic progression, while associated with a worsened prognosis, does not preclude attainment of a complete response to intensive chemotherapy.