Evaluation of minimal residual disease by interphase FISH in multiple myeloma: does complete remission exist?

As in other hematological malignancies, the achievement of a complete remission (CR) is important in multiple myeloma but is still based on common cytological and electrophoretic criteria. In this report, we studied 14 patients who achieved an apparent CR following high-dose therapy using fluorescence in situ hybridization (FISH) analysis. Although the results were difficult to interpret in two patients, 12 of 14 patients had unequivocal persistence of abnormal plasma cells in their bone marrow. Our results suggest that only a few patients, if any, are in true CR following one course of high-dose therapy and are in favor of post-transplantation treatments.