Bcl-2 protein expression is not related to short survival in multiple myeloma

The oncoprotein bcl-2 can be expressed in malignant plasma cells and might play a role in the prevention of corticosteroid-mediated apoptosis, thereby prolonging survival of the myeloma cells. We retrospectively investigated whether bcl-2 expression in bone marrow plasma cells measured by two-color fluorescence for immunoglobulin light chains would be related to survival duration in patients suffering from multiple myeloma. In all patients the large majority of plasma cells expressed bcl-2 (median 91%, range 74-100%). Contrary to our expectations, a tendency was observed toward higher percentages bcl-2+ plasma cells in patients with a long survival (more than 5 years, n = 9) vs patients who died from refractory myeloma within a year of diagnosis (n = 7). This tendency was found even when analysis was extended to include four patients in the short diagnosis group (n = 11) who had received chemotherapy prior to bone marrow examination.