HYPERDIPLOID MYELOMA CELL AS AN INDICATOR OF POOR-PROGNOSIS AND DRUG REFRACTORINESS

Although almost 40% of patients with multiple myeloma respond to initi al chemotherapy, myeloma with no response to initial chemotherapy rema ins a serious problem. To understand the characteristics of drug-refra ctoriness of myeloma, fresh tumor cells from 13 untreated myeloma pati ents were fixed and stained with anti-human immunoglobulins and propid ium iodide for subsequent flow cytometric analysis of DNA content. Mor e than 10% of myeloma cells were hyperdiploid in eight cases (hyperdip loid + cases) while less than 10% of myeloma cells were hyperdiploid i n five cases (hyperdiploid - cases). The proportion of hyperdiploid ce lls among all myeloma cells was highly correlated with incidence of my eloma cells with morphologically abnormal nuclei such as those with mu ltiple-nuclei or convoluted nuclei (P = 0.001). Among the eight hyperd iploid + cases, two (2/8) showed good response to subsequent chemother apy while four of five hyperdiploid - cases (4/5) responded well. Case s with poor response had more hyperdiploid myeloma cells (average 25.7 % of all myeloma cells) than sensitive cases (average 6.8%), suggestin g a contribution of hyperdiploid myeloma cells to primary drug resista nce (P = 0.065). The 3 year survival rate of hyperdiploid + cases was 0% while that of the control group was 41.9%. These results suggest th at myeloma cells with abnormal nuclear morphology may show hyperdiploi dy and poor response to chemotherapy. (C) 1997 Elsevier Science Irelan d Ltd.