Biologic and clinical advances in multiple myeloma.

Recent advances in our understanding of the cellular and molecular derangements involved in multiple myeloma are beginning to be translated into novel therapeutic approaches. Growth factors, specifically interleukin-6, appear to be critical for disease progression, and interruption of autocrine and paracrine loops has been achieved, with resultant inhibition of myeloma cell growth. Oncogenes, tumor-suppressor genes, and cell-survival genes have all been found to be dysregulated in some myeloma patients. The implications of acquisition of the multidrug resistance phenotype are just beginning to be understood. High-dose therapeutic regimens with bone marrow or peripheral stem-cell rescue are being studied in an attempt to produce a cure. Autologous marrow and peripheral blood stem-cell transplantation are better suited to the older myeloma patient population than is allogeneic marrow transplantation, and have also yielded promising results.