Deletion of the short arm of chromosome 1 (del 1p) is a strong predictor of poor outcome in myeloma patients undergoing an autotransplant.

Several chromosomal abnormalities detected by conventional cytogenetic analysis have an adverse impact on the outcome in myeloma patients. A wide spectrum of abnormalities involving chromosomes 1, 13, 14, and 17 has been described. We analyzed the outcome of 83 patients with clonal cytogenetic abnormalities, who underwent high-dose therapy and autologous stem cell transplantation for multiple myeloma at our institution. Clonal abnormalities were detected at diagnosis by conventional cytogenetic analysis in 83 patients. Patients underwent a single autologous transplant between April 2000 and May 2005. Preparative regimen was high-dose melphalan alone (73), or a combination of topotecan, melphalan, and cyclophosphamide (TMC=10). The most commonly observed chromosomal abnormalities were deletion of chromosome 13 (32%), hyperdiploidy (21%), deletion of chromosome 1p (18%), and t (11; 14) in 7% patients. Median follow-up among surviving patients was 25.5 months. Median interval from diagnosis to autotransplant was 7.7 months (range: 2.5-52). Median progression-free survival (PFS) for the entire group was 19 months and the median overall survival (OS) was 52 months. On univariate analysis, both PFS and OS were significantly shorter in patients with deletion 1p (P=.001 and <.0001, respectively). Thirty-two patients whose cytogenetic abnormalities returned to normal prior to autotransplant had longer PFS and OS than patients with persistent abnormalities (P=.02 and .08, respectively). Deletion 1p is associated with a significantly shorter remission and survival in patients undergoing high-dose therapy and a single autologous transplant for myeloma.