Outcomes among high-risk and standard-risk multiple myeloma patients treated with high-dose chemotherapy and autologous hematopoietic stem-cell transplantation

Background Conventional cytogenetics and interphase fluorescence in-situ hybridization (FISH) identify a high-risk multiple myeloma population characterized by poor response and short survival. Patients and Methods We compared outcomes between high-risk and standard-risk myeloma patients who underwent autologous hematopoietic stem-cell transplantation (auto-HCT) at our institution between January 2005 and December 2009. High-risk myeloma was defined as -13/del(13q) or hypodiploidy in at least 2 metaphases of conventional cytogenetics, or -17/del(17p), t(4;14), t(14;16), t(14;20), hypodiploidy (< 45 chromosomes excluding -Y), or chromosome 1 abnormalities (+1q, -1p, t(1;x)) on FISH or conventional cytogenetics. Results Of 670 myeloma patients, 74 (11%) had high-risk myeloma. These high-risk patients had significantly lower overall response rates (74% vs. 85%; P <.01), shorter median progression-free survival (10.3 vs. 32.4 months; P <.001), and shorter overall survival (28 months vs. not reached; P <.001) than the standard-risk patients. Having only 1 high-risk cytogenetic abnormality or experiencing at least very good partial remission after auto-HCT independently predicted improved progression-free survival and overall survival (P <.05) in high-risk patients. Conclusion Even in an era of novel therapies, cytogenetically identified high-risk myeloma patients have worse prognoses than standard-risk myeloma patients after auto-HCT, and having more than 1 high-risk cytogenetic abnormality further reduces survival.