Disclosed herein are chromosomal loci associated with clinical outcome to treatment for multiple myeloma. Genome-wide changes observed in myeloma relate to prognosis and treatment response to a proteasome inhibitor. Compositions and methods are provided to assess DNA copy number at corresponding to markers of loci and genes found thereon which are amplified or deleted, overexpressed or underexpressed in myeloma tumors to predict response to treatment, time-to-progression and survival upon treatment.