Paired sample analysis identifies 3 patterns of clonal evolution. (A) Heat map showing CNAs in the 24 patients with sample pairs analyzed on the Agilent 244k exclusively (4 samples analyzed on Agilent 44k or mixture of 44k and 244k are not shown). The first 2 sequential samples for each patient are stacked, with the first sample shown on the top. Sample pairs are indicated on the y-axis and chromosome location on the x-axis. Blue shading indicates the presence of copy number loss, red indicates copy number gain, and white indicates regions with no CNA. Black, blue, and red bars indicate groups of patients with no copy number changes, with only acquired new changes, or with both losses and gains of CNA over time, respectively. The latter 2 groups are ordered from top to bottom from the least to the most changes. (B) Summarized findings from the 28 patients with a sequential sample pair. Colored bars represent theoretical CNAs perceived to exist at a particular point in the evolution of the tumor. (C) Bar graph showing the relation between copy number changes and standard (n = 18) and high (n = 8) cytogenetic risk status. Samples are ordered left to right, based on the total number of changes. The number of losses and acquired events are shown independently. There is a significant difference in the total number of changes detected between the standard and high-risk cytogenetic groups (P < .02) with a higher number of changes found in the high-risk group.