Figure 2

Heterogeneity for LOH on chromosome 18p in breast cancer progression. Schematic diagrams show the different patterns of progression based on this chromosome 18p study. Nine cases show clonal progression where 18p LOH occurs either in DCIS or IDC and is clonally inherited in related later stages of tumor progression. Two cases show LOH first appearing in the metastatic stage. In contrast, four cases show heterogeneity for alterations on 18p. Two specimens show LOH in the DCIS component but not in the associated IDC component. The other cases show the presence of microsatellite instability in earlier but not later stage disease.