Table 4.

Prevalence of clonal heterogeneity in premalignant tissue

Clonal heterogeneity	No. of patients* (%)
Single clone	14 (32)
Ploidy change, same LOH pattern†	13 (30)
Mutually exclusive clones‡	4 (9)
Alternate alleles lost§	7 (16)
Change in LOH pattern, accumulation of loss∥	13 (30)

^*Some patients had loss of heterozygosity (LOH) patterns in multiple categories. Percent is calculated from 44 total patients.

^†Patients with the same alleles and loci lost on each chromosome in all samples with LOH.

^‡Patients have both 9p LOH and 17p LOH but never both in the same samples.

^§Patients with one clone that has loss of the smaller allele and a second clone that has loss of the larger allele.

^∥Patients have clones with different LOH patterns along the chromosome or clones that have evolved to contain LOH on both 9p and 17p chromosomes.