Loss of chromosome 9p21 and decreased p16 expression correlate with malignant gastrointestinal stromal tumor

Table 4 Rresults of loss of heterozygosity in 51 gastrointestinal stromal tumors according to Fletcher’s classification

Risk classification	1751			1846			9421			1748
	LOH (n)	Hetero-zygosity (n)	Rate (%)	LOH (n)	Hetero-zygosity (n)	Rate (%)	LOH (n)	Hetero-zygosity (n)	Rate (%)	LOH (n)	Hetero-zygosity (n)	Rate (%)
Very low and low	2	7	22.2	3	6	33.3	3	9	25.0	1	9	10.0
Intermediate	2	5	28.6	4	7	36.4	4	8	33.3	2	8	20.0
High	6	5	54.5	5	7	41.7	9	5	64.3	5	8	38.5

¹There was a higher loss of heterozygosity (LOH) frequency of D9S942 in the high-risk than in non-high-risk tumors (P < 0.05, χ² = 4.47). There were no substantial differences in LOH frequencies among three groups of 4 markers.