ABSTRACT
<p><b>OBJECTIVE</b>To study the loss of heterozygosity (LOH) on chromosome 3p in thyroid tumors.</p><p><b>METHODS</b>LOH at 11 microsatellite loci was analyzed in 74 cases of thyroid tumors (including 20 follicular adenomas, 24 follicular thyroid carcinomas and 30 papillary thyroid carcinomas) by polymerase chain reaction and silver stain.</p><p><b>RESULTS</b>LOH on chromosome 3p was detected in 71% of follicular thyroid carcinoma (17/24), 30% of the papillary thyroid carcinoma (9/30) and 10% of the follicular adenoma (2/20) case. Two minimal common deleted regions (CDR) (3p26-pter and 3p14.2-3p22) involving significant sites of LOH has identified in follicular thyroid carcinoma. There was also one CDR (3p25. 2-26.1) in papillary thyroid carcinoma.</p><p><b>CONCLUSIONS</b>LOH is more frequently identified in follicular thyroid carcinoma than in papillary thyroid carcinoma and follicular adenoma. The 3 CDR on chromosome 3p may harbor tumor suppressor genes involved in the pathogenesis of follicular thyroid carcinoma and papillary thyroid carcinoma.</p>