Correlation of allelic losses and clinicopathological factors in primary breast cancers

Human breast cancers frequently show allelic loss or loss of heterozygosity (LOH) at specific chromosomal regions. To understand the possible role of these genetic alterations in tumor development and progression, we examined LOH at loci on chromosomal arms lp, 3p, 11p, 13q, 16q, 18q, and 22q in 140 to 246 cases of primary breast cancers and compared it with lymph node metastasis, histological type, tumor stage, estrogen receptor (ER) and progesterone receptor (PgR) status. LOH at 1p22-31 correlated with lymph node metastasis and a tumor size of greater than 2 cm. LOH at 13ql2-14 and 18q21 were most frequently observed in tumors of the solid-tubular type. LOH at 1p34-36 was more frequent in tumors of the scirrhous and solidtubular types than in other less aggressive histological types. Furthermore, a significant association was observed between LOH at 3pl4-21, 11p11-15 and 13ql2-14 and the absence of progesterone receptors. These results suggest that some clinical characteristics of breast cancers are determined by loss of tumor suppressor genes present at specific chromosomal regions.