TRISOMY-8 AND TRISOMY-18 AS FREQUENT CLONAL AND SINGLE-CELL ABERRATIONS IN 185 PRIMARY BREAST CARCINOMAS

For cytogenetic investigations short-term cultures of 185 breast carci nomas (135 invasive ductal, 21 invasive lobular, 12 invasive ductal wi th intraductal components, seven heterogeneous, six intraductal, four invasive ductal and lobular) were prepared. Cytogenetic examinations r evealed clonal abnormalities in 39 cases with a predominance of simple numerical chromosome changes, i.e., trisomies of chromosomes 7, 8, an d 18. One hundred forty-six tumors did not show clonal abnormalities, but single-cell aberrations other than monosomies occurred in 79 of th ese tumors. Compared to cells of epithelial hyperplasia of the breast, amniotic fluid cells, and cells from pleomorphic adenomas cultivated using the same medium, the frequency of single-cell trisomies was sign ificantly higher. Trisomy 8 was not only found as a clonal aberration in 10 cases but was also the most frequent non-clonal aberration. Tris omy 7 and 18 were also frequent clonal as well as non-clonal cytogenet ic deviations.