Spectral karyotyping and chromosome banding studies of primary breast carcinomas and their lymph node metastases

Three primary breast tumors and their lymph node metastases were characteri zed by G-banding, spectral karyotyping (SKY), and fluorescence in situ hybr idization (FISH). In each case, the karyotypic abnormalities detected were similar in the primary tumor and its matched metastasis. Two of the pairs h ad near-diploid karyotypes with three to four chromosomal aberrations, wher eas the third pair had a near-pentaploid chromosome content and many marker chromosomes in the primary tumor and a near-tetraploid chromosome number w ith almost the same marker chromosomes in the metastasis. SKY and FISH conf irmed the karyotypic similarities between the primary tumors and their meta stases and, in addition, improved the identification and characterization o f marker chromosomes. One of the tumor pairs with near-diploid karyotypes h ad gain of 8q, 16q, and 17q, whereas the other had gain of 1q and chromosom e 8 material in the form of ring chromosomes. The third pair had more compl ex chromosomal translocations and numerical changes resulting in net gain o f material from chromosomes X, 1, 2, 6, 7, 14, 16, 19, and 20, and chromoso me arms 8q and 1 Iq, as well as net loss of material from chromosomes 3, 13 , 18, 21, and 22. The present study underscores the need to combine convent ional chromosome banding and molecular cytogenetic techniques in the cytoge netic analysis of solid tumors.