Cytogenetic studies of breast carcinomas: Different karyotypic profiles detected by direct harvesting and short‐term culture

Abstract

Chromosome analysis was performed on samples from 85 consecutive patients with breast cancer by one or more of three different methods: direct harvest, culture after mechanical disaggregation, and culture after collagenase digestion. Metaphases suitable for karyotyping were obtained in 70% of the cases; direct harvest yielded metaphases in 29% and cultures without and with digestion in 40% and 59%, respectively. Chromosomal abnormalities were detected in 37 cases. Cells judged to be phenotypically abnormal in culture were twice as likely to reveal chromosomal aberrations as normal-looking cells. Eight cases showed multiclonal abnormalities. Significant differences were detected in the karyotypic profile depending on the method used. With direct harvest, the yield of complex chromosomal changes was 87%, compared to 44% after culture of digested tissue (P < 0.01), and also polyploidy was more common in direct-harvested samples. Detailed karyotypic analysis was possible in 29 primary tumors. The chromosomes most frequently involved were 1, 3, 7, 11, 16, and 17. Recurrent structural abnormalities were der(1;16)(q10;p10), i(1)(q10), del(6)(q21), and del(1)(p22). Breakpoints clustered to the centromere regions of chromosomes 1, 3, 11, 15, and 16 and to the short arms of chromosomes 7, 17, and 19. Seven of twenty-nine fully analyzed cases had a family history of breast cancer, and changes of chromosomes 1, 3, and 15 seemed to be more common in these cases. There was an association between karyotype and survival: The 3 year survival was 63% in patients with complex karyotypic changes and 92% in those without complex changes.

Chromosome 2 (2p16) abnormalities in Carney complex tumours

“…[32][33][34] Amplification of the region represented by HSRs occurred in 60% of the samples, deletions in 32%, and amplification and deletion of 2p16 in different cell populations from the same lesion in the remaining 8%. These data are consistent with the CGH data and our previous findings of inconsistent microsatellite alterations of the 2p16 region.…”

TP53 Abnormalities and Genetic Instability in Breast Cancer

“…2). Clonal abnormalities, both numerical and structural, were detected in 65% of cases that were successfully analysed (9). Clonal chromosomal changes were found in samples with and without TP53 abnormalities,…”

“…Tissue samples were digested with collagenase and cultured in a special serum-free medium at 37°C for 3-6 days (8). The cells were arrested in mitosis by colchicine treatment and chromosomes harvested by standard methods (7,9). In addition a small fraction of tissue was used for direct harvesting of chromosomes.…”

“…Single structural changes or up to four numerical alterations were defined as simple changes. All other aberrations were called complex (7,9).…”

Preferential Occurrence of Breast Carcinomas with Loss of Chromosome 16q and der(16)t(1;16)/der(1;16) in Middle‐aged Patients with Hyperplasia of Mammary Glands

“…6) Most of the 1;16 fusion was found at or near α-or β-satellite repetitive sequences on both fragments of chromosomes 16 and 1. [7][8][9] Because these repetitive sequences are a hot spot of DNA recombination, the loss of 16q with or without the 1;16 fusion is suggested to occur by heterologous chromosome pairing and subsequent DNA recombination. 10,11) In the previous study, der (16)t(1;16) formation was detected more frequently in the breast cancers occurring in younger patients.…”