Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study

Comparative cytogenetic and DNA flow cytometric analysis of 242 primary breast carcinomas

The cytogenetic and DNA flow cytometric findings in 242 breast carcinomas were compared. The combined use of both techniques improved the detection of abnormal cell populations from 65% by cytogenetic analysis alone and 59% by DNA flow cytometric analysis alone to 84%. Informative and comparable cytogenetic and flow cytometric data were obtained for 155 tumors. Among these 155 tumors, there was good concordance (64%) between the estimates of genomic changes by the two methods. Most discrepancies were among the DNA-diploid cases, where cytogenetic analysis detected small genomic changes. There were, however, also some exceptions in which large genomic changes detected by one method were missed by the other. Of the specific breast cancer-associated cytogenetic aberrations subjected to separate correlation analysis, polysomy for chromosome 20 was significantly associated with a high S-phase fraction, whereas loss of the long arm of chromosome 16 and/or the presence of a der(1;16) were significantly associated with a low S-phase fraction. Our data show that cytogenetic and DNA flow cytometric analyses of breast carcinomas give largely comparable results, and that combining data from both methods significantly improves the information obtained by either technique used alone on the genetic abnormalities in these tumors.

Cytogenetics of epithelial hyperplasias of the human breast

Generally, benign breast lesions behave like innocuous and limited proliferations; however, sometimes they can represent precancerous pathologies. The cytogenetic analysis of five mammary epithelial hyperplasias is reported. Four cases had clonal chromosome alterations. All of the cases presented a modal number of 46 chromosomes. Chromosome 9 monosomies and chromosome 1 deletions were common in these benign tumors. The study of benign proliferations of the breast may reveal a possible relationship between chromosomal alterations and the conditions of the tissue.

Detection of genetic alterations in micrometastatic cells in bone marrow of cancer patients by fluorescence in situ hybridization

Detection of micrometastatic tumor cells in bone marrow of cancer patients has been shown to be of prognostic significance. To further characterize these cells, we combined antibody labeling and fluorescence in situ hybridization (FISH). For detection of numerical changes of chromosome 17, nine patients with proven breast cancer whose bone marrow contained epithelial tumor cells were evaluated. Epithelial cells were stained by anticytokeratin antibody. Afterwards FISH was performed using an alpha-satellite probe specific for chromosome 17. In a second series bone marrow epithelial cells of eight patients with breast cancer and of six with prostatic cancer were evaluated for the amplification of HER-2/neu by using a gene-specific DNA probe. In the first series four patients had only single epithelial cells in their bone marrow. Only one single cell showed five hybridization signals, whereas all other single cells showed two or less. Five patients had clusters of epithelial cells in bone marrow with or without additional single cells. One hundred four cells had three or more hybridization signals and 103 of these polysomic cells were located in tumor cell clusters. In the second series we could detect HER-2/neu amplification in bone marrow epithelial tumor cells in two of eight patients with breast cancer but in none of the prostatic cancer patients. These results show that it is possible to detect numerical chromosomal changes and oncogene amplification in bone marrow micrometastatic epithelial cells of cancer patients by combining immunophenotyping and FISH.

Correlation of numerical chromosome 11 and 17 imbalance with metastasis of primary breast cancer to lymph nodes

Abnormalities of chromosomes 11 and 17 have been widely reported in invasive carcinoma of the breast. Interphase cytogenetics using pericentromeric repeat probes allows the evaluation of numerical chromosomal aberrations in tumour cell populations. We have developed a method for interphase cytogenetics on fine needle aspirates taken from breast tumours and have applied it to the analysis of chromosomes 11 and 17 in 49 cases of invasive adenocarcinoma. Frequency distributions of signal number were generated for each case and no correlation was found between modal signal number and tumour size at presentation, nodal status or tumour differentiation. In 14 cases, two copies of each of chromosomes 11 and 17 were present, and in 14, the number of chromosomes 11 and 17 were equal but abnormal. In 14 cases, the chromosome 11 number was greater than chromosome 17 and in 7 cases, the chromosome 17 number was greater than chromosome 11. Chromosome inequality correlated with the presence of lymph node metastases or disseminated disease at presentation and the absence of in situ carcinoma. There was no relationship with the presence of vascular invasion. These data suggest that numerical chromosome 11 and 17 imbalance may indicate the ability of breast cancers to metastasize rather than invade vessels. The pattern of numerical chromosome abnormality described may define a subgroup of tumours with a greater tendency for metastasis.