Correlation of DNA hypomethylation at pericentromeric heterochromatin regions of chromosomes 16 and 1 with histological features and chromosomal abnormalities of human breast carcinomas.

Changes in DNA methylation status are not only important for regulating gene expression but are also suggested to induce chromosome instability. To reveal the correlation of DNA methylation status in heterochromatin regions with tumor histology and with chromosome alterations, DNA methylation status was examined by Southern blot analysis, and numerical and structural chromosome alterations, including the formation of der(16)t(1;16)/der(1;16), were examined by fluorescence in situ hybridization at the two loci in the pericentromeric satellite 2 regions of chromosomes 16 and 1 in 39 human breast carcinomas. DNA hypomethylation at the D16Z3 and the D1Z1 loci was detected in 31% (12 of 39) and 36% (12 of 33) of carcinomas, respectively, and mostly concurred.

Allelotype analysis of common epithelial ovarian cancers with special reference to comparison between clear cell adenocarcinoma with other histological types.

Determination of the histological type of epithelial ovarian cancer is clinically important to predict patient prognosis. To estimate accurately the chromosomal regions that frequently show loss of heterozygosity (LOH) in each histological type, LOH at 55 loci on 38 chromosomal arms was examined by means of laser capture microdissection and PCR-LOH analysis in 45 epithelial ovarian cancers composed of clear cell adenocarcinoma (CCA), serous adenocarcinoma (SEA), endometrioid adenocarcinoma (EMA) and mucinous adenocarcinoma (MUA). In addition, p53 (exons 5 - 8) gene mutations and the nuclear immunoreactivity of p53 proteins in these tumors were examined by PCR-SSCP and immunohistochemistry.

Different pattern of loss of heterozygosity among endocervical-type adenocarcinoma, endometrioid-type adenocarcinoma and adenoma malignum of the uterine cervix.

It is unclear which chromosome arms frequently show loss of heterozygosity (LOH) in adenocarcinoma of the uterine cervix. To identify such chromosomal arms, LOH on 52 different chromosome loci was examined using laser capture microdissection and PCR-LOH analysis in 25 common-type adenocarcinomas, comprising 13 cases of endocervical type, 12 cases of endometrioid type and 7 cases of adenoma malignum without the component of conventional endocervical-type adenocarcinoma (designated as "pure" form). In adenocarcinomas of endocervical type and endometrioid type, LOH was commonly detected on chromosome arms 17p (62% and 50%, respectively), 1p (33% and 67%) and 22q (40% and 33%).

Detection of numerical alterations of chromosome 1 in cytopathological specimens of breast tumors by chromogen in situ hybridization.

To investigate the effectiveness of chromogen in situ hybridization (CISH) in the diagnosis of breast tumors, numerical alterations of chromosome 1 were examined by CISH and fluorescence in situ hybridization (FISH) methods, and the presence of der(16)t(1;16) was also examined by FISH in imprinted cytology specimens from resected tissues of 14 carcinomas and five non-malignant lesions. The modal signal counts of chromosome 1 were compared between the specimens processed by CISH and FISH for each case. Aneusomies of the long arm of chromosome 1 were detected in 10 (71%) carcinomas as the major clones by both methods.

Pattern of chromosome 16q loss differs between an atypical proliferative lesion and an intraductal or invasive ductal carcinoma occurring subsequently in the same area of the breast.

Atypical proliferative lesions of the breast, such as atypical ductal hyperplasia and atypical papilloma, are considered to be precursors of breast carcinomas and have frequently been shown to have loss of heterozygosity (LOH) on chromosome 16q at the DNA level. We evaluated whether an atypical proliferative lesion and a carcinoma that subsequently occurred in the same area of the ipsilateral breast were of identical clonal origin in seven patients. Using DNA isolated from microdissected archival tissue of epithelial components of both the biopsy specimen of the atypical proliferative lesion and the mastectomy specimen of the carcinoma, the pattern of LOH on 16q was compared between these two lesions using polymerase chain reaction -microsatellite LOH analysis.

Detection of Numerical Alterations of Chromosomes 3, 7, 17 and X in Low-grade Intracystic Papillary Tumors of the Breast by Multi-color Fluorescence In Situ Hybridization.

Intracystic papillary tumors of the breast comprise intraductal papillomas and low-grade papillary carcinomas. To determine chromosomal alterations that may be characteristic of these tumors, chromosomes 3, 7, 17 and X were examined in 10 intraductal papillomas and 14 low-grade papillary carcinomas using multicolor fluorescent in situ hybridization. In papillry carcinomas, numerical/structural alterations in chromosome 17 and the accumulation of numerical alterations in chromosomes 3, 7 and X were detected in 21%(3/14) and 15%(2/13) of the cases, respectively.

Evaluation of histopathological criteria for identifying node-negative breast cancer with high risk of early recurrence in the NSAS-BC protocol study.

Background: The histopathological criteria for high-risk node-negative primary breast cancer stated in the National Surgical Adjuvant Study of Breast Cancer (NSAS-BC) protocol were used to grade a consecutive series of 488 cases at our hospital.

Methods: To validate the criteria retrospectively, we examined the histological features of node-negative primary breast cancers which showed early relapse within 2 years after surgical therapy.

Results: Early relapse occurred in 12 patients, distant metastases in 11, and local recurrence in one.

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.

Structural and numerical alterations of chromosome 16 are considered to be commonly involved in the genesis of breast cancer. To reveal etiological factors that predispose cells to these alterations, we examined the frequencies of chromosome 16 aneusomy, 16q loss and 1;16 fusion indicating der (16) t (1;16) / der (1;16) by multi-color fluorescence in situ hybridization in 46 tumors resected mostly from young ( /= 75 years old) women, and compared the results with those in a patient group representing a common age distribution of Japanese patients in whom chromosome 16 status in the tumor had already been studied. The correlation of these chromosome 16 alterations with age, hyperplasia in adjacent mammary glands, cancer history, and obesity indices was investigated in a total of 244 patients.

Large, central acellular zones indicating myoepithelial tumor differentiation in high-grade invasive ductal carcinomas as markers of predisposition to lung and brain metastases.

High-grade invasive ductal carcinomas (IDCs) of the breast with large, central acellular zones on their cut surfaces are usually associated with the myoepithelial immunophenotype of carcinoma cells, which includes the expression of S-100 protein, alpha-smooth muscle actin, and keratin 14. To clarify the clinical significance of these features of IDCs, the authors compared the incidence of the myoepithelial immunophenotype immunohistochemically, patient prognosis, and metastatic sites of the tumor between 20 high-grade IDCs with large, central acellular zones and 40 control high-grade IDCs without these zones. The myoepithelial immunophenotype was detected in 16 IDCs (80%) with large, central acellular zones but in only seven IDCs (18%) without.

Myoepithelial differentiation in high-grade invasive ductal carcinomas with large central acellular zones.

We hypothesized that invasive ductal carcinomas (IDCs) with large central acellular zones comprising necrosis, tissue infarction, collagen, and hyaline material on their cut surfaces are formed in association with myoepithelial differentiation of the carcinoma cells. To verify this, the expression of S100 protein, alpha-smooth muscle actin (alpha-SMA), and glial fibrillary acidic protein (GFAP) and keratin 14, which has been shown to represent the myoepithelial immunophenotype, was examined immunohistochemically in 18 IDCs with such central zones covering more than 30% of each tumor area, 18 IDCs without such areas as negative controls, and 10 metaplastic carcinomas as positive controls for myoepithelial differentiation. Expression of S100, detected with a polyclonal antibody, S100-alpha, S100-beta, alpha-SMA, GFAP, and keratin 14, was observed in 61%, 83%, 39%, 33%, 28%, and 39% of the IDCs with large central acellular zones, 17%, 44%, 6%, 6%, 0%, and 6% of the IDCs without such zones, and 80%, 70%, 50%, 100%, 80%, and 50% of the metaplastic carcinomas, respectively.

Correlation of numerical and structural status of chromosome 16 with histological type and grade of non-invasive and invasive breast carcinomas.

Loss of heterozygosity on chromosome arm 16q frequently occurs in human breast carcinomas regardless of the histological grade or type. To reveal whether the status of chromosome 16 corresponds to the histology of breast carcinomas, we examined the signal number of 16cen, 16q breakpoints and 1;16 fusions in the interphase nuclei of 185 breast carcinomas using fluorescence in situ hybridization to detect the loci D16Z2 (16cen), D16Z3 (16q11), D16S154 (16q24) and D1Z1 (1q12). A 16q loss associated with a proximal or distal breakage was identified as a discrepancy between the modal signal counts of the D16Z2, D16Z3 and D16S154 loci in each tumor.

der(16)t(1;16)/der(1;16) in breast cancer detected by fluorescence in situ hybridization is an indicator of better patient prognosis.

By two-color fluorescence in situ hybridization (FISH), der(16)t(1;16) or der(1;16) was frequently detected in low-grade papillary carcinoma but not in benign intraductal papilloma of the breast. In order to clarify the incidence and clinicopathological significance of der(16)t(1;16)/der(1;16) in common breast cancers, der(16)t(1;16)/der(1;16) was examined by two-color FISH in breast cancers resected from 51 patients by using DNA probes for 16cen, 16q11.2, and 1q12 labeled with biotin or digoxigenin.

Detection of alterations in chromosomes 16 and 1 by fluorescence in situ hybridization in breast tumors cytologically or histologically equivocal for malignancy.

Structural and numerical alterations, and fusion of chromosomes 16 and 1 have been shown to occur frequently in low-grade breast carcinoma, but not in benign papilloma by fluorescence in situ hybridization (FISH). We carried out FISH analysis of 11 benign tumors and 3 breast tumors for which the preoperative diagnosis was equivocal for cancer. In 11 benign lesions and 1 benign phyllode tumor which was cytologically equivocal for malignancy, alteration of the chromosome 16 or 1 signal was not detected as a predominant cell clone.

Detection of numerical and structural alterations and fusion of chromosomes 16 and 1 in low-grade papillary breast carcinoma by fluorescence in situ hybridization.

Intracystic papillary breast tumors, including intraductal papilloma and low-grade intracystic papillary carcinoma, constitute a group for which differential diagnosis is frequently difficult. We examined the status of chromosomes 16 and 1 by multicolor fluorescence in situ hybridization (FISH) analyses and the DNA ploidy patterns by flow cytometry in 26 intracystic papillary tumors. Alterations of chromosomes 16 and 1 were detected by FISH in 93 and 85%, respectively, of 14 low-grade papillary carcinomas, and the latter alterations always concurred with the former.