Growth arrest-specific gene 6 expression in human breast cancer

Growth arrest-specific gene 6 (Gas6), identified in 1995, acts as the ligand to the Axl/Tyro3 family of tyrosine kinase receptors and exerts mitogenic activity when bound to these receptors. Overexpression of the Axl/Tyro3 receptor family has been found in breast, ovarian and lung tumours. Gas6 is upregulated 23-fold by progesterone acting through the progesterone receptor B (PRB). Recently, Gas6 has been shown to be a target for overexpression and amplification in breast cancer. Quantitative real-time PCR analysis was used to determine the levels of Gas6 mRNA expression in 49 primary breast carcinomas. Expression of PRB protein was evaluated immunohistochemically with a commercially available PRB antibody. The results showed a positive association between PRB protein and Gas6 mRNA levels (P=0.04). Gas6 correlated positively with a number of favourable prognostic variables including lymph node negativity (P=0.0002), younger age at diagnosis (P=0.04), smaller size of tumours (P=0.02), low Nottingham prognostic index scores (P=0.03) and low nuclear morphology (P=0.03). This study verifies for the first time the association between PRB and Gas6 in breast cancer tissue.

Formalin-fixed paraffin-embedded clinical tissues show spurious copy number changes in array-CGH profiles

Formalin-fixed paraffin-embedded (FFPE) archival clinical specimens are invaluable in discovery of prognostic and therapeutic targets for diseases such as cancer. However, the suitability of FFPE-derived genetic material for array-based comparative genomic hybridization (array-CGH) studies is underexplored. In this study, genetic profiles of matched FFPE and fresh-frozen specimens were examined to investigate DNA integrity differences between these sample types and determine the impact this may have on genetic profiles. Genomic DNA was extracted from three patient-matched FFPE and fresh-frozen clinical tissue samples. T47D breast cancer control cells were also grown in culture and processed to yield a fresh T47D sample, a fresh-frozen T47D sample and a FFPE T47D sample. DNA was extracted from all the samples; array-CGH conducted and genetic profiles of matched samples were then compared. A loss of high molecular weight DNA was observed in the FFPE clinical tissues and FFPE T47D samples. A dramatic increase in absolute number of genetic alterations was observed in all FFPE tissues relative to matched fresh-frozen counterparts. In future, alternative fixation and tissue-processing procedures, and/or new DNA extraction and CGH profiling protocols, may be implemented, enabling identification of changes involved in disease progression using stored clinical specimens.

Gain of imprinting of SLC22A18 sense and antisense transcripts in human breast cancer

The 11p15.5 region harbors three imprinted sense/antisense transcript pairs, SLC22A18/SLC22A18AS, IGF2/IGF2AS (PEG8), and KCNQ1/KCNQ1OT1 (LIT1). SLC22A18 (solute carrier family 22 (organic cation transporter) member 18) and its antisense transcript SLC22A18AS are paternally suppressed in fetal samples. In adult tissue, SLC22A18 displays polymorphic imprinting, but the imprinting status of SLC22A18AS remains elusive. SLC22AI8 DNA-PCR-RFLP analysis using NlaIII restriction digestion identified SLC22A18 heterozygotes within this breast tissue cohort (n = 89). Commercial sequencing identified informative SLC22A18AS samples. Random hexamer-primed cDNA synthesis, SLC22A18/SLC22A18AS-specific PCR, and imprinting evaluation by commercial sequencing demonstrated that SLC22A18AS displays a nonimprinted profile in reduction mastectomies (n = 6). However, SLC22A18 showed a gain of imprinting (GOI) in 1/4 of these normal cases. In the malignant cohort, GOI was also demonstrated in 18% for SLC22A18 and 14% for SLC22A18AS, occurring concomitantly in one case. This study reports the imprinting status of SLC22A18AS in adult tissue, and shows that GOI affects both the sense, and antisense transcripts at this locus in human breast tissue.

Microarray analysis of phosphatase gene expression in human melanoma

BACKGROUND

Tyrosine phosphate is abnormally elevated in malignant melanoma, and this has been interpreted to reflect the activity of oncogenic protein tyrosine kinases. However, elevation may also arise due to decreased protein tyrosine phosphatase (PTP) expression.

OBJECTIVES

To survey phosphatase gene expression in melanoma cell lines, a benign naevus and normal melanocytes: we searched for downregulation of phosphatase gene expression in malignant cells that may indicate a role as melanoma suppressor genes.

METHODS

Microarray analysis was used to compare gene expression for 133 phosphatase genes, comprising 39 PTPs, 16 dual-specificity phosphatases (DSPs), 47 serine/threonine phosphatases and 31 acid/alkaline and lipid-based phosphatases. Northern blotting analysis was used to study gene expression in human melanoma biopsies.

RESULTS

There was decreased expression of four DSP genes (including PTEN); eight receptor PTP genes were downregulated in melanoma, among which were PTP-KAPPA and PTP-PI (consistent with our previous data). In addition, PTP-RF/LAR was downregulated in 13 of 22 metastatic melanomas.

CONCLUSIONS

The expression of multiple PTP receptors is decreased in melanoma; this may be a mechanism which stimulates autonomous growth in advanced melanoma.

High-grade carcinomas of the breast showing patterns of mixed ductal and myoepithelial differentiation (including myoepithelial cell-rich carcinoma of the breast)

AIMS

To assess the clinical, morphological and immunophenotypic characteristics of breast carcinomas showing patterns of mixed epithelial and myoepithelial differentiation.

METHODS AND RESULTS

Included in the study were four carcinomas containing a mixed population of epithelial and myoepithelial cells identified using morphological features at the light microscopic level which were found amongst a review of 500 archival cases and two recently accessioned cases. The carcinomas varied in size from 20 to 38 mm and all were grade 3 ductal carcinomas. Most showed nodular and sheet-like cellular aggregates, although one case showed small solid cell aggregates with duct formation. The cells were large, round, polygonal or spindle-shaped and had areas of clear or eosinophilic cytoplasm in variable proportions. Foci of metaplasic carcinoma were present in three cases. All cases showed strong, patchy positivity for cytokeratin (CK)14, calponin, smooth actin and muscle specific actin. Epithelial membrane antigen and CK8 were positive in a similar proportion of cells. One patient died 23 months following diagnosis with metastatic carcinoma, another patient died of unrelated disease and four patients are alive with follow-up ranging from 18 months to 25 years.

CONCLUSIONS

High-grade carcinomas of the breast showing patterns of mixed ductal and myoepithelial differentiation may show additional morphological features such as foci of metaplasia and appear to have a good prognosis similar to myoepithelial cell-rich carcinomas. However, young age and lymph node metastasis may portend a worse prognosis.

Tyrosine phosphate in melanoma progression

BACKGROUND

Cellular tyrosine phosphorylation is regulated by two large families of enzymes. Protein tyrosine kinases (PTK) mediate addition, and protein tyrosine phosphatases (PTP), removal of phosphate from protein substrates. PTKs are oncogenes and PTPs have been hypothesized to function as tumour suppressor genes.

OBJECTIVES

To determine changes in tyrosine phosphate and PTP activity that occur during melanoma progression.

METHODS

Immunohistochemistry was used to study phosphotyrosine in melanocytic lesions. In addition, PTP activity of normal melanocytes and melanoma cell lines was measured using an enzyme-linked immunosorbent assay-based system.

RESULTS

Melanocytes in normal skin and most (67%) benign naevi were not immunostained. Neither were early malignant lesions (80% of malignant melanoma in situ and radial growth phase melanomas) stained. However, most advanced melanomas (100% of vertical growth phase, and 90% of metastatic melanomas) were immunoreactive. When total PTP enzyme activity was assayed in normal melanocytes and malignant melanoma cell lines, there was a significant increase in activity associated with melanoma progression.

CONCLUSIONS

Taken together, the data suggest increased phosphotyrosine signalling occurs during melanoma progression at the stage when cells first become competent for metastasis.

Elevated expression and altered processing of fibulin-1 protein in human breast cancer

The extracellular matrix protein fibulin-1 suppresses the motility and invasiveness of a variety of tumour cell types in vitro as well as the growth of fibrosarcoma tumours in nude mice. In this study, fibulin-1 protein expression in breast carcinoma specimens and normal breast tissue was evaluated immunohistologically. Fibulin-1 protein expression was also semiquantitatively assessed by immunoblot analysis in a collection of normal breast tissues (n=18), benign tumours (n=5) and breast carcinomas (n=39). In normal breast tissue, fibulin-1 protein expression predominated in the ductal epithelium and underlying myoepithelium, with weaker staining evident in the loose connective surrounding the ducts. Examination of breast carcinomas revealed that the tumour cells also expressed fibulin-1 protein. The level of mature fibulin-1 polypeptide (100 kDa) was higher in the breast carcinoma specimens as compared to normal breast tissue (Mann-Whitney U-test, P=0.0005). In addition to the mature fibulin-1 polypeptide, several smaller sized polypeptides of 55, 50 and 25 kDa were detected using monoclonal antibodies reactive towards an epitope located at the N-terminus of fibulin-1. The immunoreactive 50 kDa polypeptide was detected more frequently in breast carcinoma specimens than in normal breast tissue (chi(2)=17.22, P<0.0001). Furthermore, the ratio of the 50 kDa fragment to the mature fibulin-1 polypeptide correlated with the level of oestrogen receptor alpha (Spearman correlation coefficient, rs=0.49, P<0.003, n=36) and progesterone receptor (rs=0.43, P=0.008, n=36) expression in the tumour specimens. Taken together, these findings indicate that elevated expression and altered processing of fibulin-1 is associated with human breast cancer.

Primary acinic cell carcinoma of the breast

Seven cases of this rare variant of breast carcinoma have been described in three previous publications. This paper describes an additional case, the first following chemotherapy, which in addition had an unfavourable prognosis. It also describes alterations in cell morphology, immunohistochemistry, and ultrastructure following chemotherapy.

Protein tyrosine phosphatase genes downregulated in melanoma

Phospho-tyrosine levels are increased in melanoma, apparently consistent with reports of elevated protein tyrosine kinase activity. Some protein tyrosine kinases are encoded by oncogenes and have been implicated in melanoma genesis. Decreased protein tyrosine phosphatase activity may also increase phospho-tyrosine. Protein tyrosine phosphatase genes are candidate tumor suppressors and loss of expression may contribute to melanoma genesis. Here we survey protein tyrosine phosphatase expression in pigment cells. Protein tyrosine phosphatase genes were cloned by reverse transcriptase polymerase chain reaction using degenerate primers based upon conserved sequences within the phosphatase catalytic domain. Reaction products were cloned and sequenced: 118 and 113 partial protein tyrosine phosphatase products were isolated from normal melanocytes and melanoma cells, respectively. Northern blotting analysis was used to study expression of 15 protein tyrosine phosphatase genes. Expression of PTP-kappa and PTP-pi was absent or downregulated in more than 20% of melanoma cell lines and in some unmanipulated melanoma biopsies. These closely related enzymes are members of the 2B receptor protein tyrosine phosphatase family previously implicated in contact inhibition. Loss of protein tyrosine phosphatase expression may contribute to the abnormal tyrosine phosphorylation seen in melanoma; these genes are candidate tumor suppressors.

Mixed apocrine/endocrine ductal carcinoma in situ of the breast coexistent with lobular carcinoma in situ

An unusual mixed form of ductal carcinoma in situ (DCIS) of the breast is described, which exhibits a biphenotypic morphology encompassing a range of differential diagnostic DCIS subtypes. In addition, immunophenotypic and ultrastructural studies demonstrate neuroendocrine and apocrine differentiation, raising questions regarding appropriate classification and biological behaviour. In two cases, coexistence of this mixed form of DCIS with lobular carcinoma in situ (LCIS) in the same duct lobular units is an additional unusual feature that might, at least in some cases, indicate a closer relation between them.

Frequent loss of imprinting of PEG1/MEST in invasive breast cancer

The human PEG1 gene is a newly identified imprinted gene on 7q32. Genetic aberrations of this chromosomal region are often detected in invasive breast carcinomas. In this study, we show monoallelic PEG1 expression in normal breast tissue, indicating the presence of a functional imprint, and more importantly, we demonstrate loss of imprinting (LOI) in all of seven informative invasive breast carcinomas. In contrast to this, in one case of atypical ductal hyperplasia (ADH) found in residual breast, imprinting was maintained. This raises the possibility that aberrant imprinting of PEG1 may be involved in the progression from hyperplasia to invasive breast cancer.

Loss of heterozygosity of the Wilms' tumor suppressor gene (WT1) in in situ and invasive breast carcinoma

The Wilms' tumor suppressor gene (WT1), a nuclear transcription factor, regulates the expression of the insulin-like growth factor (IGF) and transforming growth factor (TGF) systems, both of which are implicated in breast tumorigenesis. WT1 allelic integrity was examined by loss of heterozygosity (LOH) studies in formalin-fixed, paraffin-embedded (FFPE) ductal carcinoma in situ (DCIS, n = 20) and fresh frozen primary invasive breast carcinomas (n = 24). Loss of heterozygosity (LOH) at the WT1 locus (11p13) was examined by PCR evaluation of an Hinf1 restriction fragment length polymorphism (RFLP) and correlated to tumor stage (in situ and invasive). After identification of the heterozygous/informative breast lesions, 1 of 12 (8.3%) DCIS (high-grade micropapillary) and 3 of 14 (21.4%) of infiltrating carcinomas (high grade) showed loss of one allele, suggesting that LOH of the WT1 locus is a rare genetic event in early breast cancer, becoming more common in invasive and in high-grade lesions.

Widespread chromosomal abnormalities in high-grade ductal carcinoma in situ of the breast. Comparative genomic hybridization study of pure high-grade DCIS

For a variety of technical reasons it is rarely possible to study cytogenetic abnormalities in ductal carcinoma in situ (DCIS) using traditional techniques. However, by combining molecular biology and computerized image analysis it is possible to carry out cytogenetic analyses on formalin-fixed, paraffin-embedded tissue, using comparative genomic hybridization (CGH). The purpose of this study was to identify the prevalence of chromosomal amplifications and deletions in high-grade DCIS and to look specifically for unique or consistent abnormalities in this pre-invasive cancer. Twenty-three cases of asymptomatic, non-palpable, screen-detected, high-grade DCIS were examined using CGH on tumour cells obtained from histology slides. All cases showed chromosomal abnormalities. A wide variety of amplifications and deletions were spread across the genome. The most frequent changes were gains of chromosomes 17 (13 of 23), 16p (13 of 23), and 20q (9 of 23) and amplifications of 11q13 (22 of 23), 12q 24.1-24.2 (12 of 23), 6p21.3 (11 of 23), and 1q31-qter (6 of 23). The most frequent deletions were on 13q 21.3-q33 (7 of 23), 9p21 (4 of 23), and 6q16.1 (4 of 23). These findings indicate that high-grade DCIS is, from a cytogenetic viewpoint, an advanced lesion. There was no absolutely consistent finding in every case, but amplification of 11q13 was found in 22 of the 23 cases. The precise significance of this is unknown at present. This region of chromosome 11q harbours a number of known oncogenes, including cyclin D1 andINT2. It is likely that many of these findings are the result of accumulated chromosomal abnormalities, reflecting an unstable genome in established malignancy.

Quantitative assessment of basement membranes in soft tissue tumours. Computerized image analysis of laminin and type IV collagen

Basement membranes (BMs) in 201 soft tissue tumours were quantified using computerized image analysis of tissues immunostained for laminin and type IV collagen. The purpose of the study was to compare and quantify the extent of BM deposition in a large and varied group of benign and malignant tumours. Laminin and type IV collagen gave similar results. The difference between benign and malignant was statistically highly significant (P = 0.0001), with greater deposition in benign tumours. BM deposition was homogeneous in benign tumours and heterogeneous in sarcomas and appeared to correlate with the degree of differentiation. Some poorly differentiated sarcomas showed cytoplasmic laminin staining but little or no extracellular BM. Immunohistochemical evaluation of BM has some advantages over electron microscopy; specialized equipment is not needed and since large samples can be studied with little sampling error, heterogeneity can be studied more readily. Subjective visual assessment gives a good overall indication of the extent of BM deposition and in many situations is likely to be a suitable alternative to image analysis. Because of staining heterogeneity, BM immunohistochemistry is unlikely to be of significant value in the diagnosis of specific types of sarcoma.

The MAS proto-oncogene is imprinted in human breast tissue

The human MAS proto-oncogene is situated at 6q25.3-q26, a region that is homologous to mouse chromosome 17 where two parentally imprinted genes (Mas and Igf2r) have previously been identified. We investigated the imprinting status of MAS in adult lesions to establish the imprinting status of this gene in humans, as certain imprinted genes are known to have altered imprinting phenotypes in cancer. Of 14 breast samples demonstrating a MAS RT-PCR product, 4 were informative for a polymorphic marker. In all 4 cases, expression of the MAS gene was found to be mono-allelic, indicating the presence of a functional imprint at this locus in human breast tissue.

Multinucleated stromal giant cells of testis

AIMS

This study documents the frequency of multinucleated stromal giant cells within the interstitium of the testis and looks for possible aetiological reasons for this occurrence.

MATERIALS AND METHODS

We examined sections of testes from 150 unselected autopsy cases finding stromal giant cells in 43%. An aetiological association between the occurrence of multinucleated stromal giant cells in this site and hormonal or other pathogenetic influences could not be established.

CONCLUSIONS

In many instances, this occurrence appears to be an age related phenomenon.

Comparison of chromosome 1 aneusomy detected by interphase cytogenetics and DNA ploidy in carcinoma of the breast

Aneuploidy is an important prognostic factor in many cancers. Chromosome 1 abnormalities are present in most breast carcinomas. These may be part of a non-specific increase in DNA (aneuploid status) or represent a restricted chromosomal abnormality. In 16 breast carcinomas we compared chromosome 1 aneusomy with ploidy status. Patients were selected from a mammographically screened population and interphase tumour nuclei were studied by in situ hybridization using a chromosome 1 pericentromeric probe. Ploidy status was assessed by image cytometry on disaggregated cells from paraffin blocks. Of eight cases showing chromosome 1 aneusomy, six (75%) were aneuploid and two diploid. Six (75%) of the eight eusomic cases were aneuploid. This study demonstrates that chromosome 1 aneusomy does not always reflect a gross aneuploid status but, in some tumours, is part of a more restricted chromosomal abnormality. Interphase cytogenetics, possibly using a small panel of pericentromeric probes, may be more sensitive than DNA cytometry for detecting abnormal nuclear DNA content.

Involvement of the appendix in pseudomembranous colitis

Pseudomembranous colitis (PMC) is an inflammatory disorder usually limited to the large intestine and is the consequence of antibiotic associated Clostridium difficile overgrowth with production of its toxin. It has a characteristic gross and microscopic appearance. PMC-like changes, usually associated with peri-operative hypotension and with more extensive gastrointestinal tract involvement, have also been described. In neither clinical setting has pseudomembranous appendicitis been recorded. A case of pseudomembranous appendicitis in a 76 year old woman is described.

BCL-6 and other genomic alterations in non-Hodgkin's lymphoma (NHL)

This study reports on the frequency and disease association pattern of a number of gene rearrangements in a large panel of lymphoid tumours (n = 94). We detected the t(11;14) translocation, involving rearrangement of the BCL-1 locus, in 60% of mantle cell lymphomas. The BCL-2 gene, located at band 18q21, was rearranged in 42% of follicle centre lymphomas (FCL) and in 15% of diffuse large B-cell (DLBC) lymphomas. In this study, 80% of the c-MYC rearrangements were detected in aggressive diffuse lymphoma subsets but, interestingly, 9% of FCL showed involvement of t(8q24) translocation. In our study, rearrangements of the BCL-6 gene at band 3q27 were found in 31% of DLBC lymphomas. Interestingly, 50% of the BCL-6 rearrangement positive lymphoma cases had coexisting gene rearrangements involving all of the aforementioned gene loci. The molecular dissection of these genes will improve our understanding of the genesis of the diverse clinicopathological subtypes.

Comparison of oestrogen receptor assessment in frozen and paraffin sections

Estimation of oestrogen receptors (ER) in breast carcinoma has important therapeutic and prognostic implications. The dextran-coated charcoal (DCC) biochemical technique is being replaced in many institutions by immunohistochemical techniques. The aim of this study was to assess the level of agreement between ER counts in frozen and paraffin sections. Ninety-seven infiltrating breast carcinomas were studied immunohistochemically, for ER in frozen and paraffin sections. Cases were classified as ER-positive if > or = 10% of the tumor cells were positive. Both techniques gave a high level of correlation and agreement. There was complete agreement in classifying cases as ER-positive or ER-negative. ER estimation on only one case was outside 2SD of complete agreement. Oestrogen-receptor content can be assayed satisfactorily in paraffin sections and offers many advantages over the frozen section technique.

Biallelic expression of the IGF2 gene in human breast disease

We examined the imprinting status of the insulin-like growth factor II gene (IGF2) in a series of 20 human breast disease samples to determine if disrupted imprinting (as evidenced by biallelic expression), was a demonstrable mechanism of altered gene expression. These samples included benign (n = 7) and malignant breast lesions (n = 13). Biallelic expression of IGF2 was detectable in 67% of benign and 60% of malignant informative breast lesions. Three informative reduction mastectomies displayed normal IGF2 imprinting. The presence of this alteration in human breast tissue is a novel finding, and may contribute to tumorigenesis, possibly by favouring an enhanced proliferative milieu, during which additional mutations could occur.

Comparison of cytomorphological and architectural heterogeneity in mammographically-detected ductal carcinoma in situ

Many classification schemes have been proposed for ductal carcinoma in situ. Architectural heterogeneity is widely recognized. Cytonuclear grade appears to have greater prognostic significance than architectural pattern. This study assesses heterogeneity using a classification based on cytological grade and compares this to architectural heterogeneity in mammographically detected ductal carcinoma in situ. One hundred and twelve cases were classified according to architectural subtypes and the carcinoma nuclei were graded. Necrosis and microcalcification were assessed. Eighty-four percent of ductal carcinomas in situ had a single nuclear grade, whereas only 39% showed a single architectural pattern. High grade nuclei were present in 87% of cases. Necrosis was associated with high nuclear grade. In contrast to architectural heterogeneity, this study shows little ductal carcinoma in situ heterogeneity when classification is based on nuclear grade. Thus, a cytomorphological classification should have the advantage of consistency and reproducibility in comparison to architecture-based classification systems.

Is use of the pulmonary valve allograft justified as an aortic valve substitute?

Between January 1, 1990, and March 20, 1994, 56 patients had a homograft valve device placed in the aortic position. The mean age at operation was 53.3 years (range 5-77 years). Diagnosis included dominant aortic stenosis in 27 patients (48.2%) and aortic incompetence in 29 (51.8%). Thirteen patients (23.2%) had subacute bacterial endocarditis. Forty-three aortic homografts and 13 pulmonary homografts were placed. Concomitant procedures were performed in 12 patients (21.8%). The hospital mortality was 7.3% (four patients). On follow-up, three pulmonary valves have failed, two between 1 and 5 weeks post implantation. At reoperation a linear cusp fracture was found in all with no evidence of infection. All remaining patients have no, trivial, or mild, aortic regurgitation on echo and remain well. Pulmonary and aortic valves were compared for failure, P = 0.02 suggesting a significant difference between valve substitutes. In conclusion we advise caution in using pulmonary allografts in the aortic position.

Prognostic significance of microvessel density in lymph node negative breast carcinoma

We evaluated the prognostic value of tumor angiogenesis in node negative breast cancer (NNBC). Paraffin-embedded tissues from 87 patients with NNBC were immunostained for factor VIII-related antigen, using one tissue block representative of the invasive edge of the tumor. Sections were scanned at low power to identify "hotspots" of angiogenesis. Microvessel (MV) counts were performed at x200 magnification, using a grid eyepiece graticule. Within each hot spot, three fields (area of field = 0.22 mm2) were counted and averaged. The highest average for a hot spot and the highest single field value was recorded for each case. Patients were stratified into low and high MV groups and their survival compared. There were no differences in disease-free or overall survival between the two groups whether the highest average or the highest single value was used. Microvessel counts did not correlate with other prognostic features, ie, grade, size, estrogen receptor status, c-erb B-2 or accumulated P53 status. Because of the difficulty in assessing angiogenesis that is heterogenous throughout tumors, MV counting may not be suitable for clinical use as a prognostic factor in NNBC. This problem could be addressed in a prospective study involving more extensive tumor sampling.

Amplification of the MDM2 gene in human breast cancer and its association with MDM2 and p53 protein status

The present study reports on the frequency of MDM2 gene amplification and MDM2 protein expression in a series of 100 breast carcinomas and its association with accumulation of the p53 protein. Of the 100 cases, frozen samples for 82 cases were available for Southern blotting. Three of the 82 (4%) demonstrated MDM2 gene amplification of up to 6-fold. Immunohistochemical analysis of the formalin-fixed, paraffin-embedded tumours demonstrated that 7/97 (7%) had nuclear expression for MDM2 in 10-50% of the tumour cells (type 2 staining) and were denoted MDM2+. Two of the MDM2-amplified samples were MDM2+ with one of the two tumours also displaying type 2 p53 nuclear staining. Finally at the protein level, MDM2+ tumours were significantly associated with tumours having low levels of p53 staining (0-10% cells positive) (P = 0.03). We conclude that MDM2 gene amplification occurs at a lower frequency in breast cancer than in non-epithelial tumours. Alterations in MDM2 and p53 may represent alternative pathways in tumorigenesis, but they are not mutually exclusive in all cases.

Chromosome 1 aneusomy, identified by interphase cytogenetics, in mammographically detected ductal carcinoma in situ of the breast

Because of the relative rarity of ductal carcinoma in situ (DCIS) in the premammographic screening era, the unavailability of adequate fresh tissue for culture, and the lack of cytogenetic expertise in most pathology departments, there is little information on karyotypic abnormalities in DCIS. The purpose of this study was to investigate the frequency of chromosome 1 aneusomy in DCIS, using interphase cytogenetic techniques, and to correlate the findings with nuclear grade. Twenty-one cases of DCIS, identified in a mammographically screened population, were studied by in situ hybridization. Chromosome 1 numbers were identified in interphase nuclei in conventional histology sections, using a specific centromeric probe (pUC 1.77). In each case, 100 tumour nuclei were compared with 100 normal nuclei. Eighteen of 21 (86 per cent) cases were aneusomic for chromosome 2. This included 15 of 16 (94 per cent) pure comedo or predominantly comedo DCIS. Fifteen of 16 (94 per cent) DCIS with grade 3 nuclei and 3 of 5 (60 per cent) cases with grade 2 nuclei were aneusomic. One case with grade 3 nuclei (a comedo carcinoma) was negative. We conclude that chromosome 1 aneusomy precedes invasion and is a relatively consistent occurrence in those DCIS with high nuclear grade.

Proliferating cell nuclear antigen: a new prognostic indicator in renal cell carcinoma

Renal cell carcinoma is a tumor, the prognosis and behavior of which remain poorly understood. Proliferating cell nuclear antigen levels have been shown to act as an independent prognostic variable in a variety of malignancies. Proliferating cell nuclear antigen was evaluated in 59 cases of renal cell carcinoma, and the results were correlated with existing clinicopathological variables and survival. Proliferating cell nuclear antigen index (percentage of tumor cells positive for proliferating cell nuclear antigen) did not correlate with stage, grade or ploidy. To assess survival, tumors with proliferating cell nuclear antigen indexes of greater than and less than 60% were compared. The 24 patients with a high index (greater than 60%) had a significantly worse survival than did 35 with a low index (less than 60%, p < 0.001). Therefore, the prognostic potential of proliferating cell nuclear antigen in renal cell carcinoma is promising and may be of clinical value in the management of patients with renal cell carcinoma.

The diagnostic value of silver nucleolar organizer region assessment in breast cytology

Benign and malignant breast lesions in cytologic preparations can be difficult to distinguish. The authors applied the silver nucleolar organizer region (AgNOR) technique to cytologic preparations obtained from surgical specimens to evaluate its diagnostic usefulness in making this distinction. Sixty-two benign and 36 malignant lesions were examined. AgNORs were counted and evaluated using a subjective scoring technique to examine AgNOR size, shape, and clustering. The benign lesions had a mean count of 4.44 AgNORs/nucleus (95% CI, 2.4-6.5) and the malignant cases, 9.52 AgNORs/nucleus (95% confidence interval, 7.4-11.7; P < .0005). The median score for benign cases was 7 and for malignant cases, 13 (P < .0001). With a few exceptions, cases with high counts had high scores. The diagnostic accuracy of combined counting and pattern assessment was 90%. The likelihood ratio for correct diagnosis using AgNOR counting was 14:1 and for AgNOR scoring, 13:1.

Bcl-2 rearrangement in Hodgkin's disease and reactive lymph nodes

The chromosomal translocation t(14;18)(q32;q21), which involves the bcl-2 oncogene, occurs in most follicular lymphomas. Recent evidence suggests that this translocation occurs in Hodgkin's disease, linking its cellular origin and oncogenesis to follicular non-Hodgkin's lymphomas. Using polymerase chain reaction, the authors examined both Hodgkin's disease (n = 60) and reactive lymph nodes (n = 34) for the presence of bcl-2/JH breakpoint fragments, which are indicative of the t(14;18) chromosomal translocation in the major breakpoint region of the bcl-2 gene. The translocation was detected in approximately 10% of both Hodgkin's disease and nonmalignant reactive lymph node cases. These results suggest the possibility that the translocation may occur in the reactive component of Hodgkin's disease and not in the putative malignant cells, the Reed-Sternberg cells. Furthermore, the detection of the translocation in reactive lymph nodes suggests that it may not be the primary factor in the oncogenesis of follicular lymphoma.

Soft tissue and visceral sarcomas in Irish patients. Interim analysis of data obtained by the Dublin Soft Tissue Tumour Panel

The Dublin Soft Tissue Sarcoma Panel was established in 1989 with a view to achieving a unified approach to diagnosis and management of soft tissue and visceral sarcomas. This interim report presents data on 265 prospectively-evaluated patients and on a separate retrospective series of 126 patients. The patients in the prospective series were treated by 93 different surgical and medical specialists. Tumours presented in all anatomic sites and ranged in size from 0.2 to 60 cm. Leiomyosarcoma was the commonest tumour type. Eighty-nine tumours were inoperable at clinical presentation. There was a consensus panel diagnosis in over 90%, non-neoplastic reactive lesions and primitive round cell tumours being the most difficult cases diagnostically. Management, including onward referral for chemotherapy or radiation therapy, was inconsistent. The 2-year survival figures were: 43% (1989-91) and 37% (1980-88). These findings should provide a basis for the evaluation of coherent treatment strategies for Irish sarcoma patients.

Screening for breast cancer in Ireland: the Eccles Breast Screening Programme

The Eccles Breast Screening Programme is a population-based screening programme for breast cancer, based at the Mater Misericordiae Hospital, Dublin. It began in 1989 simultaneously with similar programmes in Belgium, France, Greece, Portugal and Spain. The objectives of the Eccles Programme are: (i) to evaluate the impact of mammographic screening on morbidity and mortality from breast cancer in Irish women; and (ii) to address the feasibility and potential value of a national breast cancer screening programme. The specific group targeted for screening is women born in 1925 to 1940 inclusive, in a defined geographical area comprising north Dublin City and County, and Counties Cavan and Monaghan. The areas combined comprise 16% of the country's population; just over 29,000 women were invited for screening. An analysis of the demographic and socioeconomic features of the target population reveals that it represents the total population remarkably well. Participants were invited from a population register to attend one of two screening units. Follow-up treatment for those with abnormalities takes place predominantly at the Mater Hospital where the facilities of the Departments of Pathology, Surgery and Oncology have been made available to the programme. Almost 18,000 women had a mammogram in the first round of screening, an overall response rate of 62%. A total of 129 cancers were detected, a prevalence of breast cancer of 7.2 per 1,000. Of those, 15 (11.6%) were entirely intraduct, and an additional 7 (5.4%) had minimal invasion. This is considerably higher than the proportion of intraduct cancers seen in referral practice populations.

Comparable prognostic factors and survival in elderly patients with aggressive non-Hodgkin's lymphoma treated with standard-dose adriamycin-based regimens

We retrospectively analysed the prognostic factors at diagnosis, clinical response, and survival of 192 patients with newly diagnosed aggressive NHL treated in a single institution between 1985 and 1991. Overall, 37.5% (72/192) of patients were 65 years or older (average age 71 years, range 65-85 years), and 62.5% (120/192) were under 65 years of age (average age 45, range 16-64 years). All patients were completely staged and had intermediate- or high-grade NHL. 127 patients were treated on similar regimens with the same chemotherapy dose intensity irrespective of age. Standard-dose m-BACOD (methotrexate, bleomycin, Adriamycin, cyclophosphamide, vincristine, prednisone) or CHOP were used to treat 60/72 (83%) elderly patients and 67/120 (56%) patients less than 65 years. The remaining younger patients were treated with more intensive regimens. There were no significant differences between the groups with regard to stage, histological grade, cell type, elevated LDH, number of extranodal sites, presence of B symptoms, or bulky disease. More elderly patients had a significantly (p < 0.02) poorer performance status (PS), with 42% (25/60) having a PS of 2 or more, compared to 22% (15/67) in those less than 65 years of age. Elderly patients had an inferior complete response rate, 65% versus 76%. However, overall response rates of 95% and 92% were similar. The disease-free survival at 3 years for complete responders in elderly patients was 74% compared to 82% in those under 65. The comparable 3-year overall survival was 59% and 62%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

A quantitative immunohistochemical evaluation of lentigo maligna and pigmented solar keratosis

Pigmented solar keratosis (PSK) is sometimes clinically indistinguishable from lentigo maligna, a form of malignant melanoma in situ. Occasionally histologic diagnosis is also difficult. Accurate diagnosis is essential, as the treatment and prognosis for each condition differs considerably. To determine whether there was a significant overlap in the number of melanocytes in these sun-damaged skin lesions, or whether immunohistochemistry might be helpful in the differential diagnosis, the authors examined skin biopsy specimens from 26 patients with obvious lentigo maligna and 15 patients with PSK using 3 monoclonal antibodies (HMB-45, NK1C3, and vimentin) and 1 polyclonal antibody (S-100 protein). Formalin-fixed paraffin sections were immunostained with each of the above antibodies, and immunopositive cells per mm2 of epidermis were counted. The difference between lentigo maligna and PSK counts was statistically significant at a level of P < .0001; furthermore, there was almost no overlap between the two groups. The sensitivity for the diagnosis of lentigo maligna was high with all antibodies. However, HMB-45 had the highest sensitivity and the lowest false-positive rate and was visually most pleasing. Using a cut-off count of 60 cells per mm2 of epidermis, HMB-45 had a sensitivity of 96% and a 0% false-positive rate. In this study, lentigo maligna was easily differentiated from PSK. The real value of immunohistochemistry in the differential diagnosis of these pigmented lesions should be tested in a prospective study using cases that are difficult to diagnose by routine light microscopy.

Pleomorphic rhabdomyosarcoma in adulthood. Analysis of 11 cases with definition of diagnostic criteria

Currently, pleomorphic rhabdomyosarcoma (RMS) in adults is considered to be extremely rare or nonexistent. The authors have identified 11 cases of pleomorphic RMS using the following criteria: pleomorphic sarcoma occurring within voluntary muscle, large polygonal or strap-like cells with copious eosinophilic cytoplasm, desmin and myoglobin immunoreactivity, or ultrastructural evidence of sarcomeric differentiation. Ten patients were male, the median age at presentation was 56 years (range, 27-84), and the thigh (seven cases) was the most common site. Of eight cases with clinical follow-up, one patient is alive at 20 months, and seven died 2 to 28 months following diagnosis. The tumors were generally patternless, but several had storiform areas. Cross-striations were not identified. Immunostaining for muscle-related antigens was positive as follows: desmin (in 10 of 11 cases), myoglobin (in 10 of 11 cases), actin HHF-35 (in all 11 cases), smooth-muscle actin (in six of eight cases), sarcomeric actin (in six of nine cases), and fast myosin (in five of five cases). Staining for S-100 protein was negative in all cases. On electron microscopy (six cases), two tumors had well-differentiated rhabdomyoblasts with sarcomeres, Z-disks, and hexagonal arrays of myofilaments; three were poorly differentiated; and one contained immature mesenchymal cells only. Pleomorphic RMS can be distinguished from other pleomorphic sarcomas provided that well-fixed tumor tissue is available for immunohistochemical staining and electron microscopy. We consider that this distinction is important in view of the poor prognosis associated with pleomorphic RMS in this series.

The detection of specific gene rearrangements in non-Hodgkin's lymphoma using the polymerase chain reaction

Characteristic gene rearrangements are present in most non-Hodgkin's lymphomas (NHL). These are usually detected by Southern blotting techniques. In this study, the ability of the polymerase chain reaction (PCR) to detect the t(14;18) chromosomal translocation and immunoglobulin heavy chain (IgH) gene rearrangement was evaluated. DNA from 14 follicular and 42 diffuse B-cell lymphomas was examined using oligonucleotide primers specific for opposing sides of the IgH gene rearrangement on chromosome 14 (towards conserved VH and JH sequences) and opposing sides of the t(14;18) chromosomal translocation (towards the major breakpoint region of the bcl-2 gene on chromosome 18 and conserved JH sequence on chromosome 14). The t(14;18) translocation was detected in 57% of follicular lymphomas and 21% of diffuse B-cell lymphomas. Clonal IgH gene rearrangements using PCR were detected in 50% follicular and 52% of the diffuse lymphomas. Either or both of these rearrangements were detected in 93% follicular and in 59% of diffuse lymphomas. PCR is a rapid and easy technique that can detect the abnormal rearrangement of the bcl-2 gene and clonal IgH rearrangement, indicating the presence of lymphoma. This may be of benefit in monitoring response to therapy and in predicting prognosis in this disease.

A study of regional distribution of renal blood flow using quantitative autoradiography

Quantitative autoradiography utilizing [14C]iodoantipyrine was used to measure regional renal blood flow in anesthetized rats. This technique allowed blood flow in any region of the kidney to be measured with a resolution of 100 microns. There was no significant difference between flow to polar and middle regions of the renal cortex [875 +/- 57 vs. 926 +/- 71 (SE) ml.100 g-1 x mm-1]. Areas of high optical density in renal cortex corresponded to peritubular capillaries. Mean cortical blood flow was three times greater than mean medullary blood flow. Outer medullary blood flow was uniform but significantly higher than inner medullary blood flow (272 +/- 16 vs. 45 +/- 7 ml.100 g-1 x mm-1; P < 0.001).

Tissue characterization and assessment of preoperative chemotherapeutic response in musculoskeletal tumors by in vivo 31P magnetic resonance spectroscopy

This study investigates the potential of in vivo 31P magnetic resonance spectroscopy (MRS) to characterize musculoskeletal tumors and to determine preoperative levels of histological necrosis, which is an important clinical indicator of patient response. Pretherapy MRS was performed on 28 patients with large musculoskeletal tumors: 13 with osteosarcoma, 3 with chondrosarcoma, 5 with malignant fibrous histiocytoma, 1 with desmoid tumor, 1 with Ewing's, 2 with hemangioendothelioma, 1 with myxoid liposarcoma, 1 with synovial cell sarcoma, and 1 with rhabdomyosarcoma. Fifteen patients had follow-up MRS examinations after commencement of chemotherapy (mean of five/patient), eight of whom have now had surgery. Elevated levels of PMEs (P < 0.01), P(i) (P < 0.01), and PDEs (P < 0.02) as well as elevated tumor pH (P < 0.05) were observed in all patients. The synovial cell sarcoma was characterized by high levels of PMEs (> 20%) and low pH (pH 6.76). This contrasted with the spectra obtained from the malignant fibrous histiocytomas which had high levels of PDEs (17 +/- 5%). Reductions in PDE levels postchemotherapy were associated with a high degree of necrosis (> 90%) at surgery, while an increase in PDE levels was associated with a low level of histological necrosis. Likewise, reductions in the ratios PDE/NTP and PDE/PCr and an increase in P(i)/PDE were also associated with a high level of necrosis.

31P MRS as an early prognostic indicator of patient response to chemotherapy

In this study 31P spectral changes were closely monitored following the initial administration of cytotoxic drugs and related to five parameters of patient response. Pre- and postchemotherapy 31P MRS examinations were performed on 16 patients with large, malignant tumors. These included four tumor types: (i) lymphoma (n = 7), (ii) breast carcinoma (n = 4), (iii) musculoskeletal tumors (n = 4), and (iv) adenocarcinoma (n = 1). A mean of 5 spectra/patient (range 2-10) was performed following the initial chemotherapy. The spectral trends exhibited by 14 of 16 patients reached "points of maximum change," after which they began to revert toward prechemotherapy values. In 2 of 16 patients that did not respond to the initial chemotherapy regimen, no spectral trends were observed. The degree of change of certain spectral parameters, namely, decreases in PME, PME/PDE, PME/PCr, PME/NTP, PDE/PCr, and tumor pH, as well as increases in the ratios Pi/PME and Pi/PDE, were associated with good patient response and separated responders from nonresponders. Pi/PME appears the most promising for discriminating partial from complete responders.

Proliferating cell nuclear antigen counts in formalin-fixed paraffin-embedded tissue correlate with Ki-67 in fresh tissue

Cell proliferation can be studied by a variety of techniques. However, most require fresh tissue. To evaluate cell proliferation in formalin-fixed paraffin-embedded sections, the authors immunohistochemically studied 35 tumors and 11 samples of normal/hyperplastic tissue with PC10, a monoclonal antibody directed against proliferating cell nuclear antigen. Results were compared with those obtained with Ki-67 on fresh tissues. There was no significant difference between proliferating cell nuclear antigen and Ki-67 counts, which were strongly correlated (r = 0.8). Proliferating cell nuclear antigen positivity was easier to evaluate because morphology was better preserved in formalin-fixed tissue. The authors conclude that PC10 is an alternative to Ki-67 in evaluating cell proliferation and has the advantage of reacting with formalin-fixed paraffin-embedded tissue.

Argyrophylic nucleolar organiser regions (AgNOR's) as a prognostic indicator in breast carcinoma

Silver staining nucleolar organiser regions (AgNOR's) were determined in archival histological specimens of breast carcinoma. Representative samples from forty-eight female patients were counted manually for AgNOR's--median 3.85 (range 1.1-10.2 AgNOR's per cell). Taking the median value of 3.85 as a cutoff, the patients were divided into two groups: A = Those with AgNOR counts > 3.85; B = Patients with AgNOR counts < or = 3.85. The 5 year survival was 21% in group A and 85% in group B (p < 0.001). There was no significant correlation between AgNOR's and tumour size, lymph node status, tumour grade, menopausal status and oestrogen receptors. We conclude that nucleolar organiser regions may be useful as a prognostic indicator in breast carcinoma especially in patients in whom other prognostic information is unavailable.

Myocardial collagen network in dilated cardiomyopathy. Morphometry and scanning electron microscopy study

Although some form of myocyte damage is probably the main abnormality responsible for heart failure in dilated cardiomyopathy, abnormalities of the supporting interstitial collagen meshwork also occur. To see if abnormal collagen could be detected in cardiomyopathic hearts, which did not have interstitial fibrosis by routine light microscopy, we examined interstitial collagen using scanning electron microscopy and a novel digestion technique. Cardiomyopathetic collagen fibrils were significantly thicker and more densely packed than normal. We conclude that an ultrastructural collagen abnormality occurs early in dilated cardiomyopathy, this abnormality may contribute to the pathophysiology of this disease.

Intermediate filament expression in carcinoid tumours

Twenty-eight carcinoid tumours were stained with monoclonal antibodies to epithelial and neural related intermediate filaments. All were found to express epithelial markers, and none expressed neural markers. These results support the theory that carcinoids are of epithelial, rather than neural crest origin.

Soft tissue and visceral sarcomas in Irish patients. A preliminary report from the Dublin Soft Tissue Tumour Panel

Sarcomas of the soft tissues and viscera are a diverse group of uncommon neoplasms that often present difficult diagnostic and management problems. The Dublin Soft Tissue Tumour Panel prospectively reviewed pathology material from 137 patients of four Dublin teaching hospitals between January 1989 and August 1990. The prevalence of sarcomas in Irish patients was found to be similar to that estimated for the United States. The most common sarcoma of soft tissues was malignant fibrous histiocytoma (14) and the most common visceral sarcoma was leiomyosarcoma (10). The most problematic diagnoses were 3 peripheral neuroepitheliomas (extraskeletal Ewing's sarcomas) which occurred in patients aged 19-27 years, distinctly younger than the typical adult sarcoma patient. Clinical follow-up is in progress and will be combined with the findings of a linked retrospective study, to facilitate evaluation of all aspects of management.