What we need to know about cancer genes.
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Cell Adhesion Molecules↗
Biomedical subjects
A S Leong
Publications and source records attributed to A S Leong.
Immunostaining of estrogen receptor, progesterone receptor, MIB1 antigen, and c-erbB-2 oncoprotein in cytologic specimens: a simplified method with formalin fixation.
An effective but simple fixation protocol for the immunocytochemical staining of cytologic smears for estrogen and progesterone receptors, the Ki-67 antigen (using MIB1 antibody), and c-erbB-2 protein is described. One hundred twenty-seven smears from a variety of malignant and benign breast lesions showed good preservation of antigenicity when subjected to the following fixation protocol: Freshly made smears were air-dried for 20 min to 14 h at 22 degrees C before immersing in 10% buffered formalin for 2-14 h. Immunostaining followed microwave-stimulated epitope retrieval. There was strong concordance of staining with corresponding tissue sections in 15 cases of malignant tumors (ER: r = 0.7381; PR: r = 0.6684; MIB1: r = 0.7234). Immunostaining staining, when delayed for 5-10 days in about half the smears, showed no noticeable difference in reactivity, attesting to effective storage of the formalin-fixed smears at room temperature.
Biomarkers, Tumor↗
A simple index to predict prognosis independent of axillary node information in breast cancer.
BACKGROUND: Since the course of breast cancer is often unpredictable, we wished to develop a model using characteristics of the primary tumour alone to predict prognosis. METHODS: Several tumour features were determined, and after a median follow-up duration of 65 months, multivariate analysis identified tumour size and grade, oestrogen receptor concentration, axillary lymph node metastasis and tumour cell proliferation fraction (MIB-1 count) as being independently associated with increases in risk for both relapse and death from breast cancer. A prognostic model was constructed using tumour size and grade, oestrogen receptor concentration and MIB-1 count only. A score of 1 for each was given to tumour size > 20 mm, tumour grade 2 or 3, oestrogen receptor concentration < 10 fmol/mg cytosol protein and MIB-1 count > 9%. Five groups established by assigning a combined score of 0, 1, 2, 3 or 4 for each patient were analysed for their associations with disease-free and overall survivals. RESULTS: This preliminary model predicted 5-year survival rates of 97, 91, 85, 68 and 50% for the five groups. The model was further simplified by excluding tumour grade from the analysis. The revised model identified four risk groups with predicted 5-year survival rates of 91, 86, 66 and 52%. This model, the Adelaide prognostic index, was also able to identify four risk groups in both node-negative and node-positive patients. CONCLUSIONS: The Adelaide prognostic index can be used to predict prognosis even in the absence of axillary lymph node information.
Antigens, Nuclear↗
Vimentin expression is not associated with poor prognosis in breast cancer.
The clinical significance of vimentin intermediate filament (VIF) expression was studied in relation to other established prognostic parameters in primary breast cancer. Archival tumour samples embedded in paraffin were examined by immuno-histochemistry with monoclonal antibodies (MAbs) to VIF, p53 protein and cell proliferation marker MIB-I. The vimentin staining pattern was heterogeneous, but in vimentin-positive areas > 80% of the tumour cells were positive. There was no association between vimentin expression and tumour size or the number of axillary lymph nodes involved. Vimentin expression was significantly associated with high-grade tumours, absence of hormone receptors, increased p53 expression and high tumour proliferation fraction as estimated by MIB-I count. Despite these associations with several recognised features of tumour aggressiveness, vimentin expression was not associated with increase in risk of relapse or death from breast cancer.
Antibodies, Monoclonal↗
Relationship between p53 gene abnormalities and other tumour characteristics in breast-cancer prognosis.
The prognostic significance of p53 gene abnormalities was investigated in 919 primary breast-cancer patients. p53 expression and tumour-cell proliferation fraction determined by MIB-1 count, p53 exon 5 and 6 mutations and HER-2/neu oncogene amplification were detected by immunohistochemistry, PCR-SSCP and slot-blot hybridization, respectively. Increased MIB-1 count, p53 expression, HER-2/neu oncogene amplification and p53 mutations were detected in 33%, 29%, 10% and 8% of tumours, respectively. Statistically significant associations were observed between p53 expression or MIB-1 count and age below 50 years, high-grade tumours, medullary carcinomas, and absence of hormone receptors. p53 mutations were associated with increased MIB-1 count, HER-2/neu oncogene amplification and absence of hormone receptors, but not with age, tumour size or grade, histological subtype, or the number of axillary nodes involved. After a median follow-up of 66 months, p53 expression was observed to be associated with significant increases in risk of both relapse and death from breast cancer, but not after adjusting for the effect of other parameters. In these analyses, MIB-1 count, and not HER-2/neu oncogene amplification, was an independent predictor of prognosis. In node-negative patients, only p53 exon 5 and 6 mutations and MIB-1 count were associated with a statistically significant increase in risk of death from breast cancer, independent of tumour size and ER concentration. We conclude that tumour-cell proliferation fraction, as measured by MIB-1 count, is the most useful parameter of breast-cancer prognosis, with the exception of ER, tumour size and the number of axillary nodes involved.
Adult↗
Immunostaining of cell preparations: a comparative evaluation of common fixatives and protocols.
Immunostaining of cytologic preparations has been beset by problems of inconsistency, high background staining, and the requirement of different fixatives for different antigens. This study sought to identify a universal fixative and a simple fixation protocol suitable for a wide range of tissue antigens commonly employed for cytologic diagnosis. In an analysis of 23 fixation protocols involving acetone, acetone/methanol, acetone/formalin, glutaraldehyde, ethanol, methanol, and formal saline, fixation in 0.1% formal saline overnight at 27 degrees C followed by 10 min fixation in 100% ethanol produced the most consistent and optimal preservation of immunoreactivity which could be further enhanced by pre-treatment with microwaves for epitope retrieval. Blocking of endogenous peroxidase was not necessary with this fixation protocol. Provided the smears were well air-dried (for at least 14 hr) prior to immersion in formal saline, there was no need to employ adhesive-coated glass slides. The smears could be kept at 27 degrees C (room temperature) for at least 7 days and at -70 degrees C for 5 wk without loss of immunoreactivity as air-dried smears or after fixation in formal saline. One hundred percent acetone and 100% ethanol produced good morphology and immunoreactivity but a high level of background staining, whereas acetone-based mixtures resulted in inconsistent immunostaining.
Acetone↗
Fine-needle aspiration biopsy for the diagnosis of lymphoma: a perspective.
Fine-needle aspiration (FNA) has become a widely used diagnostic tool and it remains one of the most rapid and cost-effective methods of assessing a variety of pathologic conditions. However, FNA as a method of evaluation of enlarged lymph nodes has been approached with a greater degree of caution and reservation, largely because Hodgkin's disease and the non-Hodgkin's lymphomas represent a diverse group of neoplasms, which is mirrored by a large range of histopathologic and cytologic appearances. For these reasons, adjunctive techniques such as immunohistochemical staining, cytogenetics, and molecular techniques have been introduced to improve the diagnostic accuracy. While such procedures have made significant contributions to the identification and typing of lymphomas, there is still a requirement for a simple and rapid diagnostic procedure for the patient who presents with persistent lymphadenopathy. Light microscopic examination of FNA smears fulfills this role, provided its limitations and pitfalls are recognised.
Biopsy, Needle↗
Malignant rhabdoid tumor in adults--heterogenous tumors with a unique morphological phenotype.
Five cases of malignant rhabdoid tumors in adult patients are described. The tumors were characterized by sheets of poorly cohesive cells with distinctive hyaline cytoplasmic inclusions and eccentrically placed large vesicular nuclei with prominent nucleoli. A variety of lineage differentiation was shown by immunohistochemistry and electron microscopy, the lesions representing leiomyosarcoma, gastric carcinoma, epithelioid sarcoma, Merkel cell carcinoma and desmoplastic small round cell tumor. Previously reported cases of rhabdoid tumors in adults support the contention that such tumors, although of distinctive morphologic phenotype, are of heterogenous lineage differentiation, and do not represent a distinct clinicopathologic entity.
Adult↗
Signet-ring carcinoma of the prostate.
A case of prostatic signet-ring adenocarcinoma is described in a man with a history of open prostatectomy for prostate carcinoma (18 years previously). Immunostaining confirmed the prostatic origin of the signet-ring tumor which stained for prostatic acid phosphatase (PSAP) and prostate specific antigen (PSA). Cytokeratin immunostaining showed the vacuoles to be true lamina with clear and distinct outlines, the feature confirmed by ultrastructural examination. This aggressive tumor is an uncommon but distinct variant of primary prostatic carcinoma which should be distinguished from artefactual vacuolation of tumor, inflammatory and stromal cells, and metastatic disease.
Aged↗
Microwaves in diagnostic immunohistochemistry.
Immunostaining has been shown to be clearly superior in tissues immersed in normal saline and fixed by primary exposure to microwaves (MWs) as compared to that fixed routinely in 10% buffered formalin. MWs have also been applied to dry cryostat sections and to accelerate antibody-antigen reactions in the staining of labile lymphocyte membrane antigens in such sections. MWs can also be employed to accelerate immunostaining in paraffin sections, producing significant reduction in all stages of the staining procedure. The more recent application of MWs for epitope retrieval has made an important step towards not only producing better immunostaining of routinely fixed tissues but also towards the standardisation of the immunostaining process. MW-irradiation of paraffin-embedded sections in 10 mMol citrate buffer solution produced, with few exceptions, increased intensity and extent of immunostaining of a wide variety of tissue antigens. Moreover, proteolytic enzyme digestion was not necessary in most instances and some primary antibodies could be used at higher working dilutions.
Antigen-Antibody Reactions↗
Immunostaining of cytologic specimens.
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Biopsy, Needle↗
Tumor genes and their proteins in cytologic and surgical specimens: relevance and detection systems.
Oncogenesis is the consequence of a series of genetic alterations that allow unrestrained cellular growth, tissue invasion, and eventual metastases. Tumor-related genes can be classified into functional categories. Proto-oncogenes/oncogenes have a stimulatory role in cell growth, and the inactivation of cancer-suppressor genes/antioncogenes results in the loss of cell cycle regulation. More recently, three other groups of tumor-related genes have been recognized. They include the antiapoptosis genes which protect from programmed cell death, the antimetastasis genes, and multidrug resistance genes. Besides aiding in tumor diagnosis, the detection of such tumor-associated genes and their products allows the identification of individuals with an inherited predisposition to neoplastic growths, and the overexpression of many of these oncogene products has been shown to be a potential marker of tumor behavior and a predictor of treatment outcome and response. The ability to utilize DNA and RNA probes for nucleic acid hybridization and polymerase chain reaction procedures in cell and tissue preparations of solid tumors and lymphoid proliferations expands and complements the information provided by immunohistochemical techniques. These probes allow direct visualization and correlation of specific genes and their protein products with cytomorphologic features, and form a powerful addition to the armamentarium of the cytopathologist and surgical pathologist.
Animals↗
Multiple piloleiomyomas in a cat.
The microscopical and immunohistochemical features of a rare cutaneous leiomyoma in a cat are described. The principal characteristics of this tumour were multiple bundles of smooth muscle, either discrete or conjoined, with numerous collagen fibres between the muscle cells, and osteoid metaplasia. The tumour was designated a piloleiomyoma as it was considered to have arisen from the arrector pili muscles.
Animals↗
Antigen-specific B cells in tissues after oral typhoid vaccination.
Six human subjects who were to receive elective bowel surgery for a variety of diseases were vaccinated with the oral typhoid vaccine, Ty21a. Intestinal tissue (ileum in two, large intestine in four) removed 7-26 days after the first dose of vaccine was examined for the presence and distribution of antigen-specific B cells. This was compared with intestinal tissue derived from two unvaccinated controls. A number of B cell differentiation antigens were also assessed on these cells by immunofluorescence using dual-labelling. Antigen-specific cells were found randomly distributed in the lamina propria of all the vaccinated subjects in low frequency (6 +/- 0.5 to 37 +/- 31 [mean +/- s.e.m.] antigen specific cells/10 mm2 of tissue). The lymphocyte differentiation antigens CD45RA, CD45RO, L-selectin, CD-11a CD-38, CD-44 and VLA-4 were all found on antigen-specific cells, but no particular pattern was recognizable in this small series of six subjects with different disease processes affecting the intestine.
Administration, Oral↗
A morphological and immunohistochemical study of 25 cases of so-called sclerosing haemangioma of the lung.
The so-called sclerosing haemangioma of the lung is an uncommon tumour with predilection for Chinese women. Twenty-five cases showed a predominantly solid/cellular pattern in three, a haemorrhagic/angiomatoid pattern in three, a papillary pattern in one, a sclerotic pattern in one, and in seventeen, a mixed pattern was observed. Immunostaining revealed the expression of epithelial membrane antigen, vimentin (V9), and CD68 (KP1) in all tumours, cytokeratin in 23 (Cam 5.2 and MNF116), S-100 protein in 22 and alpha-smooth muscle actin in 23 tumours. All tumours were negative for surfactant, factor VIII-related antigen, CD34 and MAC387. There was strong labelling for progesterone receptor protein in 20 tumours, and oestrogen receptor protein was weakly stainable in 13 tumours. The histogenesis of sclerosing haemangioma of the lung is controversial and origin from pneumocyte, histiocyte, mesothelial, endothelial and Clara cell has been suggested. Our immunohistochemical findings, in the largest series studied to date, indicated a cytokeratin+, vimentin+, epithelial membrane antigen+, alpha-smooth muscle actin+, CD68+, oestrogen+, progesterone+ phenotype, confirming an epithelial lineage but which does not clearly correspond to any recognized cell in the respiratory system. The distinct expression of progesterone and oestrogen receptor proteins correlates with the predilection of this tumour for women.
Adult↗
Dual staining of lymphocyte membrane antigens with colloidal gold and biotinylated horseradish peroxidase.
Double immunoenzymatic labelling procedures for the localization of antigens on cells in tissue sections using horseradish peroxidase (HRP) and alkaline phosphatase have been described previously, but mainly for detecting antigens on different cells. With this type of staining when two antigens are present on the same cell, an optimal colour combination that shows a high contrast between the basic colour of each enzyme substrate product is difficult to achieve and the interpretation of their mixed colour intermediate is subjective. We present a method for the simultaneous demonstration of two antigens on the same cell. The method can be used to label either single cells in suspension, or cells in paraffin fixed tissue, using a combination of a particulate label, colloidal immunogold-silver, and an enzymatic label HRP-DAB. The method is easy to perform and utilises commercially available staining kits.
Antigens, CD↗
Nuclear shape and prognosis following orchiectomy in stage D2 prostate cancer.
In this study, we have examined whether tumor grade and morphometric nuclear features can predict the outcome of treatment by orchiectomy in patients with stage D2 prostate cancer. Two outcome groups based on duration of survival postorchiectomy were examined, a bad outcome group of 63 patients who died from prostate cancer within 12 months and a good outcome group of 34 patients who survived beyond 5 years. Tumors were histologically classified as well (17%), moderate (17%), or poorly differentiated (66%). Tumor grade and patient outcome were significantly associated (Mann-Whitney test; P < 0.005), with 76% of poorly differentiated tumors in the bad outcome group, and 65% of well-differentiated tumors in the good outcome group. Using discriminant function analysis, tumor grade correctly predicted outcome in 70% of cases. A statistically significant difference was also detected in nuclear shape values between the two outcome groups (P < 0.05) and histological grades (P < 0.05). Using discriminant function analysis, 51% of cases were correctly classified into outcome groups using nuclear shape factors, a figure which rose to 65% when all nuclear morphometric features were used. This demonstrates that nuclear morphometric features are of no clinical value in predicting the outcome of treatment in stage D2 disease. Furthermore, these evaluations cannot select patients who might be spared orchiectomy on the basis of a predicted poor response. However, nuclear shape and variance measurements of benign glandular epithelial cells within cancerous prostates were significantly different from those of malignant cells (P < 0.005). We conclude that, while video image analysis of prostatic nuclear shape can reliably discriminate between benign and malignant cells, nuclear morphometric features are of minimal prognostic value in men with stage D2 prostate cancer treated by androgen ablation.
Aged↗
IgG-mediated phagocytosis in regenerated splenic tissue.
The risk of severe infections after splenectomy is well established. Operations such as auto-transplantation, splenic artery ligation or partial resection have been advocated for the retention or regeneration of splenic tissue following splenic trauma. The potential of such tissue to protect from infection is unclear. The ability of splenic tissue to phagocytose IgG opsonized syngeneic erythrocytes was measured in rats 6 months following splenectomy and splenic autotransplantation, splenic artery ligation, total or partial splenectomy, and compared with eusplenic controls. In eusplenic and partially splenectomized rats 71% of the label was cleared at 3 h, compared with approximately 50% in rats following total splenectomy, splenectomy and splenic autotransplantation or splenic artery ligation. The autotransplanted and the ligated splenic tissue cleared less than 10% compared with control spleen, but there was no difference between them when clearance was expressed as uptake per gram of tissue. Splenic autotransplants and ligated spleens were small and histologically abnormal, with an increase in the red pulp, significantly less white pulp and marginal zone, and the frequent absence of a central arteriole in the white pulp. The clearance of label was proportional to the amount of red pulp in the tissue, although the red pulp from the regenerated tissues was not as efficient at phagocytosis as control red pulp. The tissue which regenerated following autotransplantation or splenic artery ligation did not result in greater clearance of erythrocytes from the circulation than that which occurred in splenectomized rats.
Animals↗