c-KIT and PDGFRA in breast phyllodes tumours: overexpression without mutations?

AIM

To study the immunoexpression and mutational status of c-KIT and PDGFRA in a series of benign and malignant phyllodes tumours of the breast.

MATERIAL/METHODS

Nineteen phyllodes tumours (13 benign and six malignant) were analysed by immunohistochemistry for the expression of c-KIT and PDGFRA. Direct sequencing of exons 9, 11, 13, and 17 of the c-KIT gene and exons 12 and 18 of PDGFRA was performed to check the mutational status of these two genes.

RESULTS

c-KIT expression was found in 12 of the 19 cases (six of the 13 benign cases and all six malignant ones) and PDGFRA expression was seen in two of the 19 cases (one benign and one malignant case); the 2415 C>T alteration in exon 17 of the c-KIT gene was found in two cases (both benign); the intronic insertion IVS17-50insT and the 2866 G>T alteration in the coding region of exon 18 of the PDGFRA gene were also found in two cases (one malignant and one benign). However, the activating mutations described for these genes in gastrointestinal stromal tumours were not present.

CONCLUSION

c-KIT expression is a frequent finding in phyllodes tumours, particularly in malignant cases; however, no activating mutations similar to those described for gastrointestinal stromal tumours were found. The PDGFRA does not seem to be an alternative pathway to tumour development in phyllodes tumours because neither expression nor activating mutations were noteworthy.

Discrepancies in current practice of pathological evaluation of sentinel lymph nodes in breast cancer. Results of a questionnaire based survey by the European Working Group for Breast Screening Pathology

AIMS

To evaluate aspects of the current practice of sentinel lymph node (SLN) pathology in breast cancer via a questionnaire based survey, to recognise major issues that the European guidelines for mammography screening should address in the next revision.

METHODS

A questionnaire was circulated by mail or electronically by the authors in their respective countries. Replies from pathology units dealing with SLN specimens were evaluated further.

RESULTS

Of the 382 respondents, 240 European pathology units were dealing with SLN specimens. Sixty per cent of these units carried out intraoperative assessment, most commonly consisting of frozen sections. Most units slice larger SLNs into pieces and only 12% assess these slices on a single haematoxylin and eosin (HE) stained slide. Seventy one per cent of the units routinely use immunohistochemistry in all cases negative by HE. The terms micrometastasis, submicrometastasis, and isolated tumour cells (ITCs) are used in 93%, 22%, and 71% of units, respectively, but have a rather heterogeneous interpretation. Molecular SLN staging was reported by only 10 units (4%). Most institutions have their own guidelines for SLN processing, but some countries also have well recognised national guidelines.

CONCLUSIONS

Pathological examination of SLNs throughout Europe varies considerably and is not standardised. The European guidelines should focus on standardising examination. They should recommend techniques that identify metastases > 2 mm as a minimum standard. Uniform reporting of additional findings may also be important, because micrometastases and ITCs may in the future be shown to have clinical relevance.

Consistency of staining and reporting of oestrogen receptor immunocytochemistry within the European Union—an inter-laboratory study

To assess the variability of oestrogen receptor (ER) testing using immunocytochemistry, centrally stained and unstained slides from breast cancers were circulated to the members of the European Working Group for Breast Screening Pathology, who were asked to report on both slides. The results showed that there was almost complete concordance among readers (kappa=0.95) in ER-negative tumours on the stained slide and excellent concordance among readers (kappa=0.82) on the slides stained in each individual laboratory. Tumours showing strong positivity were reasonably well assessed (kappa=0.57 and 0.4, respectively), but there was less concordance in tumours with moderate and low levels of ER, especially when these were heterogeneous in their staining. Because of the variation, the Working Group recommends that laboratories performing these stains should take part in a external quality assurance scheme for immunocytochemistry, should include a tumour with low ER levels as a weak positive control and should audit the percentage positive tumours in their laboratory against the accepted norms annually. The Quick score method of receptor assessment may also have too many categories for good concordance, and grouping of these into fewer categories may remove some of the variation among laboratories.

Pathological work-up of sentinel lymph nodes in breast cancer. Review of current data to be considered for the formulation of guidelines

Controversies and inconsistencies regarding the pathological work-up of sentinel lymph nodes (SNs) led the European Working Group for Breast Screening Pathology (EWGBSP) to review published data and current evidence that can promote the formulation of European guidelines for the pathological work-up of SNs. After an evaluation of the accuracy of SN biopsy as a staging procedure, the yields of different sectioning methods and the immunohistochemical detection of metastatic cells are reviewed. Currently published data do not allow the significance of micrometastases or isolated tumour cells to be established, but it is suggested that approximately 18% of the cases may be associated with further nodal (non-SN) metastases, i.e. approximately 2% of all patients initially staged by SN biopsy. The methods for the intraoperative and molecular assessment of SNs are also surveyed.

p63 Staining of myoepithelial cells in breast fine needle aspirates: a study of its role in differentiating in situ from invasive ductal carcinomas of the breast

AIMS

One of the limitations of fine needle aspiration biopsy (FNAB) of the breast is in distinguishing invasive carcinoma (IDC) from ductal carcinoma in situ (DCIS). It has been proposed that the presence of myoepithelial cells overlying epithelial malignant cell clusters suggests DCIS. However, the recognition of myoepithelial cells in aspirates may be difficult. The aim of this study was to investigate a new nuclear myoepithelial cell marker, p63, a p53 homologue nuclear transcription factor, in a series of breast FNABs in an attempt to distinguish IDC from DCIS.

METHODS

Papanicolaou stained smears from eight cases of pure DCIS and 15 cases of pure IDC with a histologically confirmed diagnosis were submitted to immunocytochemical analysis using the antibody 4A4 against p63. Two pathologists evaluated the presence of p63 positive cells overlying malignant cell clusters and admixed with malignant cells. The frequency of p63 positive cells in DCIS and IDC was compared using Fisher's exact test.

RESULTS

p63 consistently stained the nuclei of myoepithelial cells, either overlying malignant cell clusters and/or admixed with malignant cells. p63 positive myoepithelial cells were seen in all DCIS cases and in nine of the 15 cases of IDC (p = 0.0375). In eight cases (three DCIS and five IDC), scattered p63+ epithelial malignant cells were seen.

CONCLUSIONS

Although p63 positive myoepithelial cells are found more frequently in DCIS cases, their presence cannot be used as a criterion to rule out invasion in breast FNABs because they are present in up to 60% of invasive cases.

Cyclo-oxygenase 2 expression is associated with angiogenesis and lymph node metastasis in human breast cancer

AIMS

Cyclo-oxygenases 1 and 2 (COX-1 and COX-2) are key enzymes in prostaglandin biosynthesis. COX-2 is induced by a wide variety of stimuli, and present during inflammation. COX-2 overexpression has been observed in colon, head and neck, lung, prostate, stomach, and breast cancer. In colon and gastric cancer, COX-2 expression was associated with angiogenesis. The aim of this study was to determine the relation between COX-2 expression and angiogenesis in breast cancer, and to correlate the expression of this enzyme with classic clinicopathological parameters.

METHODS

COX-2 expression was investigated by immunohistochemistry and western blotting analysis. The expression of COX-2 was then related to age, histological grade, nodal status, oestrogen receptor status, p53 expression,c-erb-B2 overexpression, mitotic counts, MIB-1 labelling index, apoptotic index, sialyl-Tn expression, transforming growth factor alpha expression, microvessel density, and disease free survival in 46 patients with invasive ductal breast carcinoma.

RESULTS

By means of immunohistochemistry, COX-2 expression was detected in eight of the 46 carcinomas studied. Western blotting showed COX-2 protein expression in the same breast tumours, but not in normal adjacent tissues. The density of microvessels immunostained with anti-F-VIII related antigen was significantly higher in patients with COX-2 expression than in those without expression (p = 0.03). In addition, COX-2 was significantly associated with the presence of sialyl-Tn expression (p = 0.02), lymph node metastasis (p = 0.03), a high apoptotic index (p = 0.03), and a short disease free survival (p = 0.03) in univariate analyses.

CONCLUSIONS

These data suggest that COX-2 expression is associated with angiogenesis, lymph node metastasis, and apoptosis in human breast cancer. Moreover, these results warrant further studies with larger series of patients to confirm the association with short disease free survival in patients with breast cancer.

Causes of inconsistency in diagnosing and classifying intraductal proliferations of the breast. European Commission Working Group on Breast Screening Pathology

It is now widely recognised that classifying ductal carcinoma in situ (DCIS) of the breast and diagnosing atypical ductal hyperplasia are associated with significant interobserver variation. Two possible reasons for this inconsistency are differences in the interpretation of specified histological features and field selection where morphology is heterogeneous. In order to investigate the relative contribution of these two factors to inconsistent interpretation of intraductal proliferations, histological sections of 32 lesions were sent to 23 European pathologists followed 3 years later by images of small parts of these sections. Kappa statistics for diagnosing hyperplasia of usual type, atypical ductal hyperplasia and ductal carcinoma in situ were 0.54, 0.35 and 0.78 for sections and 0.47, 0.29 and 0.78 for images, respectively, showing that most of the inconsistency is due to differences in morphological interpretation. Improvements can thus be expected only if diagnostic criteria or methodology are changed. In contrast, kappa for classifying DCIS by growth pattern was very low at 0.23 for sections and better at 0.47 for images, reflecting the widely recognised variation in the growth pattern of DCIS. Higher kappa statistics were obtained when any mention of an individual growth pattern was included in that category, thus allowing multiple categories per case; but kappa was still higher for images than sections. Classifying DCIS by nuclear grade gave kappa values of 0.36 for sections and 0.49 for images, indicating that intralesional heterogeneity has hitherto been underestimated as a cause of inconsistency in classifying DCIS by this method. More rigorous assessment of the proportions of the different nuclear grades present could lead to an improvement in consistency.

[Analysis of mutations in the BRCA1 gene in patients with cancer of the breast and/or the ovary in Portugal]

Germline mutations in the BRCA1 gene confer an increased susceptibility to breast and ovarian cancer. Approximately 460 distinct mutations were founded scattered throughout the whole gene. However, several mutations were detected repeatedly in individuals of the same ethnic origin. There are no systematic studies concerning mutations in BRCA1 gene in Portugal. The aim of this study is to identify mutations inh this gene in patients with breast and/or ovarian cancer of Portuguese origin. Thirty-three cases of breast cancer and 3 of ovarian cancer were selected according to early age of onset and family history. Mutation screening of this gene was done by Protein Truncation Test (PTT) and Fragment analysis. Two de novo mutations were identified: 1) A frameshift mutation localised in exon 11 of BRCA1, was identify by the two techniques in an ovarian cancer case. Direct sequential revealed a deletion of 4 nucleotides (3444delAAAT); 2) An alteration in intron 18 (IVS 18 + 80delT) was observed in a breast cancer case. This is probably the first description of mutations in a series of patients with breast and/or cancer in the Portuguese population. The mutations identified in this study have not been previously described in other populations according to the Breast Cancer Information Core web site.

Fine needle aspiration as a tool to establish primary human breast cancer cultures in vitro

OBJECTIVE

To verify the potential role of fine needle aspiration (FNA) cytology in obtaining malignant cells from primary breast cancer for establishment of a primary breast cancer cell line.

STUDY DESIGN

In four patients with primary breast cancer subjected to FNA for diagnostic purposes, we attempted to establish primary cultures. We successfully obtained one primary cell line, originating in micropapillary invasive breast carcinoma. FNA material obtained under sterile conditions was centrifuged, and the cell pellet was washed with Dulbecco Modified Medium. The resulting suspension was seeded in 25-cm2 tissue culture flasks. The flasks were maintained with released caps in a 37 degrees C incubator with a humidified atmosphere of 5% CO2 in air. After one week, cells attached to the bottom of the flasks and began proliferating. When a culture became confluent, the cells were treated with 0.05% trypsin/0.02% EDTA in a PBS solution and subcultured. The flasks were observed daily with an inverted microscope, and culture passages were performed weekly.

RESULTS

The cell line obtained was named I2FPRW and exhibited morphologic and immunohistochemical features of epithelial cells of mammary origin. The cells were positive for cytokeratins (AE1/AE3 and CK 7), EMA and c-erbB-2. At this writing, this cell line was in the 15th passage of subculturing in the flasks with 10% FBS.

CONCLUSION

In the present study we demonstrated that is possible to establish a breast cancer cell line from material obtained by FNA cytology. FNA seems to be a valuable method of obtaining malignant cells from breast cancer able to grow free of fibroblasts in cell cultures.

Consistency achieved by 23 European pathologists from 12 countries in diagnosing breast disease and reporting prognostic features of carcinomas. European Commission Working Group on Breast Screening Pathology

A detailed analysis of the consistency with which pathologists from 12 different European countries diagnose and classify breast disease was undertaken as part of the quality assurance programme of the European Breast Screening Pilot Network funded by the Europe against Cancer Programme. Altogether 107 cases were examined by 23 pathologists in 4 rounds. Kappa statistics for major diagnostic categories were: benign (not otherwise specified) 0.74, atypical ductal hyperplasia (ADH) 0.27, ductal carcinoma in situ (DCIS) 0.87 and invasive carcinoma 0.94. ADH was the majority diagnosis in only 2 cases but was diagnosed by at least 2 participants in another 14, in 9 of which the majority diagnosis was benign (explaining the relatively low kappa for this category). DCIS in 4 (all low nuclear grade) and invasive carcinoma (a solitary 1-mm focus) in 1. The histological features of these cases were extremely variable; although one feature that nearly all shared was the presence of cells with small, uniform, hyperchromatic nuclei and a high nucleo-cytoplasmic ratio. The majority diagnosis was DCIS in 33 cases; kappa for classifying by nuclear grade was 0.38 using three categories and 0.46 when only two (high and other) were used. When ADH was included with low nuclear grade DCIS there was only a slight improvement in kappa. Size measurement of DCIS was less consistent than that of invasive carcinoma. The majority diagnosis was invasive carcinoma in 57 cases, the size of the majority being 100% in 49. The remainder were either special subtypes (adenoid cystic, tubular, colloid, secretory, ductal/medullary) or possible microinvasive carcinomas. Subtyping was most consistent for mucinous (kappa, 0.92) and least consistent for medullary carcinomas (kappa, 0.56). Consistency of grading using the Nottingham method was moderate (kappa=0.53) and consistency of diagnosing vascular invasion, fair (kappa=0.38). There was no tendency for consistency to improve from one round to the next, suggesting that further improvements are unlikely without changes in guidelines or methodology.

Consistency achieved by 23 European pathologists in categorizing ductal carcinoma in situ of the breast using five classifications. European Commission Working Group on Breast Screening Pathology

The increased detection of ductal carcinoma in situ (DCIS) by mammographic screening, the greater use of breast-conserving surgery, and the recognition that certain histological subtypes are associated with a greater risk of local recurrence has led to the formulation of several new classifications of DCIS in recent years. There are, however, no data concerning the degree of consistency with which these schemes can be applied by reasonable numbers of pathologists. Thirty-three cases of DCIS were thus examined by a working group of 23 European pathologists who categorized them using five recently published classifications: (1) that of the European Pathologists' Working Group based on differentiation (a combination of nuclear grade and cell polarization) with categories of poorly, intermediately, and well differentiated; (2) one based entirely on nuclear grade with categories of high, intermediate, and low, currently in use in the UK national and EC-funded breast screening programs; (3) the same classification in which only two categories, high nuclear grade and other, were used; (4) the Van Nuys system in which lesions are divided into high grade, non-high grade with necrosis and non-high grade without necrosis; and (5) a two-category classification based entirely on the presence or absence of comedo necrosis. Of the three systems with three categories, Van Nuys gave the highest overall kappa statistic of 0.42. Others gave similar values of 0.37 and 0.35 showing that assessing cell polarization in addition to nuclear grade neither improves nor worsens consistency. In all three systems, the middle category was associated with the lowest value for kappa. Of the two systems with two categories, that based on nuclear grade gave the highest overall kappa of 0.46 and that based on comedo necrosis the lowest of 0.34. The most robust histological features were thus high- and low-grade nuclei and necrosis as long as the latter did not involve the recognition of a comedo growth pattern. These values probably represent the maximum achievable, at least by reasonable numbers of pathologists in everyday practice. They are better than those previously reported for classification based entirely on architecture, but further improvement is needed.

Expression of sialyl-Tn in fine-needle aspirates from mammographically detected breast lesions: a marker of malignancy?

Malignant transformation is frequently associated with abnormal expression of cell surface carbohydrates. Sialyl-Tn (STn) is a core carbohydrate antigen of tumor-associated mucin formed by the premature 2-6 sialylation of N-acetylgalactosamine. In an attempt to verify whether this antigen is restricted to malignant cells, we studied 30 cases of fine-needle aspiration (FNA) cytology from mammographically detected breast lesions. The rationale for choosing this material was the acknowledged difficulty in diagnosing cytologically small breast lesions, especially epithelial intraductal proliferations. The cases were divided in benign lesions (two fibroadenomas and ten ductal hyperplasias) and malignant lesions (16 ductal carcinomas). Ten of sixteen malignant cases (62.5%) were positive for STn. Five of fourteen benign cases (35.7%) were also positive for STn (two fibroadenomas and three ductal hyperplasias). The most consistent positive results in benign lesions resulted from cases that displayed apocrine metaplasia, although positivity has also been observed in ductal cells without metaplasia. We did not find statistical significant differences among STn expression in benign and malignant breast lesions detected by FNA (P = 0.14). Thus, we conclude that STn is neither specific nor sensitive for detection of malignancy in FNA from mammographically detected breast lesions.

Estimation of estrogen receptor content in fine-needle aspirates from breast cancer using the monoclonal antibody 1D5 and microwave oven processing: correlation with paraffin embedded and frozen sections determinations

We describe a method of immunocytochemically assessing estrogen receptor (ER) status on alcohol-fixed smears obtained by fine-needle aspiration (FNA) from breast cancer patients, using a commercially available monoclonal antibody (1D5) with microwave oven processing. A series of 31 cases of aspirates from breast cancer were analysed and the results were compared with assessment by ER immunocytochemical assay using the same procedure on formalin-fixed tissue and with assessment by ER-ICA assay on frozen sections. The results were scored semiquantitatively using a five grade scoring system. Of the 31 cases examined, 21 were positive at least by two methods and 10 were negative for all three determinations. The results obtained in the ER immunocytochemical assay on aspirates and paraffin-sections using the antibody 1D5 and those obtained on frozen sections using the antibody H222 were closely similar. In only one case was it not possible to interpret the reaction in the cytological specimen because there was a strong background in the smear. In general, we obtained more intense positivity with the antibody 1D5 in aspirates and formalin-fixed material than with the antibody H222 in frozen sections. The scoring results of the three methods were almost identical. We conclude that the application of ER method on alcohol-fixed smears will eliminate the need for using a special fixation procedure and will provide several advantages, such as: improvement in morphological concomitant analysis, utilization whenever malignancy is found without necessity to re-aspirate the patient, and adequacy of archival material.

Diagnosis of sputum smear-negative forms of pulmonary tuberculosis by transthoracic fine-needle aspiration

We reviewed 25 patients submitted to transthoracic fine-needle aspiration (TFNA) who had a final diagnosis of pulmonary tuberculosis. In all cases, bacteriological stains and cultures of sputum and bronchial washing had been performed before admission and were negative. According to the material obtained from the procedure, the aspirates were divided in three groups: diagnostic (Ziehl-Neelsen and/or culture positive, n = 8, 32%), suggestive (granulomatous inflammatory changes, n = 10, 40%) and inconclusive (nonspecific inflammatory changes, isolated giant cells and/or blood, n = 7, 28%). On chest X-ray, 12 patients had opacities with the greatest diameter not exceeding 4 cm. All aspirates in the diagnostic group were from patients with this type of lesion, while all the inconclusive aspirates belonged to patients with larger lesions. As complications, 1 patient needed thoracic drainage for pneumothorax and 3 patients had haemoptyses. Thus TFNA has a place in the diagnosis of suspected pulmonary tuberculosis when more simple methods have failed, and its effectiveness seems to be increased when the lesions do not exceed 4 cm in diameter.