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.

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.

Consequences of a National Mammography Screening Program on diagnostic procedures and tumor sizes in breast cancer. A retrospective study of 1540 cases diagnosed and histologically confirmed between 1995 and 1997.

In 1992, a national screening mammography program, including female patients between 50 and 64 years of age, was launched in Luxembourg. The effects of this campaign on the different diagnostic procedures, especially fine needle aspirations (FNA), large core needle biopsies (LCNB), and surgical specimens, were analyzed. From 1983 to 1997, the National Cancer Registry recorded 3167 new cases of invasive female breast cancer, all histologically diagnosed in one central pathology department. In 1996, the population consisted of 418,300 inhabitants (212,900 females). The number of breast cancer, tumor size, the nature of the diagnostic procedures, their diagnostic value as well as the number of physicians, "aspirators", and "biopsists" were evaluated. Between 1992 and 1994, the incidence of invasive breast cancers increased, concomitant with the launching of a National Screening Mammography Program. The diagnosis of in situ cancers tripled, and the mean size of invasive breast cancer decreased from 2.1-2.4 cm to 1.1-1.4 cm. Since 1994, the number of FNA had remained stable, LCNB had increased by 417.5%, and surgical biopsies had decreased by 18.95%. Between 1995 and 1997, 28.37% of 1075 FNA, and only 9.6% of 465 LCNB yielded inadequate samples. FNA were done by 77 different doctors (53.25% being gynecologists) and LCNB by 34 (52.94% being radiologists). The first diagnoses of all invasive cancers (n = 790) were made by using frozen sections from surgical specimens in 58.35% (n = 461), LCNB in 18.23% (n = 144), mastectomy in 10.13% (n = 80), formalin-fixed biopsies in 9.49% (n = 75), and FNA in 3.17% (n = 25). There are beneficial effects (increase in the number of diagnoses of in situ cancer; decrease in tumor sizes) not only for the "target" age group (50-64 years), but also for all female age groups (> 15 years). For quality assurance purposes, it is absolutely recommended to carry out pathological, radiological, and diagnostic work in specialized centers.

[Detection of glial fibrillary acidic protein in central nervous tumors using an immunohistochemical method. Preliminary study of 33 cases (author's transl)]. / Le diagnostic des tumeurs nerveuses centrales par un marqueur de la protéine gliofibrillaire acide. Etude préliminaire d'une série de 33 cas.

Thirty-two cases of human central nervous tumor and one experimental glioma were studied in fixed paraffin or epon embedded tissues using the peroxidase-antiperoxidase method. The present study confirms the usefulness of immunohistochemical methods for the diagnostic evaluation of neuro-epithelial neoplasms. The authors also include some prognostic and histogenetic comments about glial tumors.

Accuracy of frozen section diagnoses of breast lesions after introduction of a national programme in mammographic screening.

AIMS: By introducing mammography screening programmes, the size of the detected breast lesions became smaller and the histopathological interpretation problems greater. The study's aim was to analyse the risks and possible limitations of the frozen section method. METHODS AND RESULTS: Frozen section consultations of breast lesions (n=559) 2 years before and 6 years after launching a national mammographic screening programme in 1992 were evaluated in regard of the benign/malignant ratio, tumour size, preoperative frozen section results and final permanent section diagnoses. The breast frozen section examinations of 1990 compared with those from 1998 declined from 70.7% (299/423) to 62.2% (260/418) (P < 0.01), the benign/malignant ratio from 1.09 to 0.54 (P < 0.0001), the rate of the conclusive, correct frozen section diagnoses from 96.3% to 91.9% (P < 0.03). The sensitivity dropped from 92.3% to 87.6%, the negative predictive value from 95.7% to 88.3%, whereas the negative likelihood ratio rose from 0.08 to 0.12. The 'small' (< or = 10 mm) invasive breast carcinomas increased from 14.2% to 22.3% (P < 0.01) and the 'in situ' carcinomas from 2.1% to 6.6% (P < 0.05). CONCLUSIONS: The declining sizes of breast tumours (< or = 10 mm), especially from radiologically detected lesions and sometimes without a macroscopic correlate, create new limitations and changing indications in the histopathological interpretation. Considering the performance of new diagnostic methods (i.e. large core needle biopsies), frozen sections of surgical specimens should not be the primary diagnostic procedure for breast lesions and should be performed only after other preoperative methods have failed.