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

Abstract

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.

Detection of breast cancer metastasis in sentinel lymph nodes using intra-operative real time GeneSearch™ BLN Assay in the operating room: results of the Cardiff study

“…However, conventional histology has inherent sampling error and therefore it should be noted that the sensitivity of the reference 'gold standard' is less than 100%. The false negative rate of conventional histology depends on the protocol followed for pathological examination of SLNs which varies considerably throughout Europe and can be reduced by serial sections and IHC [9].…”

The value of immunohistochemistry in sentinel lymph node histopathology in breast cancer

“…Although SLNB has recently been incorporated into the TNM classification (Sobin et al, 2002), the optimal histopathological workup of SLNs is currently not standardised. A recent survey of practices in a large number of European institutions revealed wide discrepancies internationally as well as nationally (Cserni et al, 2004a). Although some countries have set up national guidelines for specimen handling, many institutions have developed their own guidelines for SLN processing, which are more intensive than the national guidelines recommend as a minimum, and which are frequently determined by the institution's research strategy.…”

The clinical significance of sentinel lymph node micrometastasis in breast cancer

“…The most effective technique for assessing the SLN will depend on the nature of the lesion that needs to be identified, hence decisions need to be made about the necessity of identifying MM and ITC [12]. Cserni et al [73] has demonstrated discrepancies in the current practice of SLN evaluation, in addition to inconsistency regarding the categorization of MM amongst pathologists presented with identical digital images. As HES is increasingly complemented by IHC and molecular amplification techniques, including PCR and RT-PCR, subgroups of patients will be identified in which MM are only detectable by one modality or the other.…”