Pleomorphic LCIS what do we know? A UK multicenter audit of pleomorphic lobular carcinoma in situ.

AIMS: Pleomorphic lobular carcinoma in situ (PLCIS) is a relatively newly described pathological lesion that is distinguished from classical LCIS by its large pleomorphic nuclei. The lesion is uncommon and its appropriate management has been debated. The aim of this study is to review data from a large series of PLCIS to examine its natural history in order to guide management plans. MATERIALS AND METHODS: Comprehensive pathology data were collected from two cohorts; one from a UK multicentre audit and the other a series of PLCIS cases identified from within the GLACIER study cohort. 179 cases were identified of whom 176 had enough data for analysis. RESULTS: Out of these 176 cases, 130 had invasive disease associated with PLCIS, the majority being of lobular type (classical and/or pleomorphic). A high incidence of histological grade 2 and 3 invasive cancers was noted with a predominance of ER positive and HER-2 negative malignancy. When PLCIS was the most significant finding on diagnostic biopsy the upgrade to invasive disease on excision was 31.8%, which is higher than pooled data for classical LCIS and DCIS. CONCLUSION: The older age at presentation, high grade of upgrade to invasive cancer, common association with higher grade tumours suggest that PLCIS is an aggressive form of insitu disease. These findings support the view that PLCIS is a more aggressive form of lobular in situ neoplasia and supports the tendency to treat akin to DCIS.

Accuracy of classification of invasive lobular carcinoma on needle core biopsy of the breast.

Although the UK National Institute for Health and Care Excellence guidelines recommend that in patients with biopsy-proven invasive lobular carcinoma (ILC), preoperative MRI scan is considered, the accuracy of diagnosis of ILC in core biopsy of the breast has not been previously investigated. Eleven pathology laboratories from the UK and Ireland submitted data on 1112 cases interpreted as showing features of ILC, or mixed ILC and IDC/no special type (NST)/other tumour type, on needle core biopsy through retrieval of histology reports. Of the total 1112 cases, 844 were shown to be pure ILC on surgical excision, 154 were mixed ILC plus another type (invariably ductal/NST) and 113 were shown to be ductal/NST. Of those lesions categorised as pure ILC on core, 93% had an element of ILC correctly identified in the core biopsy sample and could be considered concordant. Of cores diagnosed as mixed ILC plus another type on core, complete agreement between core and excision was 46%, with 27% cases of pure ILC, whilst 26% non-concordant. These data indicate that there is not a large excess of expensive MRIs being performed as a result of miscategorisation histologically.

Updated UK Recommendations for HER2 assessment in breast cancer.

Human epidermal growth factor receptor 2 (HER2) overexpression is present in approximately 15% of early invasive breast cancers, and is an important predictive and prognostic marker. The substantial benefits achieved with anti-HER2 targeted therapies in patients with HER2-positive breast cancer have emphasised the need for accurate assessment of HER2 status. Current data indicate that HER2 test accuracy improved following previous publication of guidelines and the implementation of an external quality assessment scheme with a decline in false-positive and false-negative rates. This paper provides an update of the guidelines for HER2 testing in the UK. The aim is to further improve the analytical validity and clinical utility of HER2 testing by providing guidelines of test performance parameters, and recommendations on the postanalytical interpretation of test results. HER2 status should be determined in all newly diagnosed and recurrent breast cancers. Testing involves immunohistochemistry with >10% complete strong membrane staining defining a positive status. In situ hybridisation, either fluorescent or bright field chromogenic, is used either upfront or in immunohistochemistry borderline cases to detect the presence of HER2 gene amplification. Situations where repeat HER2 testing is advised are outlined and the impact of genetic heterogeneity is discussed. Strict quality control and external quality assurance of validated assays are essential. Testing laboratories should perform ongoing competency assessment and proficiency tests and ensure the reliability and accuracy of the assay. Pathologists, oncologists and surgeons involved in test interpretation and clinical use should adhere to published guidelines and maintain accurate performance and consistent interpretation of test results.

Conservative management of screen-detected radial scars: role of mammotome excision.

AIMS: Traditionally, a core biopsy diagnosis of radial scar will prompt diagnostic surgery because of the risk of associated malignancy. However, in the absence of atypia, the risk of malignancy is low. The recent introduction of the mammotome device facilitates vacuum-assisted large-volume sampling of a lesion, such that a benign diagnosis may be accepted more confidently, and if the lesion has been entirely removed, it effectively becomes a therapeutic procedure. The aim of this study was to review the role of mammotome excision in the management of non-atypical radial scars in the screening population. METHODS: Screen-detected radial scars diagnosed on core biopsy between July 2004 and September 2008 were identified from pathology records. From January 2006, the mammotome device was used to excise non-atypical radial scars on core biopsy, as an alternative to surgery. RESULTS: 22 core biopsy samples containing radial scars without atypia were included in the study; 14 were planned for mammotome excision and eight for diagnostic surgical excision. In the mammotome group, 78% (11/14) of patients had confirmation of non-atypical radial scars and thus avoided an operation. Three of the 14 cases planned for mammotome excision required surgery; in one case, the mammotome cores contained lobular in situ neoplasia, and, in two cases, attempts to sample the lesion with the mammotome were unsuccessful. Only one of the 22 cases ultimately proved malignant. This was a case of ductal carcinoma in situ arising within a radial scar, where the patient proceeded straight to surgery in view of discordance between radiological and pathological features. CONCLUSION: Utilisation of mammotome excision in the management of non-atypical radial scars successfully avoided surgery in 78% of eligible patients. Pathologists have an important role in selecting patients for mammotome excision by excluding the presence of atypia.

Screen-detected pleomorphic lobular carcinoma in situ (PLCIS): risk of concurrent invasive malignancy following a core biopsy diagnosis.

AIMS: Pleomorphic lobular carcinoma in situ (PLCIS) is an uncommon, recently recognized variant of lobular carcinoma in situ (LCIS). Its natural history, biological behaviour and clinical characteristics are uncertain. The aim was to review the radiological and pathological findings in a series of screen-detected PLCIS diagnosed on needle core biopsy with a view to determining the diagnostic features, immunohistological profile and risk of concurrent invasive malignancy. METHODS AND RESULTS: Ten cases of core biopsy-diagnosed, screen-detected PLCIS were identified. Core biopsy findings were compared with pathological findings at subsequent surgery. Two cases were associated with possible microinvasion on the core. Two of 10 had invasive lobular carcinoma and one had microinvasive lobular carcinoma on subsequent surgical excision (positive predictive value for malignancy = 30%). There was associated conventional LCIS on either core or excision biopsy in all cases except one. All three cases of oestrogen receptor (ER)-negative PLCIS arose in the context of ER+ conventional LCIS. CONCLUSIONS: PLCIS is a potentially more aggressive lesion than conventional LCIS and may present as mammographic calcification through a breast screening programme. Diagnosis may be problematic and immunohistochemical markers including ER may prove a useful diagnostic adjunct. There is a significant risk of concurrent invasive carcinoma following a core biopsy diagnosis.

A multi-centre investigation towards reaching a consensus on the immunohistochemical detection of ERbeta in archival formalin-fixed paraffin embedded human breast tissue.

Estrogen receptor (ER) alpha is a well-established independent prognostic factor in breast cancer whose presence determines the clinical implications of adjuvant endocrine therapy. A second receptor, ERb has been described, and a number of studies have examined its expression in breast tissue. However elucidation of the role played by ERb has been hampered by published immunohistochemical studies employing a variety of protocols and scoring systems such that inter-laboratory comparisons are difficult. Here we present a multi-centre study designed to critically evaluate inter-laboratory differences in methodology. Six UK and Irish centres participated in this study. A small series of breast cancers were stained using centre-specific laboratory protocols and scored using both centrespecific and standard scoring protocols. There was generally poor agreement as to what constituted a positive or negative case when centre-specific scoring systems were used with less than half of all cases in agreement. Concordance was improved when a standard scoring system was used but varied according to threshold for positivity employed and primary antibody. Our results emphasise the need for further studies addressing the role of ERb to be based on a wider consensus on criteria for positivity. Ideally this should be based on calibration against clinical outcome.

Oestrogen receptor beta: what it means for patients with breast cancer.

Oestrogen receptor (ER) alpha is a well established prognostic marker in breast cancer, and all patients who are ER alpha positive receive tamoxifen as adjuvant endocrine therapy. Although ER alpha predicts a favourable disease outcome, the usefulness of ER beta as a clinical prognostic marker remains to be defined. Here, we outline the history of both ERs and discuss the implications ER beta has to patients with breast cancer.

Reduced expression of oestrogen receptor beta in invasive breast cancer and its re-expression using DNA methyl transferase inhibitors in a cell line model.

To gain insights into the possible role of oestrogen receptor (ER) beta in breast carcinogenesis, immunohistochemical analysis of ER beta was performed on 512 breast specimens encompassing normal (n = 138), pure ductal carcinoma in situ (n = 16), invasive cancers (n = 319), lymph node metastases (n = 31), and recurrences (n = 8). Real-time polymerase chain reaction (PCR) was used to investigate the methylation status of the ER beta gene in the ER beta negative breast cancer cell lines SkBr3 and MDA-MB-435. A gradual reduction in, but not a complete loss of, ER beta expression was observed during the transition from normal and pre-invasive lesions to invasive cancers, where ER beta was lost in 21% of cases. This was more pronounced in invasive ductal than in lobular carcinomas, a significantly higher proportion of which were ER beta-positive (74% compared with 91%, respectively, p = 0.0004). Examination of paired primary cancers with their axillary lymph node metastases showed that if ER beta was present in the primary tumour, it persisted in the metastasis. Treatment of ER beta-negative cell lines with DNA methyl transferase inhibitors restored ER beta expression, providing experimental evidence that silencing of ER beta in breast carcinomas could be due to promoter hypermethylation. These results suggest that loss of ER beta expression is one of the hallmarks of breast carcinogenesis and that it may be a reversible process involving methylation.