Pathological evaluation of the staging axillary lymph nodes for breast cancer: a national survey in the United Kingdom.

AIMS: The handling and examination of sentinel lymph nodes (SLNs) to detect metastasis is critical in the assessment of early breast cancer patients. This survey investigates the variation in practise followed by pathology units across the United Kingdom in the staging evaluation of axillary lymph nodes (ALNs). METHODS AND RESULTS: A structured questionnaire, approved by the National Health Service Breast Screening Programme pathology Big 18 committee, was circulated among all pathologists. There were 160 respondents; 92% performed SLN biopsy for staging, 97% had a protocol for processing SLNs and most laboratories examined the ALNs using formalin-fixed, paraffin-embedded (FFPE) samples (85.6%). A few used PCR (7.5%), frozen section (3.8%) or touch imprint cytology (3.1%), with or without subsequent FFPE section examination. Currently, 33% perform serial sectioning, with the majority of the rest (75%) staining three levels using H&E. Most units (85%) undertook immunohistochemistry evaluation only when suspicious cells were detected on H&E-stained sections. CONCLUSIONS: The range of practise in UK histopathology departments is described with regard to the dissection and evaluation of ALNs/SLN biopsy. The variation in practise was not very marked and most departments adhered to national guidelines. Any UK study seeking to relate ALN status and outcome would need to be mindful of the variability in nodal processing and examination.

Management of palpable but radiologically occult breast abnormalities.

OBJECTIVE: To examine the utility of palpation-guided fine-needle aspiration cytology (pgFNAC) in the context of clinically palpable but radiologically occult breast abnormalities in this era of digital mammography and high sensitivity ultrasound. METHODS: Women undergoing pgFNAC from January 2005 to December 2007 were identified from the histopathology database and correlated with clinical and radiological findings recorded prospectively in electronic patient records. RESULTS: 142 cases matching our selection criteria were identified with a mean age of 43 (SD ±13.7) years; 83 patients had focal lumps and 59 had non-focal lumpiness. In the latter, pgFNAC showed C1 cytology in 45 (76.3%), C2 in 13 (22%) and C3 in 1 (1.7%) patient. In 83 patients with a focal discrete lump, pgFNAC revealed C1 cytology in 65 (78.3%), C2 in 14 (16.9%), and 2 patients each had C3 and C4 cytology. Core biopsy was undertaken in the latter 4 patients, invasive cancer was found in 1 patient each with C3 and C4 cytology and benign pathology in the rest. To date, none of the patients discharged has developed pre-malignant or malignant lesions in the ipsilateral breast. CONCLUSION: In patients presenting with clinically palpable but radiologically occult breast abnormality, pgFNAC can identify those who need further investigation or who can be safely discharged.

Pattern of expression of genes linked to epigenetic silencing in human breast cancer.

Epigenetic mechanisms such as DNA methylation are now recognized to play an important role in neoplasia. The aim of this study is to relate the pattern of expression of multiple cancer genes known to undergo epigenetic inactivation by promoter hypermethylation in breast cancer with histologic and outcome data. We used immunohistochemistry to study expression of the tumor suppressor gene p16, estrogen receptor (ER) alpha, ERbeta, progesterone receptor (PR), and the DNA repair gene MGMT (O6 -methylguanine-DNA methyltransferase) in a panel of 200 breast cancers. Methylation-specific polymerase chain reaction was used to confirm MGMT promoter methylation. Loss of expression of MGMT, ERalpha, ERbeta, PR, and p16 was observed in 19%, 24%, 13%, 40%, and 50% of cases, respectively. A significant correlation was seen between grade III tumor and loss of expression of ERalpha, ERbeta, PR (all P < .0001), and MGMT (P = .04), whereas loss of expression of p16 was associated with grades I and II tumors (P < .001). Cases that expressed 3 or less of the 5 proteins studied had significantly reduced survival (P = .0016). Methylation-specific polymerase chain reaction in a subset of 20 cancers showed DNA methylation associated with the loss of MGMT expression (P < .001). In conclusion, there is silencing of several key genes in breast cancer affecting molecular pathways involved in cell immortalization, DNA repair, and hormonal regulation, and this correlates significantly with risk of cancer-specific death. This expression profile could be linked to epigenetic events, and if so, these pathways have potential as targets for therapeutic strategies based on reversal of epigenetic silencing.

Residual mucin and response after neoadjuvant chemotherapy (NAC) in breast cancer.

Neoadjuvant chemotherapy (NAC) is the standard of care for patients with breast cancer with inoperable disease or smaller tumours who might benefit from a conservative surgery after downstaging of their disease. Nevertheless, evidence shows that preoperative and postoperative chemotherapy are equivalent in terms of long-term survival. Response and histological changes after NAC have been widely studied in invasive ductal carcinoma not otherwise specified, but there is a paucity of characterisation of patterns of response to chemotherapy in less frequent histological types. We report extensive residual mucin deposits after chemotherapy in a woman with locally advanced breast cancer and a prominent mucinous component at diagnosis. Interestingly, residual mucin was co-located with the initial tumour, in the breast as well as in the axillary lymph nodes. The distribution of mucin may be a valuable marker of the extent of mucinous carcinomas prior to NAC.

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.

The practicalities of using tissue slices as preclinical organotypic breast cancer models.

Models considering breast cancer complexity cannot be easily or accurately replicated in routine cell line or animal models. We aimed to evaluate the practicality of organotypic tissue slice culture in breast cancer. Following ethical approval, 250 µm thick sections from surplus breast tumours (n=10) were prepared using a vibrating blade microtome. Triplicate tissue slices were placed in 6-well plates and cultured for up to 7 days ± tamoxifen (1 nM) or doxorubicin (1 µM). Tissue slices were fixed and embedded before sectioning for morphological evaluation and immunohistochemistry. H&E showed good preservation of tissue morphology. Collagen production was evident. Biomarkers of proliferation and apoptosis could be evaluated using immunohistochemistry and used as surrogates to quantify drug effects. In summary, breast cancer tissue slices can be cultured in vitro as organotypic models. Nevertheless, although simple in concept, the delicacy of the model with regard to handling makes subsequent analytical processes challenging.

Regulation of estrogen receptor ß1 expression in breast cancer by epigenetic modification of the 5' regulatory region.

ERß1 is often down-regulated in breast cancer compared to normal breast but mechanisms surrounding this are unclear. We examined whether loss of heterozygosity (LOH) or methylation at ERß promoters (0N, 0K) and/or untranslated exon 0N were involved in ERß down-regulation in breast cancer tissues and cell lines and if treatment with the de-methylating agent 5-aza-deoxycytidine and/or the histone deacetylase inhibitor Trichostatin A could influence expression in vitro. We found no evidence of correlation between LOH at 14q22-24 (genomic locus containing ERß/ESR2), and ERß1 expression in primary breast cancers. A negative correlation between ERß1 mRNA expression and methylation status was observed for promoter 0N in BT-20, MDA-MB-453 and T47D cells. Promoter 0K was consistently unmethylated. In primary breast tumours, methylation of the untranslated exon 0N, downstream of promoter 0N, but not of promoter 0N itself, correlated with down-regulation of ERß. In MDA-MB-453 cells, treatment with 5-aza-deoxycytidine was sufficient to induce ERß1 expression from the 0N promoter while in BT-20 both agents were required. Examination of various sites on ESR2 highlighted epigenetic but not genetic regulation of ERß1. In particular methylation adjacent to promoter 0N was a key regulatory event for ERß1 silencing. A combination of de-methylating agents and histone deacetylase inhibitors fully restored ERß1 expression which may offer a novel therapeutic angle for breast cancer management.

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.