Profiling differential microRNA expression between in situ, infiltrative and lympho-vascular space invasive breast cancer: a pilot study.

Ductal carcinoma in situ (DCIS), invasive breast cancer (IBC) and lympho-vascular invasion (LVI) represent distinct stages in breast cancer progression with different clinical implications. Altered microRNA (miRNA) expression may play a role in mediating the progression of DCIS to IBC and LVI. The aim of this pilot study was to investigate whether differential miRNA expression could play a role in breast cancer progression. Cancer cells from DCIS, IBC and LVI were microdissected from formalin fixed paraffin embedded (FFPE) tissue of five breast cancer samples. MiRNA profiling of extracted RNA was performed using the TaqMan® Array Human MicroRNA Cards A and B v3.0. Candidate miRNAs and gene targets were validated by qPCR. 3D culture of MCF10A, MCF10DCIS.com and T47D cells were used as models for normal, DCIS and IBC. Immunohistochemistry of candidate genes was performed on FFPE 3D cell cultures as well as on tissue microarray which included cores of DCIS and IBC samples. MiR-150, miR-126 and miR-155 were found to be more highly expressed in IBC and LVI compared to DCIS. Gene targets of these miRNAs, RhoA, PEG10 and MYB, were found to be more highly expressed in DCIS compared to IBC by qPCR and in MCF10A and MCF10DCIS.com cells compared to T47D cells by immunohistochemistry. There was no difference in intensity of staining of RhoA by immunohistochemistry in DCIS versus IBC samples on tissue microarray. In this pilot study, we found evidence to support a potential role for variation in miRNA levels in the transition from DCIS to IBC.

Embedding continuous quality improvement processes in multidisciplinary teams in cancer care: exploring the boundaries between quality and implementation science.

Objective The aim of the present study was to identify key enabling factors for engaging multidisciplinary teams (MDTs) in cancer care across the spectrum of translational research and quality improvement (QI) projects. Methods The study was conducted in two large Sydney metropolitan hospitals. Qualitative methods, including structured observations of MDT meetings and semi-structured interviews with MDT leaders and champions, were used to identify how teams interact with and generate research and implementation initiatives. Enabling factors for and barriers to the engagement of MDTs in translational research and QI were identified. Results Four key enabling factors emerged from the analysis of data generated from observing 43 MDT meetings and 18 semi-structured interviews: (1) access to high-quality data around individual and team performance; (2) research-active team leaders; (3) having experts, such as implementation scientists, embedded into teams; and (4) having dedicated research or QI-focused meetings. Barriers included a lack of time, administrative support, research expertise and access to real-time data. Conclusions The identification of enabling factors for and barriers to translational research and QI provides evidence for how multidisciplinary cancer care teams may best be engaged in research and QI that aims to improve service and care outcomes. What is known about the topic? MDTs are key to the delivery of cancer care in Australia, but there is scant research into how teams can best be engaged in translating research from basic science through to implementation science and QI. What does this paper add? This paper provides new evidence from an immersive study of cancer care MDTs in two large metropolitan hospitals in Sydney (NSW, Australia), regarding the key enabling factors for and barriers to successful engagement in translational research and QI in cancer care. What are the implications for practitioners? Cancer care professionals in MDTs are presented with an opportunity to embed translational research and QI into cancer care. MDTs can operate as an ideal vehicle to look beyond individual patient outcomes to broader trends and population health outcomes.

The prognostic value of Ki67 in systemically untreated patients with node-negative breast cancer.

AIM: To evaluate the utility of Ki67 as a prognostic marker in a series of patients with node-negative breast cancer untreated with adjuvant systemic therapy. METHODS: The cohort consisted of 203 cases treated with breast conserving surgery and radiation only; median follow-up was 183 months (range 156-277 months). An immunohistochemical panel of oestrogen receptor (ER), progesterone receptor (PR), cytokeratin (CK)5/6 and Ki67 and human epidermal growth factor 2 in situ hybridization (HER2-ISH) was performed on the tumour samples. Ki67 scores were evaluable in 193/203 patients (95.1%). The primary outcome was breast cancer specific survival (BCSS). RESULTS: Of the cohort, 29 (14.2%) died of breast cancer. A cut off of 10% separated tumours into a 'Ki67-low' (n=70) or 'Ki67-high' group (n=123). The breast cancer specific survival was 97.1% and 77.6% for Ki67-low and Ki67-high groups, respectively. Univariate analysis showed that in this lymph node-negative cohort, the predictors for BCSS were tumour size, Ki67, LVI, age and histological grade 3. Multivariable analysis showed that Ki67 index and lymphovascular space invasion were independent predictors of breast cancer death. To examine the utility of Ki67 in assignment of immunohistochemically molecular subtypes, cases were assigned into Luminal A (ER-positive, HER2-negative, Ki67 ≤14%), Luminal B (ER-positive, HER2-negative, Ki67 >14%) and triple negative (ER/PR-negative and HER2-negative, any Ki67). The 15-year breast cancer specific survival was 91.7%, 79.4% and 75.8%, respectively. CONCLUSIONS: A statistically significant difference in breast cancer specific survival is seen in groups defined using Ki67 and receptor status, whereas histological grading was not a significant predictor of survival. Ki67 immunostaining provides prognostic information beyond traditionally assessed clinicopathological variables.

Prohibitin expression is associated with high grade breast cancer but is not a driver of amplification at 17q21.33.

AIMS: In a study of ductal carcinoma in situ of the breast, we identified five genes at chromosome 17q21.33 that were over-expressed in high grade cases, and showed a correlation between expression and gene copy number. The aim of this study was to investigate potential drivers of genomic amplification at 17q21.33. METHODS: Analysis of high resolution comparative genomic hybridisation and published data specified a minimum region of amplification at 17q21.33. Prohibitin (PHB) expression was examined by immunohistochemistry in 285 invasive breast cancers. Gene copy number was examined by fluorescence in situ hybridisation. RESULTS: The minimum region of amplification at 17q21.33 included ten genes with PHB selected as a candidate driver. Increased PHB expression was associated with higher grade breast cancer and poorer survival. Amplification of PHB was detected in 13 of 235 cases (5.5%) but was not associated with PHB expression. PHB amplification was most common in the ERBB2+ breast cancer subtype, although high expression was most prevalent in basal-like and luminal B cancers. CONCLUSIONS: Amplification at 17q21.33 is a recurrent feature of breast cancer that forms part of a 'firestorm' pattern of genomic aberration. PHB is not a driver of amplification, however PHB may contribute to high grade breast cancer.

Characteristics of HER2-positive breast cancer diagnosed following the introduction of universal HER2 testing.

The aim of this study was to determine the impact of universal HER2 testing on the clinico-pathologic profile of HER2+ breast cancer. Data were extracted from breast cancer pathology reports spanning two periods: before (2003/4, n = 379), and after (2008/9, n = 560) the introduction of universal testing. In 2003/4, 43.3% of breast cancers were tested for HER2 with 16% of tested cases HER2+. In 2008/9, 98.4% of cases were tested with 14.7% HER2+. In 2008/9, HER2+ status was associated with younger age, higher grade, increased tumour size, lymph node involvement, negative oestrogen and/or progesterone receptor status. HER2+ cases diagnosed in 2003/4 were not significantly different in respect of these features. The rate of HER2+ breast cancer amongst screen detected cases in 2008/9 was 8.3%. The phenotype of HER2+ breast cancer was stable following the introduction of universal testing. The overall rate of HER2+ breast cancer was influenced by screen detection.

Familial concordance of breast cancer pathology as an indicator of genotype in multiple-case families.

The heterogeneity of multiple case breast cancer families that do not carry mutations in BRCA1 or BRCA2 (non-BRCA1/2 families) poses a challenge to the identification of breast cancer susceptibility genes. The aim of this study was to determine whether intrafamilial concordance in breast cancer pathology could identify subgroups of non-BRCA1/2 families with consistent genotypic features. Invasive breast cancers were reviewed from 84 individuals belonging to 30 multiple-case families; BRCA1 (n = 9), BRCA2 (n = 10), and non-BRCA1/2 (n = 11). Hierarchical cluster analysis based on histopathology and age at first diagnosis was then used to specify three subgroups designated Clusters 1-3. The genomic features of non-BRCA1/2 families were examined by genome wide linkage and FGFR2 SNP genotyping, according to whether they showed cluster-concordant or cluster-mixed familial pathology. The majority of pathogenic BRCA1 mutation carriers (80%) fell into a single cluster. In contrast pathogenic BRCA2 mutation carriers were distributed across all three clusters and within families, cluster groups were also generally mixed. Most non-BRCA1/2 mutation carriers belonged to Cluster 3 (71%). Genome wide linkage data from five non-BRCA1/2 Cluster 3-concordant families were compared with four mixed cluster non-BRCA1/2 families. This revealed a number of distinct linkage peaks, including some regions previously associated with breast cancer susceptibility. The distribution of low risk alleles in FGFR2 was not different between these two subgroups (P = 0.237). The pattern of breast cancer pathology concordance amongst family members may assist the investigation of breast cancer susceptibility in multiple case families.

Diagnostic evaluation of papillary lesions of the breast on core biopsy.

The management of asymptomatic intraductal papillary lesions of the breast diagnosed on core biopsy poses a challenge for patients and clinicians, as the distinction between common benign lesions and atypical or malignant varieties may be difficult without formal excision. The aim of this study was to determine whether a combination of histopathologic and biomarker features could be used to accurately identify benign papillary lesions on core biopsy. An inclusive group of 127 excised papillary lesions was characterized by detailed histopathologic review and immunohistochemical staining for the basal markers cytokeratin 5/6 (CK5/6) and P63 and the proliferation marker Ki67. Comparison of benign, atypical, and malignant lesions revealed that the combination of broad, sclerotic fibrovascular cores, and epithelial CK5/6 staining was most commonly seen in benign papillomas. Ki67 staining revealed striking intralesional heterogeneity, but there was no difference between the high scores of benign, atypical, or malignant lesions (P=0.173). In a non-overlapping set of 42 cases, a binary classifier specifying benign lesions on the basis of thick fibrovascular cores and epithelial CK5/6 staining on core biopsy gave an overall misclassification rate of 4/42 (10%) when compared with the final excision diagnosis. Misclassified cases included 2/27 lesions ultimately diagnosed as benign and 2/2 atypical papillomas. All malignant lesions (n=13) were correctly assigned. The combined assessment of fibrovascular core thickness and CK5/6 staining on core biopsy distinguished benign from malignant papillary lesions, but did not separate benign from atypical cases. This approach may form a useful addition to the clinicopathologic evaluation of papillary lesions of the breast.

A class discovery and class prediction approach to histopathological classification of mammographic screen detected columnar cell lesions of the breast.

AIMS: Columnar cell lesions (CCLs) of the breast have been increasingly recognised in biopsies taken to investigate mammographic screen detected microcalcification. The aim of this study was to identify distinct CCL subtypes by systematic analysis of histopathology. METHODS: Hierarchical cluster analysis was performed based on the profile of histopathological features in 102 screen detected CCLs. Features assessed included nuclear morphology, acinar dilatation, epithelial cell hyperplasia, cell crowding, apical snout formation and intraluminal secretion. The stability of this classification was tested in an independent cohort of 32 cases. RESULTS: The histopathology of screen detected CCLs was extremely variable. Hierarchical cluster analysis identified two subclasses: Class 1 (34/102, 33%) characterised by absence of nuclear atypia and less pronounced hyperplasia; and Class 2 (68/102, 67%) that were generally more atypical. Ki-67 scores were significantly lower for Class 1 CCLs (p < 0.001). In the independent cohort of 32 cases, Class 1 cases were clearly distinguished from Class 2, indicating that these were stable phenotypes amongst screen detected CCLs. CONCLUSIONS: The histopathological features of CCLs diagnosed at screening are extremely heterogeneous. Using a systematic approach, we have devised a broad classification system that delineates a category of less atypical CCLs that could form a basis for future studies.

Poor-prognosis estrogen receptor-positive breast cancer identified by histopathologic subclassification.

PURPOSE: Identification of biologically and clinically distinct breast cancer subtypes could improve prognostic assessment of primary tumors. The characteristics of "molecular" breast cancer subtypes suggest that routinely assessed histopathologic features in combination with limited biomarkers may provide an informative classification for routine use. EXPERIMENTAL DESIGN: Hierarchical cluster analysis based on components of histopathologic grade (tubule formation, nuclear pleomorphism, and mitotic score), expression of ER, cytokeratin 5/6, and HER2 amplification identified four breast cancer subgroups in a cohort of 270 cases. Cluster subgroup membership was compared with observed and Adjuvant! Online predicted 10-year survival. Survival characteristics were confirmed in an independent cohort of 300 cases assigned to cluster subgroups using a decision tree model. RESULTS: Four distinct breast cancer cluster subgroups (A-D) were identified that were analogous to molecular tumor types and showed a significant association with survival in both the original and validation cohorts (P < 0.001). There was a striking difference between survival for patients in cluster subgroups A and B with ER(+) breast cancer (P < 0.001). Outcome for all tumor types was well estimated by Adjuvant! Online, with the exception of cluster B ER(+) cancers where Adjuvant! Online was too optimistic. CONCLUSIONS: Breast cancer subclassification based on readily accessible pathologic features could improve prognostic assessment of ER(+) breast cancer.

Histopathological features of 'BRCAX' familial breast cancers in the kConFab resource.

AIMS: In recent years histopathology has made an important contribution to the study of familial breast cancer, largely on the basis of the distinctive cancer phenotype commonly identified in BRCA1-mutation carriers. The aim of this study was to identify this phenotype amongst index cases from families in the kConFab familial breast cancer resource with no known pathogenic mutation ('BRCAX' families). METHODS: The histopathology of breast cancer from 180 individuals was reviewed: 132 members of individual BRCAX families, 26 BRCA1 and 15 BRCA2 mutation carriers and seven mutation negative individuals from families with a known pathogenic mutation. RESULTS: BRCAX breast cancers were a heterogeneous group with 25.8% grade 1, 37.9% grade 2 and 36.4% grade 3. Overall, 45/180 (25%) cases were designated 'BRCA1-phenotype' including 22/132 (16.7%) BRCAX cases, 18/26 (69.2%) BRCA1 and 5/15 (33.3%) BRCA2 mutation carriers. For BRCAX cases, a BRCA1 phenotype designation was negatively correlated with age. CONCLUSIONS: Characteristic breast cancer pathology is not diagnostic of a germline BRCA1 mutation, but it does indicate a pathogenic mechanism that occurs with increased frequency in BRCA1 mutation carriers. In BRCAX families, BRCA1 tumour phenotype may signal the presence of an unidentified BRCA1 mutation. However, this finding must be interpreted with regard to limits of the association between histopathology and genotype, and the importance of clinical context.