Concordance between ER, PR, Ki67, and HER2‐low expression in breast cancer by MammaTyper RT‐qPCR and immunohistochemistry:implications for the practising pathologist

Background: There are limited data on the role of multigene tests and their correlation with immunohistochemistry (IHC), especially on core biopsy. MammaTyper is a quantitative conformite Europeeanne (CE) marked, National Institute for Health and Care excellence (NICE) approved, in in vitro diagnostic quantitative real‐time polymerase chain reaction (RT‐qPCR) test for assessment of mRNA expression of four biomarkers (ESR1, PGR, ERBB2, MKI67).Methods: We evaluated the concordance of MammaTyper with oestrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 by IHC on 133 core needle biopsies of breast cancer. HER2 was positive if IHC 3+ or 2+ and fluorescence in situ hybridization (FISH)‐amplified. Global and hotspot Ki67 expression was analysed using a cutoff of ≥20% assessed manually and by digital image analysis. Agreements were expressed as overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen's kappa. Results: RT‐qPCR results of ESR1 were highly concordant with IHC with OPA of 94.7% using 1% cutoff and 91.7% when the low ER‐positive category was included. The PPA and NPA between RT‐qPCR and IHC for PR was 91.5% and 88.0%, respectively, when using the 1% cutoff. For ERBB2/HER2, the OPA was 95% and the PPA was 84.6%. 40 of 72 HER2 IHC score 0 tumours were classified as ERBB2 low. Best concordance between MKI67 by MammaTyper and Ki67 IHC was achieved using hotspot digital image analysis (OPA: 87.2%, PPA: 90.6%, NPA: 80%).Conclusion: RT‐qPCR‐based assessment of the mRNA expression of ESR1, PGR, ERBB2, and MKI67 showed high concordance with IHC, suggesting that the MammaTyper test on core needle biopsies represents a reliable, efficient, and reproducible alternative for breast cancer classification and refining HER2 low categorisation

Tall Cell Carcinoma with Reversed Polarity:Case Report of a Rare Special Type of Breast Cancer and Review of the Literature

Background: Tall cell carcinoma of the breast with reversed polarity (TCCRP) is a rare type of invasive breast cancer with overlapping features with papillary thyroid carcinoma and a characteristic molecular profile. Few cases have been reported in the literature since the first case was described in 2003. Case presentation: We present the case of a 41-year-old female with a symptomatic left breast lump. Image-guided core biopsy was diagnosed as triple-negative apocrine carcinoma. Surgical excision revealed an invasive carcinoma with solid papillary pattern, nuclei arranged away from the basement membrane (reversed polarity) and luminal eosinophilic colloid-like material. The tumour was GATA3-, CK5-, CK14- and CK7-positive and TTF1-negative. Specialist opinion and the identification of hotspot mutations in the IDH2 p.Arg172 gene via PCR confirmed the diagnosis of TCCRP. Conclusions: TCCRP is a relatively recently recognised papillary epithelial neoplasm with characteristic morphological features and molecular profile. Due to its rarity, TCCRP can be diagnostically challenging, and features can be mistaken for benign and malignant lesions. Accurate diagnosis is important in effective treatment of this indolent malignant triple-negative breast cancer, which carries an excellent prognosis

Heterogeneity of germline variants in high risk breast and ovarian cancer susceptibility genes in India

Breast and ovarian cancers now account for one in three cancers in Indian women and their incidence is rising. Major differences in the clinical presentation of breast and ovarian cancers exist between India and the United Kingdom. For example, Indian patients with breast cancer typically present a decade earlier than in the UK. Reasons for this could be multifactorial, including differences in underlying biology, environmental risks, and other systematic factors including access to screening. One possible explanation lies in variable incidence or penetrance of germline mutations in genes such as BRCA1 and BRCA2. We performed a methodical database and literature review to investigate the prevalence and spectrum of high-risk cancer susceptibility genes in Indian patients with breast and ovarian cancers. We identified 148 articles, but most studies were small, with inconsistent inclusion criteria and based on heterogeneous technologies, so that mutation frequency could not be reliably ascertained. Data were also often lacking on penetrance, histopathology, and survival outcomes. After filtering out unsuitable studies, only 13 remained, comprising 1028 patients. Large-scale research studies are urgently needed to determine mutation prevalence, spectra, and clinico-pathological features, and hence derive guidelines for screening, treatment, and prevention specific to the Indian population

Loss of CSMD1 expression is associated with high tumour grade and poor survival in invasive ductal breast carcinoma

International audienceCUB and SUSHI multiple domain protein 1 () is a candidate tumour suppressor gene that maps to chromosome 8p23, a region deleted in many tumour types including 50% of breast cancers. CSMD1 has homologies to proteins implicated in carcinogenesis. We aimed to study the expression pattern of the CSMD1 protein and evaluate its prognostic importance in invasive ductal carcinoma (IDC). An anti-CSMD1 antibody was developed and validated. The expression pattern of CSMD1 in normal breast and IDC samples was investigated by immunohistochemistry in 275 patients. Univariate and multivariate Cox regression analyses were performed. In normal breast duct epithelial cells, luminal, membranous and cytoplasmic CSMD1 staining was identified. Reduced expression of CSMD1 was detected in 79/275 (28.7%) of IDC cases. Low CSMD1 expression was significantly associated with high tumour grade ( = 0.003). CSMD1 expression was associated with overall survival (OS; HR = 0.607, 95%CI: 0.4-0.91,  = 0.018) but not with disease-free survival (DFS; HR = 0.81, 95%CI: 0.46-1.43,  = 0.48). Multivariate analysis showed that CSMD1, together with Nottingham Prognostic Index, was considered an independent predictor of OS (HR = 0.607, 95%CI: 0.4-0.91,  = 0.018) but not DFS (HR = 0.84, 95%CI: 0.46-1.5,  = 0.573). Reduction of CSMD1 expression was significantly associated with high tumour grade and decreased OS. Therefore, our results support the idea that is a tumour suppressor gene and suggest its possible use as a new prognostic biomarker. The membrane expression pattern of CSMD1 suggests that it may be a receptor or co-receptor involved in the process of signal transduction

Profiling of Tumour-Infiltrating Lymphocytes and Tumour-Associated Macrophages in Ovarian Epithelial Cancer:Relation to Tumour Characteristics and Impact on Prognosis

Early evidence suggests a strong impact of tumour-infiltrating lymphocytes (TILs) on both the prognosis and clinical behaviour of ovarian cancer. Proven associations, however, have not yet translated to successful immunotherapies and further work in the field is urgently needed. We aimed to analyse the tumour microenvironment of a well-characterised cohort of ovarian cancer samples. Tumour markers were selected owing to their comparative underrepresentation in the current literature. Paraffin-embedded, formalin-fixed tumour tissue blocks of 138 patients representative of the population and including early stage disease were identified, stained for CD3, CD20, CD68 and CD163 and analysed for both the stromal and intertumoral components. Data were statistically analysed in relation to clinical details, histological subtype, borderline vs. malignant status, survival and management received. Mean stromal CD3, total CD3 count, mean stromal CD20 and total CD20 count all correlated negatively with survival. Malignant ovarian tumours consistently demonstrated significantly higher infiltration of all analysed immune cells than borderline tumours. Assessment of the stromal compartment produced a considerably higher proportion of significant results when compared to the intra-tumoural infiltrates. Customary assessment of solely intra-tumoural cells in advanced stage disease patients undergoing primary debulking surgery should be challenged, with recommendations for future scoring systems provided

Proline-Rich Homeodomain protein (PRH/HHEX) is a suppressor of breast tumour growth

Breast tumours progress from hyperplasia to ductal carcinoma in situ (DCIS) and invasive breast carcinoma (IBC). PRH/HHEX (Proline Rich Homeodomain/Haematopoietically expressed homeobox) is a transcription factor that displays both tumour suppressor and oncogenic activity in different disease contexts however, the role of PRH in breast cancer is poorly understood. Here we show that nuclear localisation of the PRH protein is decreased in DCIS and IBC compared to normal breast. Our previous work has shown that PRH phosphorylation by protein kinase CK2 prevents PRH from binding to DNA and regulating the transcription of multiple genes encoding growth factors and growth factor receptors. Here we show that transcriptionally inactive phosphorylated PRH is elevated in DCIS and IBC compared to normal breast. To determine the consequences of PRH loss of function in breast cancer cells we generated inducible PRH depletion in MCF-7 cells. We show that PRH depletion results in increased MCF-7 cell proliferation in part at least due to increased vascular endothelial growth factor signaling. Moreover we demonstrate that PRH depletion increases the formation of breast cancer cells with cancer stem cell-like properties. Finally, and in keeping with these findings, we show that PRH over-expression inhibits the growth of mammary tumours in mice. Collectively these data indicate that PRH plays a tumour suppressive role in the breast and they provide an explanation for the finding that low PRH mRNA levels are associated with a poor prognosis in breast cancer

Inter- and Intra-Observer Agreement of PD-L1 SP142 Scoring in Breast Carcinoma:A Large Multi-Institutional International Study

The assessment of PD-L1 expression in TNBC is a prerequisite for selecting patients for immunotherapy. The accurate assessment of PD-L1 is pivotal, but the data suggest poor reproducibility. A total of 100 core biopsies were stained using the VENTANA Roche SP142 assay, scanned and scored by 12 pathologists. Absolute agreement, consensus scoring, Cohen's Kappa and intraclass correlation coefficient (ICC) were assessed. A second scoring round after a washout period to assess intra-observer agreement was carried out. Absolute agreement occurred in 52% and 60% of cases in the first and second round, respectively. Overall agreement was substantial (Kappa 0.654-0.655) and higher for expert pathologists, particularly on scoring TNBC (6.00 vs. 0.568 in the second round). The intra-observer agreement was substantial to almost perfect (Kappa: 0.667-0.956), regardless of PD-L1 scoring experience. The expert scorers were more concordant in evaluating staining percentage compared with the non-experienced scorers (R2 = 0.920 vs. 0.890). Discordance predominantly occurred in low-expressing cases around the 1% value. Some technical reasons contributed to the discordance. The study shows reassuringly strong inter- and intra-observer concordance among pathologists in PD-L1 scoring. A proportion of low-expressors remain challenging to assess, and these would benefit from addressing the technical issues, testing a different sample and/or referring for expert opinions

Neratinib could be effective as monotherapy or in combination with trastuzumab in HER2-low breast cancer cells and organoid models

BACKGROUND: Previous studies have suggested that patients with HER2-low breast cancers do not benefit from trastuzumab treatment although the reasons remain unclear.METHODS: We investigated the effect of trastuzumab monotherapy and its combination with different HER2 targeting treatments in a panel of breast cancer cell lines and patient-derived organoids (PDOs) using biochemical methods and cell viability assays.RESULTS: Compared to sensitive HER2 over-expressing (IHC3 + ) breast cancer cells, increasing doses of trastuzumab could not achieve IC50 in MDA-MB-361 (IHC 2 + FISH + ) and MDA-MB-453 (IHC 2 + FISH-) cells which showed an intermediate response to trastuzumab. Trastuzumab treatment induced upregulation of HER ligand release, resulting in the activation of HER receptors in these cells, which could account for their trastuzumab insensitivity. Adding a dual ADAM10/17 inhibitor to inhibit the shedding of HER ligands in combination with trastuzumab only showed a modest decrease in the cell viability of HER2-low breast cancer cells and PDOs. However, the panHER inhibitor neratinib was an effective monotherapy in HER2-low breast cancer cells and PDOs, and showed additive effects when combined with trastuzumab.CONCLUSION: This study demonstrates that neratinib in combination with trastuzumab may be effective in a subset of HER2-low breast cancers although further validation is required in a larger panel of PDOs and in future clinical studies.</p