Sporadic deficient mismatch repair in colorectal cancer increases the risk for non-colorectal malignancy: A European multicenter cohort study.

BACKGROUND AND OBJECTIVES: Disparities between tumors arising via different sporadic carcinogenetic pathways have not been studied systematically. This retrospective multicenter cohort study evaluated the differences in the risk for non-colorectal malignancy between sporadic colorectal cancer (CRC) patients from different DNA mismatch repair status. METHODS: A retrospective European multicenter cohort study including in total of 1706 CRC patients treated between 1996 and 2019 in three different countries. The proficiency (pMMR) or deficiency (dMMR) of mismatch repair was determined by immunohistochemistry. Cases were analyzed for tumor BRAFV600E mutation, and BRAF mutated tumors were further analyzed for hypermethylation status in the promoter region of MLH1 to distinguish between sporadic and hereditary cases. Swedish and Finish patients were matched with their respective National Cancer Registries. For the Czech cohort, thorough scrutiny of medical files was performed to identify any non-colorectal malignancy within 20 years before or after the diagnosis of CRC. Poisson regression analysis was performed to identify the incidence rates of non-colorectal malignancies. For validation purposes, standardized incidence ratios were calculated for the Swedish cases adjusted for age, year, and sex. RESULTS: Of the 1706 CRC patients included in the analysis, 819 were female [48%], median age at surgery was 67 years [interquartile range: 60-75], and sporadic dMMR was found in 188 patients (11%). Patients with sporadic dMMR CRC had a higher incidence rate ratio (IRR) for non-colorectal malignancy before and after diagnosis compared to patients with a pMMR tumor, in both uni- (IRR = 2.49, 95% confidence interval [CI] = 1.89-3.31, p = 0.003) and multivariable analysis (IRR = 2.24, 95% CI = 1.67-3.01, p = 0.004). This association applied whether or not the non-colorectal tumor developed before or after the diagnosis of CRC in both uni- (IRR = 1.91, 95% CI = 1.28-2.98, p = 0.004), (IRR = 2.45, 95% CI = 1.72-3.49, p = 0.004) and multivariable analysis (IRR = 1.67,95% CI = 1.05-2.65, p = 0.029), (IRR = 2.35, 95% CI = 1.63-3.42, p = 0.005), respectively. CONCLUSION: In this retrospective European multicenter cohort study, patients with sporadic dMMR CRC had a higher risk for non-colorectal malignancy than those with pMMR CRC. These findings indicate the need for further studies to establish the need for and design of surveillance strategies for patients with dMMR CRC.

Neuroendocrine Marker Expression in Primary Non-neuroendocrine Epithelial Tumors of the Ovary: A Study of 551 Cases.

Expression of neuroendocrine (NE) markers in primary ovarian non-NE epithelial tumors has rarely been evaluated. The aim of our study was to evaluate the expression of the most widely used NE markers in these neoplasms and to determine any prognostic significance of NE marker expression. The cohort consisted of 551 primary ovarian tumors, including serous borderline tumors, low-grade serous carcinomas, high-grade serous carcinomas (HGSC), clear cell carcinomas, endometroid carcinomas, mucinous borderline tumors, and mucinous carcinomas. Immunohistochemical analysis was performed using antibodies against INSM1, synaptophysin, chromogranin, and CD56 on tissue microarray. Positivity for INSM1, synaptophysin, chromogranin, and CD56 was most frequently observed in mucinous tumors (48.7%, 26.0%, 41.5%, and 100%, respectively). The positivity for these NE markers was mostly restricted to nonmucinous elements distributed throughout the tumor. The mucinous borderline tumor and mucinous carcinomas groups had similar proportions of positivity (mucinous borderline tumor: 53%, mucinous carcinomas: 39%). In the other tumor types, except for HGSC, there was only focal expression (5%-10%) or negativity for NE markers. HGSC showed high CD56 expression (in 26% of cases). Survival analysis was only performed for CD56 in HGSC as this was the only group with sufficient positive cases, and it showed no prognostic significance. Except for mucinous tumors, expression of NE markers in non-NE ovarian epithelial tumors is low. CD56 expression in HGSC occurs frequently but is without diagnostic or prognostic value.

Primary Mucinous Tumors of the Ovary: An Interobserver Reproducibility and Detailed Molecular Study Reveals Significant Overlap Between Diagnostic Categories.

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms, and their diagnosis may be challenging. We analyzed 124 primary ovarian mucinous tumors originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and the potential for diagnostic support by molecular profiling using a next-generation sequencing targeted panel of 727 DNA and 147 RNA genes. Fourteen experienced pathologists independently assigned a diagnosis from preset options, based on a review of a single digitized slide from each tumor. After excluding 1 outlier participant, there was a moderate agreement in diagnosing the 124 cases when divided into 3 categories (κ = 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT as a combined category and MC was found in only 36.3% of the cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic. After a reclassification of the tumors into near-consensus diagnostic categories on the basis of the initial participant results, a comparison of molecular findings between the MBT and MC groups did not show major and unequivocal differences between MBTs and MCs or between MCs with expansile vs infiltrative pattern of invasion. In contrast, HER2 overexpression or amplification was found only in 5.3% of MBTs and in 35.3% of all MCs and in 45% of MCs with expansile invasion. Overall, HER2 alterations, including mutations, were found in 42.2% of MCs. KRAS mutations were found in 65.5% and PIK3CA mutations in 6% of MCs. In summary, although the diagnostic criteria are well-described, diagnostic agreement among our large group of experienced gynecologic pathologists was only moderate. Diagnostic categories showed a molecular overlap. Nonetheless, molecular profiling may prove to be therapeutically beneficial in advanced-stage, recurrent, or metastatic MCs.

Recurrent novel HMGA2-NCOR2 fusions characterize a subset of keratin-positive giant cell-rich soft tissue tumors.

Giant cell tumors of soft tissue (GCT-ST) are rare low-grade neoplasms that were at one time thought to represent the soft tissue counterparts of GCT of bone (GCT-B) but are now known to lack the H3F3 mutations characteristic of osseous GCT. We present six distinctive giant cell-rich soft tissue neoplasms that expressed keratins and carried a recurrent HMGA2-NCOR2 gene fusion. Patients were five females and one male aged 14-60 years (median, 29). All presented with superficial (subcutaneous) masses that were removed by conservative marginal (3) or wide (2) local excision. The tumors originated in the upper extremity (2), lower extremity (2), head/neck (1), and trunk (1). Five patients with follow-up (median, 21 months; range, 14-168) remained disease-free. Grossly, all tumors were well-demarcated but not encapsulated with variable lobulation. Histologically, they were composed of bland plump epithelioid or ovoid to spindled mononuclear cells admixed with evenly distributed multinucleated osteoclast-type giant cells. Foci of stromal hemorrhage and hemosiderin were seen in all cases. The mitotic activity ranged from 2 to 14/10 high power fields (median: 10). Foci of necrosis and vascular invasion were seen in one case each. The mononuclear cells were immunoreactive with the AE1/AE3 keratin cocktail and less frequently/less diffusely for K7 and K19 but lacked expression of other lineage-associated markers. RNA-based next-generation sequencing revealed an HMGA2-NCOR2 fusion in all tumors. None of the keratin-negative conventional GCT-ST showed the HMGA2-NCOR2 fusion (0/7). Metaplastic bone (4/9) and SATB2 expression (3/4) were frequent in keratin-negative conventional GCT-ST but were lacking in keratin-positive HMGA2-NCOR2 fusion-positive tumors. The distinctive immunophenotype and genotype of these tumors strongly suggest that they represent a discrete entity, differing from conventional GCT-ST and other osteoclast-rich morphologic mimics. Their natural history appears favorable, although a study of additional cases and longer follow-up are warranted.

Molecular testing in endometrial carcinoma - joint recommendation of Czech Oncological Society, Oncogynecological Section of the Czech Gynecological and Obstetrical Society, Society of Radiation Oncology, Biology and Physics, and the Society of Czech Pathologists.

Molecular classification of endometrial carcinoma is becoming an important part of the dia-gnostic process with direct therapeutic implications. Recent international guidelines, including the joint recommendation of the European Society of Gynaecological Oncology, the European Society for Radiotherapy and Oncology and the European Society of Pathology include the molecular classification into standard dia-gnostic algorithms. Molecular testing of endometrial carcinomas is also recommended in the latest (5th edition) of the World Health Organization classification of female genital tumors. Due to the need to implement these recommendations in practice, representatives of four professional societies of the Czech Medical Association of J. E. Purkyně (the Czech Oncological Society, the Oncogynecological Section of the Czech Gynecological and Obstetrical Society, the Society of Radiation Oncology, Biology and Physics, and the Society of Czech Pathologists) organized a meeting focused on this topic. Recommendation for molecular testing of endometrial carcinoma in routine dia-gnostic practice in the Czech Republic.

Review of tumor infiltrating lymphocytes assessment in breast cancer in routine diagnostic practice.

Evaluation of tumor infiltrating lymphocytes (TIL) is gaining importance in many cancers not only because of their prognostic, but also predictive significance. One of the tumors in which the evaluation of TIL is of prognostic importance and has potential predictive impact on the modification of treatment procedures is breast cancer, especially its so-called triple negative, and HER2 positive variants.The aim of this review is to provide an overview of the issue of TIL evaluation in breast cancer, focusing not only on the clinical significance of this evaluation, but especially on the methodological aspects of evaluation and standardized reporting of the results.

Molecular testing in endometrial carcinoma (Joint recommendation of Czech Oncological Society, Oncogynecological Section of the Czech Gynecological and Obstetrical Society, Society of Radiation Oncology, Biology and Physics, and the Society of Czech Pathologists).

Molecular classification of endometrial carcinoma is becoming an important part of the diagnostic process with direct therapeutic implications. Recent international guidelines, including the joint ESGO-ESTRO-ESP recommendation, include the molecular classification into standard diagnostic algorithms. Molecular testing of endometrial carcinomas is also recommended in the latest (5th) edition of the WHO classification of Female Genital Tumors. Due to the need to implement these recommendations in practice, representatives of four professional societies of Czech Medical Association of J. E. Purkyně (Czech Oncological Society, Oncogynecological Section of the Czech Gynecological and Obstetrical Society, Society of Radiation Oncology, Biology and Physics, and the Society of Czech Pathologists) organized a meeting focused on this topic. The result of this meeting is a joint recommendation for molecular testing of endometrial carcinoma in routine diagnostic practice in the Czech Republic.

Plasticity and intratumoural heterogeneity of cell surface antigen expression in breast cancer.

Background:The intratumoural heterogeneity, often driven by epithelial-to-mesenchymal transition (EMT), significantly contributes to chemoresistance and disease progression in adenocarcinomas. Methods:We introduced a high-throughput screening platform to identify surface antigens that associate with epithelial­mesenchymal plasticity in well-defined pairs of epithelial cell lines and their mesenchymal counterparts. Using multicolour flow cytometry, we then analysed the expression of 10 most robustly changed antigens and identified a 10-molecule surface signature, in pan-cytokeratin-positive/EpCAM-positive and -negative fractions of dissociated breast tumours. Results:We found that surface CD9, CD29, CD49c, and integrin ß5 are lost in breast cancer cells that underwent EMT in vivo. The tetraspanin family member CD9 was concordantly downregulated both in vitro and in vivo and associated with epithelial phenotype and favourable prognosis. Conclusions:We propose that overall landscape of 10-molecule surface signature expression reflects the epithelial­mesenchymal plasticity in breast cancer.

[Prediction of EGFR blockade responses in metastatic colorectal carcinoma]. / Predikce odpovedi metastatického kolorektálního karcinomu na cílenou anti-EGFR lécbu.

The combination of modern systemic chemotherapy and anti-EGFR monoclonal antibodies improves overall survival and the quality of life for patients with metastatic colorectal cancer. By contrast, the addition of anti-EGFR therapy to the treatment regime of resistant patients may lead to worse progression-free and overall survival. Therofore, identifying sensitive and resistant patients is key during initial decision-making. A number of clinical trials show that primary resistance to EGFR blockade is in most cases caused by constitutive activation of signalling pathways downstream of EGFR. Of the many biomarkers studied, only the KRAS and NRAS mutation status has reached clinical relevance in routine practice. The other markers (BRAF and PIK3CA mutations, PTEN and TP53 inactivation, EGFR and HER-2 amplification, epiregulin and amphiregulin overexpression, microRNA miR-31-3p and miR-31-5p etc.) still need to be validated. The accuracy of predictive diagnostic tools could also be increased by a combination of predictive markers on the next generation sequencing platform.

[Remission of the disease associated/related with immunoglobulin IgG4 accompanied by multiple lymphadenopathy after treatment with rituximab and dexamethasone: a case report]. / Remise "the disease associated/related with immunoglobulin IgG4" provázeného mnohocetnou lymfadenopatií po lécbe rituximabem a dexametazonem: kazuistika.

A disease associated with immunoglobulin IgG4 is a rare unit with very variable symptoms. We describe the course and treatment of the disease in a patient who presented with multiple lymphadenopathy and infiltrates in the area of the retroperitoneum and pelvis and signs of chronic sclerosing pancreatitis. The disease was clinically manifested by a significant loss of weight, but also by a loss of perception of taste and smell. The diagnosis was made based on a high amount of IgG4 expressing plasma cells in the sampled tissue and an increased concentration of immunoglobulins of type IgG and mainly subclass IG4. Rituximab in 475 mg/m2 dose was used in the treatment, the initial four doses of rituximab were administered at 14-day intervals, always with a one-off administration of a 40 mg dose of dexamethasone. According to FDG-PET/CT, only partial remission of the disease was reached after 4 applications of rituximab and dexamethasone. The patient recovered its sense of smell and taste. In another 4 cycles ritu-ximab was administered on day 1 of a 28-day cycle. On days 1 and 15 of the cycle dexamethasone at 40 mg and cyclophosphamide at 600 mg were administered by intravenous infusion. After the completion of 8 cycles of treatment based on rituximab and dexamethasone and with cyclophosphamide added in the second half of the treatment, the control FDG-PET/CT examination proved the complete remission. Before the treatment commencement the concentration of the subclass of immunoglobulin IgG4 was equal to 51.0 g/l, after the completion of the aforementioned treatment it dropped to 3.5 g/l. The patient tolerated the treatment without any adverse effects. Ritu-ximab, dexamethasone and cyclophosphamide induced the complete remission of this disease.Key words: IgG4-associated/releated disease - rituximab.

Panitumumab use in metastatic colorectal cancer and patterns of RAS testing: results from a Europe-wide physician survey and medical records review.

BACKGROUND: In Europe, treatment of metastatic colorectal cancer (mCRC) with panitumumab requires prior confirmation of RAS wild-type mutation status. Two studies - a physician survey and a medical records review (MRR) - were conducted to evaluate the use of panitumumab and awareness among prescribing oncologists of the associated RAS testing requirements in clinical practice. METHODS: Both studies enrolled participants from nine European countries and were carried out in three consecutive rounds. Rounds 1 and 2 (2012-2013) examined KRAS (exon 2) testing only; the results have been published in full previously. Round 3 (2014-2015) examined full RAS testing (exons 2, 3, 4 of KRAS and NRAS) and was initiated following a change in prescribing guidelines, from requiring KRAS alone to requiring full RAS testing. For the physician survey, telephone interviews were conducted with oncologists who had prescribed panitumumab to patients with mCRC in the previous 6 months. For the MRR, oncologists were asked to provide anonymised clinical information, extracted from their patients' records. RESULTS: In Round 3, 152 oncologists and 131 patients' records were included in the physician survey and MRR, respectively. In Round 3 of the physician survey, 95.4% (n = 145) of participants correctly identified that panitumumab should only be prescribed in RAS wild-type mCRC compared with 99.0% (n = 298) of 301 participants in Rounds 1 and 2, responding to the same question about KRAS testing. In Round 3 of the MRR, 100% (n = 131) of patients included in the study had confirmed KRAS or RAS wild-type status prior to initiation of panitumumab compared with 97.7% (n = 299) of 306 patients in Rounds 1 and 2 (KRAS only). Of those patients in Round 3, 83.2% (n = 109) had been tested for RAS status and 16.8% (n = 22) had been tested for KRAS status only. CONCLUSIONS: Physicians' adherence to prescribing guidelines has remained high over time in Europe, despite the change in indication for panitumumab treatment, from KRAS to RAS wild-type mCRC. Additionally, this study demonstrates the uptake of full RAS testing among the majority of oncologists and pathologists.

Serum-based microRNA signatures in early diagnosis and prognosis prediction of colon cancer.

Early detection of colorectal cancer is the main prerequisite for successful treatment and reduction of mortality. Circulating microRNAs were previously identified as promising diagnostic, prognostic and predictive biomarkers. The purpose of this study was to identify serum microRNAs enabling early diagnosis and prognosis prediction of colon cancer. In total, serum samples from 427 colon cancer patients and 276 healthy donors were included in three-phase biomarker study. Large-scale microRNA expression profiling was performed using Illumina small RNA sequencing. Diagnostic and prognostic potential of identified microRNAs was validated on independent training and validation sets of samples using RT-qPCR. Fifty-four microRNAs were found to be significantly deregulated in serum of colon cancer patients compared to healthy donors (P < 0.01). A diagnostic four-microRNA signature consisting of miR-23a-3p, miR-27a-3p, miR-142-5p and miR-376c-3p was established (AUC = 0.917), distinguishing colon cancer patients from healthy donors with sensitivity of 89% and specificity of 81% (AUC = 0.922). This panel of microRNAs exhibited high diagnostic performance also when analyzed separately in colon cancer patients in early stages of the disease (T1-4N0M0; AUC = 0.877). Further, a prognostic panel based on the expression of miR-23a-3p and miR-376c-3p independent of TNM stage was established (HR 2.30; 95% CI 1.44-3.66; P < 0.0004). In summary, highly sensitive signatures of circulating microRNAs enabling non-invasive early detection and prognosis prediction of colon cancer were identified.

[Breast cancer in BRCA1/2 mutation carriers]. / Karcinomy prsu u nosicek mutací BRCA 1/2.

Inherited mutations in BRCA1 and BRCA2 genes represent the most important cause of hereditary breast cancer. This highly penetrating familial cancer syndrome, including also the onset of ovarian cancer and other malignancies at relatively low age, represents a substantial medical problem. The affected families should be managed actively. When compared to spontaneous tumors, the breast carcinomas in BRCA1 mutation carriers exhibit a relatively different, despite non-specific, phenotype (often triple negative, medullary features) arousing suspicion of hereditary background. In the contrary, the distribution of phenotypes of breast carcinomas in BRCA2 carriers is similar to distribution in the non-affected population. The lymphocytic lobulitis is observed significantly more often in non-cancerous breast tissue of BRCA1/2 mutation carriers, but again, this feature is not specific.

Differential expression of anterior gradient protein 3 in intrahepatic cholangiocarcinoma and hepatocellular carcinoma.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer next to hepatocellular carcinoma (HCC). Despite the significant difference of the therapeutic strategy for both diseases, their histological appearance may be very similar. Thus the correct diagnosis is crucial for treatment choice but is often difficult to achieve. The aim of our study was to evaluate anterior gradient 3 (AGR3) as a new diagnostic marker helping to distinguish between ICC and HCC. AGR3 is a putative transmembrane protein implicated in breast, prostate and ovary tumorigenesis and belongs to the family of protein disulfide isomerases. Since there is little information on how AGR3 is expressed in normal and diseased tissues and what its exact function is, we analyzed its expression pattern in normal liver and tumor tissue of ICC and HCC. The immunohistochemical analysis in normal tissue revealed specific AGR3 expression in intrahepatic bile duct cholangiocytes which was not present in liver hepatocytes. Consequently we analyzed AGR3 expression in 74 representative samples of puncture biopsies, tissue excisions and resection specimens from which 48 samples were diagnosed as HCC and 26 as ICC. Our results showed AGR3 expression negative and weakly positive respectively in hepatocellular carcinomas compared to stronger AGR3 positivity in cholangiocellular carcinomas. AGR3 expression statistically significantly correlated to acid mucopolysaccharide expression and negatively correlated to glypican-3 expression. We conclude that according to receiver operating characteristics (ROC) analysis AGR3 expression is relatively specific for ICC and is potentially linked to mucosecretion, which may indicate potential implication in treatment resistance.

Somatic Genomic and Transcriptomic Characterization of Primary Ovarian Serous Borderline Tumors and Low-Grade Serous Carcinomas.

Low-grade serous carcinoma (LGSC) may develop from serous borderline tumor (SBT) tissue, where the micropapillary type (mSBT) presents the highest risk for progression. The sensitivity of LGSC to standard chemotherapy is limited, so alternative therapeutic approaches, including targeted treatment, are needed. However, knowledge about the molecular landscape of LGSC and mSBT is limited. A sample set of 137 pathologically well-defined cases (LGSC, 97; mSBT, 40) was analyzed using capture DNA next-generation sequencing (727 genes) and RNA next-generation sequencing (147 genes) to show the landscape of somatic mutations, gene fusions, expression pattern, and prognostic and predictive relevance. Class 4/5 mutations in the main driver genes (KRAS, BRAF, NRAS, ERBB2, USP9X) were detected in 48% (14/29) of mSBT cases and 63% (47/75) of LGSC cases. The USP9X mutation was detected in only 17% of LGSC cases. RNA next-generation sequencing revealed gene fusions in 6 of 64 LGSC cases (9%) and 2 of 33 mSBT cases (9%), and a heterogeneous expression profile across LGSC and mSBT. No molecular characteristics were associated with greater survival. The somatic genomic and transcriptomic profiles of 35 mSBT and 85 LGSC cases are compared for the first time. Candidate oncogenic gene fusions involving BRAF, FGFR2, or NF1 as a fusion partner were identified. Molecular testing of LGSC may be used in clinical practice to reveal therapeutically significant targets.

Primary Breast Sarcoma: A Two-Centre Analysis and Review of Literature.

Introduction: Primary breast sarcoma is a very rare malignant type of breast tumours with an incidence of 0.1% of all primary breast malignancies. Methods: We present a retrospective analysis of the case series from two hospitals in the Czech Republic with a review of the diagnostic and treatment approach to primary breast sarcomas with an analysis of published prognostic factors. Results: Eleven patients were included in the study, 9 women and 2 men. Statistical evaluation revealed that tumour size (p = 0.1964), grade (p = 0.1667), margin distance (p = 0.5403), mitotic activity (p = 0.8577), or age (p = 0.7822) were not prognostic factors in our cohort. Conclusion: The analysis did not prove any of the factors, such as age, tumour size, grade, or mitotic activity, to be statistically significant prognostic factors. Based on the literature review, the most common published prognostic factors are tumour size, margin status, and grade, but the results are ambiguous.

FoxP3 Expression in Tumor-Infiltrating Lymphocytes as Potential Predictor of Response to Immune Checkpoint Inhibitors in Patients with Advanced Melanoma and Non-Small Cell Lung Cancer.

Immune checkpoint inhibitors (ICI) are the main therapy currently used in advanced malignant melanoma (MM) and non-small cell lung cancer (NSCLC). Despite the wide variety of uses, the possibility of predicting ICI efficacy in these tumor types is scarce. The aim of our study was to find new predictive biomarkers for ICI treatment. We analyzed, by immunohistochemistry, various cell subsets, including CD3+, CD8+, CD68+, CD20+, and FoxP3+ cells, and molecules such as LAG-3, IDO1, and TGFß. Comprehensive genomic profiles were analyzed. We evaluated 46 patients with advanced MM (31) and NSCLC (15) treated with ICI monotherapy. When analyzing the malignant melanoma group, shorter median progression-free survival (PFS) was found in tumors positive for nuclear FoxP3 in tumor-infiltrating lymphocytes (TILs) (p = 0.048, HR 3.04) and for CD68 expression (p = 0.034, HR 3.2). Longer PFS was achieved in patients with tumors with PD-L1 TPS ≥ 1 (p = 0.005, HR 0.26). In the NSCLC group, only FoxP3 positivity was associated with shorter PFS and OS. We found that FoxP3 negativity was linked with a better response to ICI in both histological groups.

Single-cell protein profiling defines cell populations associated with triple-negative breast cancer aggressiveness.

Triple-negative breast cancer (TNBC) is an aggressive and complex subtype of breast cancer that lacks targeted therapy. TNBC manifests characteristic, extensive intratumoral heterogeneity that promotes disease progression and influences drug response. Single-cell techniques in combination with next-generation computation provide an unprecedented opportunity to identify molecular events with therapeutic potential. Here, we describe the generation of a comprehensive mass cytometry panel for multiparametric detection of 23 phenotypic markers and 13 signaling molecules. This single-cell proteomic approach allowed us to explore the landscape of TNBC heterogeneity, with particular emphasis on the tumor microenvironment. We prospectively profiled freshly resected tumors from 26 TNBC patients. These tumors contained phenotypically distinct subpopulations of cancer and stromal cells that were associated with the patient's clinical status at the time of surgery. We further classified the epithelial-mesenchymal plasticity of tumor cells, and molecularly defined phenotypically diverse populations of tumor-associated stroma. Furthermore, in a retrospective tissue-microarray TNBC cohort, we showed that the level of CD97 at the time of surgery has prognostic potential.

Immunohistochemical expression of PRAME in 485 cases of epithelial tubo-ovarian tumors.

Preferentially expressed antigen of melanoma (PRAME) is a cancer/testis antigen selectively expressed in somatic tissues and various solid malignant tumors and is associated with poor prognostic outcome. Our research aimed to comprehensively compare its expression in a large cohort of tubo-ovarian epithelial tumors and examine its correlation with our clinico-pathologic data, as well as to assess its potential use in diagnostics and therapy.We examined 485 cases of epithelial tubo-ovarian tumors including 107 clear cell carcinomas (CCC), 52 endometroid carcinomas (EC), 103 high grade serous carcinomas (HGSC), 119 low grade serous carcinomas (LGSC)/micropapillary variant of serous borderline tumors (mSBT), and 104 cases of mucinous carcinomas (MC)/mucinous borderline tumors (MBT). The immunohistochemical analysis was performed using TMAs.The highest levels of expression were seen in EC (60%), HGSC (62%), and CCC (56%), while expression in LGSC/mSBT (4%) and MC/MBT (2%) was rare. The clinico-pathologic correlations and survival analysis showed no prognostic significance.The results of our study showed that PRAME is neither prognostic nor a suitable ancillary marker in the differential diagnosis of tubo-ovarian epithelial tumors. Nevertheless, knowledge about the PRAME expression may be important concerning its potential predictive significance, because targeting PRAME as a potential therapeutic option is currently under investigation.

HER2 status as a potential predictive biomarker for ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a subtype of ovarian carcinoma characterized by unique biological features and highly malignant characteristics including low chemosensitivity. Therefore, new therapeutic targets are needed. These could include the downstream pathways of receptor tyrosine kinases, especially the human epidermal growth factor receptor 2 (HER2). Our main objective was to characterize the HER2 status using immunohistochemistry (IHC) and FISH on 118 OCCCs, also considering the novel paradigm of HER2-zero and HER2-low status. Other aims included determination of the association between HER2 status and survival, HER2 gene DNA and RNA NGS analysis, HER2 gene expression analysis, and correlation between IHC and gene expression in HER2-zero and HER2-low cases. Cases with HER2 overexpression/amplification accounted for 5.1% (6/118), with additional 3% harbouring HER2 gene mutation. The remaining 112 (94.9%) cases were HER2-negative. Of these, 75% were classified as HER2-zero and 25% as HER2-low. This percentage of HER2 aberrations is significant concerning their possible therapeutic influence. Cases from the HER2-zero group showed significantly better survival. Although this relationship lost statistical significance in multivariate analysis, the results have potential therapeutic significance. HER2 gene expression analysis showed a significant correlation with HER2 IHC status in the entire cohort (HER2-positive vs. HER2-negative), while in the cohort of only HER2-negative cases, the results did not reach statistical significance, suggesting that gene expression analysis would not be suitable to confirm the subdivision into HER2-low and HER2-zero. Our results also emphasize the need for standardized HER2 testing in OCCC to determine the best predictor of clinical response.