Nectin-4 and DNA mismatch repair proteins expression in upper urinary tract urothelial carcinoma (UTUC) as a model for tumor targeting approaches: an ImGO pilot study.

BACKGROUND: Upper urinary tract urothelial carcinoma (UTUC) accounts for only about 5-10% of all urothelial cancers and is characterized by an aggressive and frequently rapidly fatal behavior. However, detailed knowledge of its molecular profile is still lacking. MATERIALS AND METHODS: We identified, by chart analysis, patients who underwent radical nephroureterectomy or diagnostic biopsy for UTUC between January 2015 and August 2020 at the Santa Maria Hospital of Terni, in Italy. Eligible patients were required to have also adequate clinical informations and follow-up details. The primary objective of the study was to evaluate DNA mismatch repair (MMR) proteins and Nectin-4 immunohistochemical expression in UTUC, looking also for an eventual correlation between these molecular features. The secondary objective was to investigate genomic instability in the case of a MMR protein loss. Expression of proteins was assessed by using immunohistochemistry and microsatellite instability (MSI) performed by next generation sequencing. Nectin-4 expression was reported using an intensity scoring system (score, 0-3+), instead the expression of DNA MMR proteins was indicated as present (no loss) or not present (loss). RESULTS: Thirty four cases have been evaluated and 27 considered eligible for the study with their tumor samples analyzed. Nectin-4 was found to be expressed in 44% of cases and 18.5% of patients showed defective-MMR phenotype. We found a significant correlation between Nectin-4 expression and MSH2/MSH6 protein loss. Out of 7 patients with DNA MMR proteins loss or equivocal phenotype, 3 showed MSI. CONCLUSIONS: Our pilot study suggest a possible relationship between Nectin-4 and DNA MMR protein expression in UTUC and a clinically significant correlation between defective MMR phenotype and genomic instability. Because of the possible implications of these data for innovative treatment approaches, the need for further studies in this area is warranted.

Primary effusion lymphoma occurring in the setting of transplanted patients: a systematic review of a rare, life-threatening post-transplantation occurrence.

BACKGROUND: Primary effusion lymphoma is a rare, aggressive large B-cell lymphoma strictly linked to infection by Human Herpes virus 8/Kaposi sarcoma-associated herpes virus. In its classic form, it is characterized by body cavities neoplastic effusions without detectable tumor masses. It often occurs in immunocompromised patients, such as HIV-positive individuals. Primary effusion lymphoma may affect HIV-negative elderly patients from Human Herpes virus 8 endemic regions. So far, rare cases have been reported in transplanted patients. The purpose of our systematic review is to improve our understanding of this type of aggressive lymphoma in the setting of transplantation, focusing on epidemiology, clinical presentation, pathological features, differential diagnosis, treatment and outcome. The role of assessing the viral serological status in donors and recipients is also discussed. METHODS: We performed a systematic review adhering to the PRISMA guidelines. The literature search was conducted on PubMed/MEDLINE, Web of Science, Scopus, EMBASE and Cochrane Library, using the search terms "primary effusion lymphoma" and "post-transplant". RESULTS: Our search identified 13 cases of post-transplant primary effusion lymphoma, predominantly in solid organ transplant recipients (6 kidney, 3 heart, 2 liver and 1 intestine), with only one case after allogenic bone marrow transplantation. Long-term immunosuppression is important in post-transplant primary effusion lymphoma commonly developing several years after transplantation. Kaposi Sarcoma occurred in association with lymphoma in 4 cases of solid organ recipients. The lymphoma showed the classical presentation with body cavity effusions in absence of tumor masses in 10 cases; 2 cases presented as solid masses, lacking effusions and one case as effusions associated with multiple organ involvement. Primary effusion lymphoma occurring in the setting of transplantation was more often Epstein Barr-virus negative. The prognosis was poor. In addition to chemotherapy, reduction of immunosuppressive treatment, was generally attempted. CONCLUSIONS: Primary effusion lymphoma is a rare, but often fatal post-transplant complication. Its rarity and the difficulty in achieving the diagnosis may lead to miss this complication. Clinicians should suspect primary effusion lymphoma in transplanted patients, presenting generally with unexplained body cavity effusions, although rare cases with solid masses are described.

One-instrument, objective microsatellite instability analysis using high-resolution melt.

In recent years, immune checkpoint inhibitors have proved immense clinical progression in the treatment of certain cancers. The efficacy of immune checkpoint inhibitors is correlated with mismatch repair system deficiency and is exceptionally administered based exclusively on this biological mechanism independent of the cancer type. The promising effect of immune checkpoint inhibitors has left an increasing demand for analytical tools evaluating the mismatch repair status. The analysis of microsatellite instability (MSI), reflecting an indirect but objective manner the inactivation of the mismatch repair system, plays several roles in clinical practice and, therefore, its evaluation is of high relevance. Analysis of MSI by PCR followed by fragment analysis on capillary electrophoresis remains the gold standard method for detection of a deficient mismatch repair system and thereby treatment with immune checkpoint inhibitors. Novel technologies have been applied and concepts such as tumor mutation burden have been introduced. However, to date, most of these technologies require high costs or the need of matched non-tumor tissue as internal comparator. In this study, we present a novel, one-instrument, fast, and objective method for the detection of MSI (MicroSight® MSI 1-step HRM Analysis), which does not depend on the use of matched non-tumor tissue. The assay analyzes five well-described mononucleotide microsatellite sequences by real-time PCR followed by high-resolution melt and evaluates microsatellite length variations via PCR product melting profiles. The assay was evaluated using two different patient cohorts and evaluation included several DNA extraction methodologies, two different PCR platforms, and an inter-laboratory ring study. The MicroSight® MSI assay showed a high repeatability regardless of DNA extraction method and PCR platform, and a 100% agreement of the MSI status with PCR fragment analysis methods applied as clinical comparator.

Apoptosis in thymus of teleost fish.

The presence and distribution of apoptotic cells during thymus development and in adult were studied by in situ end-labelling of fragmented DNA in three temperate species carp (Cyprinus carpio), sea bass (Dicentrarchus labrax) and dusky grouper (Epinephelus marginatus) and in the adult thymus of three Antarctic species belonging to the genus Trematomus spp. During thymus development some few isolated apoptotic cell (AC) firstly appeared in the central-external part of the organ (carp: 5 days ph; sea bass: 35 days ph grouper: 43 days ph). Initially the cells were isolated and then increased in number and aggregated in small groups in the outer-cortical region of the thymus larvae. The high density of apoptotic cells was observed in the junction between cortex and medulla from its appearance (border between cortex and medulla, BCM). ACs decreased in number in juveniles and adult as well as the ACs average diameter. In late juveniles and in adulthood, the apoptosis were restricted to the cortex. In Antarctic species the thymus is highly adapted to low temperature (high vascularisation to effort the circulation of glycoproteins enriched plasma and strongly compact parenchyma). The apoptosis process was more extended (4-7 fold) as compare with the thymus of temperate species, even if the distribution of ACs was similar in all examined species. Data suggested a common process of T lymphocyte negative-selection in BCM of thymus during the ontogeny. The selection process seems to be still active in adult polar fish, but restricted mainly in the cortex zone.

Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses.

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

Co-occurrence of JAK2-V617 F mutation and BCR::ABL1 translocation in chronic myeloproliferative neoplasms: a potentially confounding genetic combination.

Myeloproliferative neoplasms (MPNs) are classified into Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) and Ph-negative MPNs. BCR::ABL1 translocation is the key genetic event of CML, whereas JAK2/MPL/CALR mutations are molecular aberrations of Ph-negative MPNs. Despite initially considered mutually exclusive genetic aberrations, the co-occurrence of BCR::ABL1 and JAK2 has been reported in a limited number of cases. The two genetic alterations may be identified either at the same time or JAK2 aberration may be detected in patients with a previous CML treated with tyrosine kinase inhibitors or, finally, BCR::ABL1 translocation occurs in patients with a history of JAK2-positive MPN. This combination of genomic alterations is potentially confounding with clinical manifestations often misinterpreted either as disease progression or drug resistance, therefore leading to inappropriate patient's treatment. Our systematic review aims to improve hematologist and pathologist knowledge on this rare subset of patients. Starting from the presentation of two additional cases from our routine daily practice, we focus mainly on clinical, laboratory, and bone marrow histological findings, which may represent useful clues of BCR::ABL1 and JAK2 co-occurrence. The interaction between JAK2 and BCR::ABL1 clones during the disease course as well as therapy and outcome are presented.

Human neural stem cells drug product: Microsatellite instability analysis.

INTRODUCTION: In central nervous system neurodegenerative disorders, stem cell-based therapies should be considered as a promising therapeutic approach. The safe use of human Neural Stem Cells (hNSCs) for the treatment of several neurological diseases is currently under evaluation of phase I/II clinical trials. Clinical application of hNSCs require the development of GMP standardized protocols capable of generating high quantities of reproducible and well characterized stem cells bearing stable functional and genetic properties. AIM: The aim of this study was to evaluate possible instabilities or modifications of the microsatellite loci in different culture passages because high culture passages represent an in vitro replicative stress leading to senescence. Experimental method: The hNSCs were characterized at different culture time points, from passage 2 to passage 25, by genetic typing at ten microsatellite loci. CONCLUSION: We showed that genetic stability at microsatellite loci is maintained by the cells even at high passages adding a further demonstration of the safety of our hNSCs GMP culture method.

Pediatric Thymoma: A Review and Update of the Literature.

Pediatric thymomas are extremely rare and slow-growing malignant tumors. The recent publication of the first Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) Tumor-Node-Metastasis (TNM) stage classification and updated treatment guidelines for thymomas has prompted us to perform a review of the literature on pediatric thymomas. A search of English-language articles in the PubMed, Cochrane, Web of Science, and Embase databases was conducted. Additional articles were identified through reference lists of retrieved publications. Thirty-two articles involving 82 pediatric thymomas were included. Males comprised 60% of patients, and 13% manifested myasthenia gravis (MG). Histotype B1 (45%) and stage I (52% Masaoka-Koga and 71% UICC/AJCC TNM) were the most frequent. Of note is the possibility that the lack of cases with mixed histologies in the reviewed publications might be related to a sampling issue, as it is well known that the more sections are available for review, the more likely it is that the majority of these neoplasms will show mixed histologies. Both staging systems showed a gradual increase in the percentage of cases, with more advanced stages of disease moving from type A to B3 thymomas. Complete surgical resection (R0) was the main therapeutic approach in Masaoka-Koga stage I (89%) and UICC/AJCC TNM stage I (70%) thymomas. Advanced stages of disease and incomplete surgical resection were most often associated with recurrence and death. An association between stage and outcome, and completeness of resection and outcome, was found. Interestingly, though an association between histotype and staging was found, this does not take into account the possibility of mixed histologies which would reduce the clinical impact of histologic subtyping over staging.

Looking for a Simplified Diagnostic Model to Identify Potentially Lethal Cases of Prostate Cancer at Initial Diagnosis: An ImGO Pilot Study.

The recurrent genetic anomalies used to classify prostate cancer (PC) into distinct molecular subtypes have limited relevance for clinical practice. In consideration of WHO 2016 histological classification, which includes the introduction of Gleason Score 4 for patients with cribriform component and the definition of intraductal carcinoma as a new entity, a retrospective pilot study was conducted to investigate, by histological review, if there were any variations of Gleason Score and the incidence of intraductal carcinoma and cribriform pattern, intended as "phenotypic" markers of potentially lethal PC, among metastatic castration-sensitive PC (mCSPC) and metastatic castration-resistant PC (mCRPC) samples. Potentially predictive factors were also assessed. Among 125 cases, a variation in the Gleason Score was reported in 26% of cases. A cribriform (36%) or intraductal (2%) pattern was reported in a higher percentage. Of them, a primary Gleason pattern 4 was reported in 80% of cases. All patients with intraductal carcinoma present a BRCA2 mutation, also found in 80% of cases with a cribriform pattern. This pilot study documented some hypothesis-generating data, as the evaluation of de novo mCSPC and mCRPC as phenotypic/biologic model to be translated in clinical practice. A cribriform pattern/intraductal carcinoma might be a marker of potentially lethal PC. The high incidence of TP53 and BRCA2 mutations in de novo mCSPC may also have a therapeutic implication.

Indolent T-Cell Lymphoproliferative Disorders of the Gastrointestinal Tract (iTLPD-GI): A Review.

iTLPD-GI is a low-grade clonal T-cell lymphoproliferative disease arising in GI organs. It is an uncommon disease, and only recently has it been enlisted as a distinct provisional entity in the current WHO Classification. Data from the literature disclose high heterogeneity in terms of pathological and molecular features; on the other hand, establishing an accurate diagnosis of iTLPD-GI is of pivotal importance, since treatment options are different from that of other, more frequent lymphomas that arise in the gastrointestinal tract. In this review, we aimed to better define this novel entity, and to identify useful diagnostic biomarkers; moreover, we provide a biomarker-based approach to the diagnosis and describe the most common issues in differentiating iTLPD-GI from other neoplastic and non-neoplastic disorders.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 2).

Epstein-Barr virus (EBV) is a common pathogen infecting people primarily early in life. The virus has the ability to persist throughout a person's life, usually in B lymphocytes. Conditions of immunodeficiency as well as the introduction of immunosuppressive therapies and the advent of transplant technologies has brought immunodeficiency-associated lymphoproliferative disorders into view, which are often driven by EBV. The group of EBV-associated lymphoproliferative disorders includes different entities, with distinct biological features, ranging from indolent disorders, which may even spontaneously regress, to aggressive lymphomas requiring prompt and adequate treatment. These disorders are often diagnostically challenging due to their overlapping morphology and immunophenotype. Both nodal and extra-nodal sites, including the gastrointestinal tract, may be involved. This review, divided in three parts, summarizes the clinical, pathological, molecular features and treatment strategies of EBV-related lymphoproliferative disorders occurring in the gastrointestinal tract and critically analyzes the major issues in the differential diagnosis. In this part of the review, we discuss plasmablastic lymphoma, extra-cavitary primary effusion lymphoma and Burkitt lymphoma.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 1).

EBV is the most common persistent virus in humans. The interaction of EBV with B lymphocytes, which are considered the virus reservoir, is at the base of the life-long latent infection. Under circumstances of immunosuppression, the balance between virus and host immune system is altered and hence, EBV-associated lymphoid proliferations may originate. These disorders encompass several entities, ranging from self-limited diseases with indolent behavior to aggressive lymphomas. The virus may infect not only B-cells, but even T- and NK-cells. The occurrence of different types of lymphoid disorders depends on both the type of infected cells and the state of host immunity. EBV-driven lymphoproliferative lesions can rarely occur in the gastrointestinal tract and may be missed even by expert pathologists due to both the uncommon site of presentation and the frequent overlapping morphology and immunophenotypic features shared by different entities. The aim of this review is to provide a comprehensive overview of the current knowledge of EBV-associated lymphoproliferative disorders, arising within the gastrointestinal tract. The review is divided in three parts. In this part, the available data on EBV biology, EBV-positive mucocutaneous ulcer, EBV-positive diffuse large B-cell lymphoma, not otherwise specified and classic Hodgkin lymphoma are discussed.

Primary Pulmonary B-Cell Lymphoma: A Review and Update.

Primary pulmonary B-cell lymphomas (PP-BCLs) comprise a group of extranodal non-Hodgkin lymphomas of B-cell origin, which primarily affect the lung without evidence of extrapulmonary disease at the time of diagnosis and up to 3 months afterwards. Primary lymphoid proliferations of the lung are most often of B-cell lineage, and include three major entities with different clinical, morphological, and molecular features: primary pulmonary marginal zone lymphoma of mucosa-associated lymphoid tissue (PP-MZL, or MALT lymphoma), primary pulmonary diffuse large B cell lymphoma (PP-DLBCL), and lymphomatoid granulomatosis (LYG). Less common entities include primary effusion B-cell lymphoma (PEL) and intravascular large B cell lymphoma (IVLBCL). A proper workup requires a multidisciplinary approach, including radiologists, pneumologists, thoracic surgeons, pathologists, hemato-oncologists, and radiation oncologists, in order to achieve a correct diagnosis and risk assessment. Aim of this review is to analyze and outline the clinical and pathological features of the most frequent PP-BCLs, and to critically analyze the major issues in their diagnosis and management.

T-Cell Lymphoblastic Lymphoma Arising in the Setting of Myeloid/Lymphoid Neoplasms with Eosinophilia: LMO2 Immunohistochemistry as a Potentially Useful Diagnostic Marker.

BACKGROUND: Rarely, T-lymphoblastic lymphoma (T-LBL) may develop in the setting of myeloid/lymphoid neoplasms with eosinophilia (M/LNs-Eo), a group of diseases with gene fusion resulting in overexpression of an aberrant tyrosine kinase or cytokine receptor. The correct identification of this category has relevant therapeutic implications. LIM domain only 2 (LMO2) is overexpressed in most T-LBL, but not in immature TdT-positive T-cells in the thymus and in indolent T-lymphoblastic proliferations (iT-LBP). METHODS AND RESULTS: We retrospectively evaluated 11 cases of T-LBL occurring in the context of M/LNs-Eo. Clinical, histological, immunohistochemical and molecular features were collected and LMO2 immunohistochemical staining was performed. The critical re-evaluation of these cases confirmed the diagnosis of T-LBL with morphological, immunohistochemical and molecular features consistent with T-LBL occurring in M/LNs-Eo. Interestingly, LMO2 immunohistochemical analysis was negative in 9/11 cases, whereas only 2 cases revealed a partial LMO2 expression with a moderate and low degree of intensity, respectively. CONCLUSIONS: LMO2 may represent a potentially useful marker to identify T-LBL developing in the context of M/LNs-Eo. In this setting, T-LBL shows LMO2 immunohistochemical profile overlapping with cortical thymocytes and iT-LBP, possibly reflecting different molecular patterns involved in the pathogenesis of T-LBL arising in the setting of M/LNs-Eo.

Gastrointestinal Manifestations in Systemic Mastocytosis: The Need of a Multidisciplinary Approach.

Mastocytosis represents a heterogeneous group of neoplastic mast cell disorders. The basic classification into a skin-limited disease and a systemic form with multi-organ involvement remains valid. Systemic mastocytosis is a disease often hard to diagnose, characterized by different symptoms originating from either the release of mast cell mediators or organ damage due to mast cell infiltration. Gastrointestinal symptoms represent one of the major causes of morbidity, being present in 60-80% of patients. A high index of suspicion by clinicians and pathologists is required to reach the diagnosis. Gastrointestinal mastocytosis can be a challenging diagnosis, as symptoms simulate other more common gastrointestinal diseases. The endoscopic appearance is generally unremarkable or nonspecific and gastrointestinal mast cell infiltration can be focal and subtle, requiring an adequate sampling with multiple biopsies by the endoscopists. Special stains, such as CD117, tryptase, and CD25, should be performed in order not to miss the gastrointestinal mast cell infiltrate. A proper patient's workup requires a multidisciplinary approach including gastroenterologists, endoscopists, hematologists, oncologists, and pathologists. The aim of this review is to analyze the clinicopathological features of gastrointestinal involvement in systemic mastocytosis, focusing on the relevance of a multidisciplinary approach.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 3).

EBV is the first known oncogenic virus involved in the development of several tumors. The majority of the global population are infected with the virus early in life and the virus persists throughout life, in a latent stage, and usually within B lymphocytes. Despite the worldwide diffusion of EBV infection, EBV-associated diseases develop in only in a small subset of individuals often when conditions of immunosuppression disrupt the balance between the infection and host immune system. EBV-driven lymphoid proliferations are either of B-cell or T/NK-cell origin, and range from disorders with an indolent behavior to aggressive lymphomas. In this review, which is divided in three parts, we provide an update of EBV-associated lymphoid disorders developing in the gastrointestinal tract, often representing a challenging diagnostic and therapeutic issue. Our aim is to provide a practical diagnostic approach to clinicians and pathologists who face this complex spectrum of disorders in their daily practice. In this part of the review, the chronic active EBV infection of T-cell and NK-cell type, its systemic form; extranodal NK/T-cell lymphoma, nasal type and post-transplant lymphoproliferative disorders are discussed.

Differential molecular pathways expression in HER2 positive early breast cancer according to hormone receptor status.

PURPOSE: Hormone receptors (HR) status in HER2 + breast cancer (BC) is a recognized stratification factor with relevant clinical implication. According to HR expression, HER2 + BC show different clinical characteristics, treatment sensitivity and prognosis. The interaction between HR and HER2 pathways remains incompletely understood. METHODS: Thirty-four HER2 + BC were included: 18 tumors with HER2+/HR + and 16 with HER2+/HR-. The expression of 770 genes and 13 molecular pathways were evaluated using Nanostring PanCancer Pathway panel performed on FFPE BC biopsies. RESULTS: Gene expression analysis identified 127 genes with significantly different expression between the two cohorts. 83% of these genes were overexpressed in HER2+/HR- cohort. Globally, 23% of them belonged to PI3K pathway (41 genes), 15% to Trascriptional regulation (26 genes) and 12% to MAPK (22 genes). Regarding pathway expression, PI3K, MAPK and NOTCH were significantly differently expressed between the two groups (p = 0.003, p = 0.0018 and p = 0.02, respectively), all of them were overexpressed in HER2+/HR- tumors. CONCLUSIONS: According to HR status, HER2 + tumors express different pathways profiles: the overexpression of PI3K, MAPK and NOTCH pathways in HER2+/HR- group could justify different survival outcomes and treatment sensitivity. The identification of tumor driver pathways may be a useful instrument for individualized pathway-directed therapies. Further clinical implications are warranted.

Clinical Impact and Prognostic Role of KRAS/BRAF/PIK3CA Mutations in Stage I Colorectal Cancer.

Stage I colorectal carcinoma has excellent prognosis, with 5-year survival rate up to 95%. The occurrence of lymphovascular invasion, tumor budding, high number of PDC, or lymph node micrometastases is associated with tumor progression. The aim of this study was to evaluate the mutational status of 62 stage I colorectal carcinomas (CRC) (taken from 37 patients surviving more than five years since the initial diagnosis and from 25 patients who died of disease) and to correlate it with histopathological features and the clinical outcome. Mutations of KRAS, NRAS, BRAF, and PIK3CA genes were analyzed through Myriapod Colon Status Kit, using the high-throughput genotyping platform Sequenom MassARRAY System. Mutations in those genes were found in 31 cases (50%) and mainly in those with poor prognosis. The most frequent mutations occurred at codons 12 and 13 of the KRAS gene (40% of cases). We found concomitant PIK3CA mutations in 5 cases (8%). The presence of PIK3CA mutations was mainly observed in tumors with poor prognosis and with unfavorable histopathological prognostic features. High PDC grade (P = 0.0112), the presence of tumor budding (P = 0.0334), LVI (P < 0.0001), KRAS mutations (P = 0.0228), PIK3CA mutations (P = 0.0214), multiple genetic mutations in KRAS and PIK3CA genes (P = 0.039), and nodal micrometastases (P < 0.0001) were significant prognostic variables for CSS. The presence of LVI was the only independent and statistically significant prognostic variable for CSS in our cohort of pTNM stage I CRCs. The analysis of KRAS/PIK3CA mutational status may be used to identify patients with stage I CRC at high risk of bad outcome and who may need additional treatments, including biological therapies.

Clinical and molecular predictors of long-term response in HER2 positive metastatic breast cancer patients.

BACKGROUND: HER2+ metastatic breast cancer (MBC) is a poor prognosis disease, unusually curable. To date, no predictive factors have been clearly correlated with long-term response to anti-HER2 agents. METHODS: 54 HER2+ MBC patients treated with HER2 targeted therapy as first line treatment were analysed: 40 with a time to progression longer than 3 years in Long Responders (LR) group and 14 with a progression disease within one year of anti-HER2 therapy in a control group named Early Progressors (EP). The expression of 770 genes and 13 molecular pathways were evaluated using Nanostring PanCancer pathway panel performed on FFPE BC tissues. RESULTS: Considering baseline patients and tumor characteristics, EP women had more CNS spread and more metastatic burden of disease compared to LR (p > 0.05). Gene expression analysis identified 30 genes with significantly different expression in the two cohorts; five were driver genes (BRCA1, PDGFRA, AR, PHF6 and MSH2). The majority of these genes were over-expressed, mainly in LR patients, and encoded growth factors, pro- or anti-inflammatory interleukins and DNA repair factors. Only four genes were down regulated, all in EP group (TNFSF10, CACNG1, IL20RB and BRCA1). Most of these genes were involved in MAPK and PI3K pathways. MAPK pathway was differently expressed between LR and EP (p = 0.05). PI3K was the only pathway overexpressed in EP patients. CONCLUSIONS: Whole genome expression analysis comparing LR vs. EP identified a group of genes that may predict more favourable long-term outcomes. Up-regulation of MAPK and down-regulation of PI3K pathway could be a positive predictive factors. Further clinical implications are warranted. ABBREVIATIONS: BC: breast cancer; MBC: metastatic breast cancer; LR: long responder; EP: early progressor; FFPE: formalin-fixed paraffin-embedded; CNS: central nervous system; PFS: progression free survival; OS: overall survival.

Mutational Profile of Metastatic Breast Cancer Tissue in Patients Treated with Exemestane Plus Everolimus.

BACKGROUND: Everolimus has been shown to overcome endocrine resistance in hormone receptor positive advanced breast cancer patients. Predictive biomarkers of everolimus efficacy have been investigated in primary breast cancer tissue without finding univocal results. The goal of this study was to investigate the mutational burden in the metastatic site of endocrine-resistant tumors treated with everolimus plus exemestane. PATIENTS AND METHODS: Mass Array Sequenom platform was used to analyse genetic status of 18 cancer-related genes in 25 archival tumor specimens from metastatic lesions and available primary matched breast cancer tissue of patients treated with everolimus and exemestane for advanced disease. An exploratory analysis of everolimus efficacy in terms of progression free survival benefit and single gene mutation was carried out. RESULTS: The overall detection rate of mutation was 30% and 38% from metastatic and primary breast cancer samples, respectively. AKT1E17K was the most frequent mutated gene. No primary breast cancer and matched relapse maintained the same mutation profile. Considering molecular pathways, the most of the genes belong to PI3K pathway (AKT1E17K, PI3KCAE545K, and KITG565R,S709F). In patients with detected mutations in breast and/or recurrence tissue the median PFS was 5,6 months while in the subgroup of patients with no mutations the median PFS was 7,5 months. CONCLUSIONS: The mutational status of breast cancer recurrence allows the identification of some genes potentially correlating tumor response/resistance to everolimus. The most frequently mutated genes were involved in the PI3K/AKT/mTOR pathway highlighting that the deregulation of this pathway in the relapse plays a crucial role in the mechanisms of everolimus resistance/sensitivity. Owing to the small sample size and the retrospective nature of the study, these correlations need to be validated in a large prospective study.