Primary Cutaneous CD4+ Small/Medium T-Cell Lymphoproliferative Disorders (SMPLPD), demographical, clinical, therapeutic and prognostic aspects: a retrospective monocentric analysis.

Primary Cutaneous CD4+ Small/Medium T-Cell Lymphoproliferative Disorders (SMPLPD), also known as PCS-TCLPD, represent a rare group of hematologic diseases primarily affecting the skin. In this retrospective single-centre case series study, we aimed to investigate the demographic, clinical, therapeutic, and prognostic aspects of SMPLPD. We collected data from cases diagnosed between 2010 and the present, employing histopathological and immunohistochemical methods following WHO criteria. We included 22 patients with a median age of 61.50 years and median time between clinical onset and diagnosis of 3.00 months. Surgical excision with conservative margins was the primary choice, showing clinical remission in 17 cases, while non-surgical treatments, including radiotherapy, high-potency steroid treatment and ablative laser, achieved clinical remission in four cases. Clinical presentations varied, but the most common one was a single violaceous nodule/papule on upper body parts. In conclusion, our single-centre case series provides valuable insights into SMPLPD, highlighting the effectiveness of surgical treatments and the potential of non-surgical ones. Even if controversial, the benign nature of SMPLPD emphasizes the importance of achieving tumour clearance with acceptable aesthetic outcomes.

Genomic Profiling of Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System Suggests Novel Potential Therapeutic Targets.

Primary diffuse large B-cell lymphoma of the primary central nervous system (CNS-DLBCL) is an aggressive disease, with dismal prognosis despite the use of high-dose methotrexate-based polychemotherapy. Our study aimed to expand the biologic profiles of CNS-DLBCL and to correlate them with clinical/imaging findings to gain diagnostic insight and possibly identify new therapeutic targets. We selected 61 CNS-DLBCL whose formalin-fixed paraffin-embedded samples were available at first diagnosis. These were investigated by immunohistochemistry, cMYC rearrangements were explored by fluorescence in situ hybridization, and CNS-DLBCL mutated genes were evaluated by next-generation sequencing. CD10, BCL6, and IRF4 were observed in 16%, 83.6%, and 93% of cases, respectively. As typical of CNS lymphoma, 10 (16.4%) of 61 cases were classified as germinal center (GCB) type and 51 (83.6%) of 61 as non-germinal center (non-GCB) type according to the Hans algorithm. Double-expression status for BCL2 and cMYC was detected in 36 (59%) of 61 cases whereas 25 (41%) of 61 were non-DE. Rearrangement of the cMYC gene was detected in 2 cases, associated with BCL6 translocation only in 1 case MYD88, PIM1, CD79B, and TP53 were mutated in 54.5%, 53.5%, 30.2%, and 18.4% cases, respectively. Novel mutations not previously reported in CNS-DLBCL were found: AIP in 23.1%, PI3KCA in 15%, NOTCH1 in 11.4%, GNAS in 8.1%, CASP8 in 7.9%, EGFR in 6.4%, PTEN in 5.1, and KRAS in 2.6% of cases. Survival was significantly longer for patients with mutated MYD88 (8.7 months vs 1.7 months; log-rank test = 5.43; P = .020) and for patients with mutated CD79B (10.8 months vs 2.5 months; log-rank test = 4.64; P = .031). MYD88 and CD79B predicted a longer survival in patients affected by CNS-DLBCL. Notably, we identified novel mutations that enrich the mutational landscape of CNS-DLBCL, suggest a role of PTEN-PI3K-AKT and receptor tyrosine kinase-RAS-mitogen-activated protein kinase signaling in a subset of CNS-DLBCL, and provide new potential therapeutic targets.

Massive parallel sequencing unveils homologous recombination deficiency in follicular dendritic cell sarcoma.

Standardized treatment options are lacking for patients with unresectable or multifocal follicular dendritic cell sarcoma (FDCS) and disease-related mortality is as high as 20%. Applying whole genome sequencing (WGS) in one case and whole exome sequencing (WES) in additional twelve, this study adds information on the molecular landscape of FDCS, expanding knowledge on pathobiological mechanisms and identifying novel markers of potential theragnostic significance. Massive parallel sequencing showed high frequency of mutations on oncosuppressor genes, particularly in RB1, CARS and BRCA2 and unveiled alterations on homologous recombination DNA damage repair related genes in 70% (9/13) of cases. This indicates that patients with high stage FDCS may be eligible for poly ADP ribose polymerase inhibition protocols. Low tumor mutational burden was confirmed in this study despite common PDL1 expression in FDCS arguing on the efficacy of immune checkpoint inhibitors. CDKN2A deletion, detected by WGS and confirmed by FISH in 41% of cases (9/22) indicates that impairment of cell cycle regulation may sustain oncogenesis in FDCS. Absence of mutations in the RAS/RAF/MAPK pathway and lack of clonal hematopoiesis related mutations in FDCS sanction its differences from dendritic cell-derived neoplasms of haematopoietic derivation. WGS and WES in FDCS provides additional information on the molecular landscape of this rare tumor, proposing novel candidate genes for innovative therapeutical approaches to improve survival of patients with multifocal disease.

Follicular Lymphoma Microenvironment Traits Associated with Event-Free Survival.

The majority of patients with Follicular Lymphoma (FL) experience subsequent phases of remission and relapse, making the disease "virtually" incurable. To predict the outcome of FL patients at diagnosis, various clinical-based prognostic scores have been proposed; nonetheless, they continue to fail for a subset of patients. Gene expression profiling has highlighted the pivotal role of the tumor microenvironment (TME) in the FL prognosis; nevertheless, there is still a need to standardize the assessment of immune-infiltrating cells for the prognostic classification of patients with early or late progressing disease. We studied a retrospective cohort of 49 FL lymph node biopsies at the time of the initial diagnosis using pathologist-guided analysis on whole slide images, and we characterized the immune repertoire for both quantity and distribution (intrafollicular, IF and extrafollicular, EF) of cell subsets in relation to clinical outcome. We looked for the natural killer (CD56), T lymphocyte (CD8, CD4, PD1) and macrophage (CD68, CD163, MA4A4A)-associated markers. High CD163/CD8 EF ratios and high CD56/MS4A4A EF ratios, according to Kaplan-Meier estimates were linked with shorter EFS (event-free survival), with the former being the only one associated with POD24. In contrast to IF CD68+ cells, which represent a more homogeneous population, higher in non-progressing patients, EF CD68+ macrophages did not stratify according to survival. We also identify distinctive MS4A4A+CD163-macrophage populations with different prognostic weights. Enlarging the macrophage characterization and combining it with a lymphoid marker in the rituximab era, in our opinion, may enable prognostic stratification for low-/high-grade FL patients beyond POD24. These findings warrant validation across larger FL cohorts.

ETV6::ABL1-Positive Myeloid Neoplasm: A Case of a Durable Response to Imatinib Mesylate without Additional or Previous Treatment.

ETV6::ABL1 rearranged neoplasms are rare hematological diseases. To date, about 80 cases have been reported, including myeloid and lymphoid leukemias. The ETV6 gene codes for an ETS family transcription factor and several fusion partners have been described. When translocated, ETV6 causes the constitutive activation of the partner genes. Here, we report the case of a 54-year-old woman with a cryptic insertion of the 3' region of ABL1 in the ETV6 gene. The patient was first diagnosed with idiopathic hypereosinophilic syndrome, according to the clinical history, conventional cytogenetics, standard molecular analyses and pathologist description. Next generation sequencing of diagnosis samples unexpectedly detected both ETV6::ABL1 type A and B fusion transcripts, which were then confirmed by FISH. The diagnosis was Myeloid/Lymphoid neoplasm with ETV6::ABL1 fusion, and the patient received imatinib mesylate treatment. In a follow-up after more than one year, the patient still maintained the molecular and complete hematological responses. This case highlights the importance of timely and proper diagnostics and prompt tyrosine kinase inhibitor treatment.

Prognostic impact of TP53 mutation in newly diagnosed diffuse large B-cell lymphoma patients treated in the FIL-DLCL04 trial.

The prognostic role of TP53 disruption has been established in diffuse large B-cell lymphoma (DLBCL). Aim of this analysis was to correlate TP53 mutations by Sanger sequencing, cell of origin (COO) profile by Lymph2Cx panel on the NanoString platform and MYC, BCL2 and BCL6 overexpression or re-arrangements by immunohistochemistry (IHC) and fluorescent in-situ hybridization (FISH), with outcome in DLBCL patients enrolled into the FIL-DLCL04 trial (NCT00499018). One hundred and twenty-five DLBCL patients with tumour block available were analyzed. TP53 was mutated in 11/125 (9%) cases; 60/125 patients received high-dose chemoimmunotherapy up-front, as for the randomization arm; COO was reported in 88 patients: 48 germinal centre B-cell like, 25 activated B-cell like and 17 unclassified; 26 patients were double expressors in IHC and 11 double hit in FISH. After a median follow-up of 72 months, five-year failure-free survival (FFS) for TP53 mutated versus wild-type was 24% and 72%, and five-year overall survival (OS) was 34% and 83%, respectively. Adjusted hazard ratio (HR) was 2·28 [95% confidence interval (CI) 0·89-5·86, p = 0·086] and 4·05 (95% CI 1·37-11·97, p = 0·011) for FFS and OS, respectively. In this series of young DLBCL patients, TP53 gene mutation identified a poor prognosis subgroup, regardless of treatment and other biological markers.

Burkitt lymphoma with a granulomatous reaction: an M1/Th1-polarised microenvironment is associated with controlled growth and spontaneous regression.

AIMS: Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that, in some instances, may show a granulomatous reaction associated with a favourable prognosis and occasional spontaneous regression. In the present study, we aimed to define the tumour microenvironment (TME) in four such cases, two of which regressed spontaneously. METHODS AND RESULTS: All cases showed aggregates of tumour cells with the typical morphology, molecular cytogenetics and immunophenotype of BL surrounded by a florid epithelioid granulomatous reaction. All four cases were Epstein-Barr virus (EBV)-positive with type I latency. Investigation of the TME showed similar features in all four cases. The analysis revealed a proinflammatory response triggered by Th1 lymphocytes and M1 polarised macrophages encircling the neoplastic cells with a peculiar topographic distribution. CONCLUSIONS: Our data provide an in-vivo picture of the role that specific immune cell subsets might play during the early phase of BL, which may be capable of maintaining the tumour in a self-limited state or inducing its regression. These novel results may provide insights into new potential therapeutic avenues in EBV-positive BL patients in the era of cellular immunotherapy.

Droplet digital polymerase chain reaction for the assessment of disease burden in hairy cell leukemia.

BRAFV600E mutation is the pathogenic driver of hairy cell leukemia (HCL) found in the vast majority of cases both at onset and during recurrences. The identification of the mutated allele in blood and marrow correlates with the presence of neoplastic cells and can be considered a marker of active disease. Likewise, the absence of the mutation after treatment may indicate a state of deep response. The BRAFV600E burden was measured by droplet digital polymerase chain reaction (ddPCR) and expressed as fractional abundance in 35 HCL patients at different stages of disease (onset, relapse, complete response [CR] after treatment, long-term remission) in peripheral blood and/or bone marrow (when available). Mean values of fractional abundance for patients at diagnosis, relapse and response, respectively, were 12.26%, 16.52% and 0.02% in peripheral blood and 23.51%, 13.96% and 0.26% in bone marrow. Four patients out of 6 evaluated at response were molecularly negative for BRAFV600E in peripheral blood. Mean fractional abundance in peripheral blood tested in 14 patients with long lasting CR was 0.05%, and 10 patients were BRAFV600E negative. These preliminary results suggest that ddPCR permits to assess the active tumor burden in HCL at different disease phases and support the hypothesis that some patients in CR qualify for a molecular CR.

NR1H3 (LXRα) is associated with pro-inflammatory macrophages, predicts survival and suggests potential therapeutic rationales in diffuse large b-cell lymphoma.

The role of macrophages (Mo) and their prognostic impact in diffuse large B-cell lymphomas (DLBCL) remain controversial. By regulating the lipid metabolism, Liver-X-Receptors (LXRs) control Mo polarization/inflammatory response, and their pharmacological modulation is under clinical investigation to treat human cancers, including lymphomas. Herein, we surveyed the role of LXRs in DLBCL for prognostic purposes. Comparing bulk tumors with purified malignant and normal B-cells, we found an intriguing association of NR1H3, encoding for the LXR-α isoform, with the tumor microenvironment (TME). CIBERSORTx-based purification on large DLBCL datasets revealed a high expression of the receptor transcript in M1-like pro-inflammatory Mo. By determining an expression cut-off of NR1H3, we used digital measurement to validate its prognostic capacity on two large independent on-trial and real-world cohorts. Independently of classical prognosticators, NR1H3high patients displayed longer survival compared with NR1H3low cases and a high-resolution Mo GEP dissection suggested a remarkable transcriptional divergence between subgroups. Overall, our findings indicate NR1H3 as a Mo-related biomarker identifying patients at higher risk and prompt future preclinical studies investigating its mouldability for therapeutic purposes.

Reproducing the molecular subclassification of peripheral T-cell lymphoma-NOS by immunohistochemistry.

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of mature T-cell malignancies; approximately one-third of cases are designated as PTCL-not otherwise specified (PTCL-NOS). Using gene-expression profiling (GEP), we have previously defined 2 major molecular subtypes of PTCL-NOS, PTCL-GATA3 and PTCL-TBX21, which have distinct biological differences in oncogenic pathways and prognosis. In the current study, we generated an immunohistochemistry (IHC) algorithm to identify the 2 subtypes in paraffin tissue using antibodies to key transcriptional factors (GATA3 and TBX21) and their target proteins (CCR4 and CXCR3). In a training cohort of 49 cases of PTCL-NOS with corresponding GEP data, the 2 subtypes identified by the IHC algorithm matched the GEP results with high sensitivity (85%) and showed a significant difference in overall survival (OS) (P = .03). The IHC algorithm classification showed high interobserver reproducibility among pathologists and was validated in a second PTCL-NOS cohort (n = 124), where a significant difference in OS between the PTCL-GATA3 and PTCL-TBX21 subtypes was confirmed (P = .003). In multivariate analysis, a high International Prognostic Index score (3-5) and the PTCL-GATA3 subtype identified by IHC were independent adverse predictors of OS (P = .0015). Additionally, the 2 IHC-defined subtypes were significantly associated with distinct morphological features (P < .001), and there was a significant enrichment of an activated CD8+ cytotoxic phenotype in the PTCL-TBX21 subtype (P = .03). The IHC algorithm will aid in identifying the 2 subtypes in clinical practice, which will aid the future clinical management of patients and facilitate risk stratification in clinical trials.

A three-gene signature based on MYC, BCL-2 and NFKBIA improves risk stratification in diffuse large B-cell lymphoma.

Recent randomized trials focused on gene expression-based determination of the cell of origin in diffuse large B-cell lymphoma could not show significant improvements by adding novel agents to standard chemoimmunotherapy. The aim of this study was the identification of a gene signature able to refine current prognostication algorithms and applicable to clinical practice. Here we used a targeted gene expression profiling panel combining the Lymph2Cx signature for cell of origin classification with additional targets including MYC, BCL-2 and NFKBIA, in 186 patients from 2 randomized trials (discovery cohort) (NCT00355199 and NCT00499018). Data were validated in 3 independent series (2 large public datasets and a real-life cohort). By integrating the cell of origin, MYC/BCL-2 double expressor status and NFKBIA expression, we defined a 3-gene signature combining MYC, BCL-2 and NFKBIA (MBN-signature), which outperformed the MYC/BCL-2 double expressor status in multivariate analysis, and allowed further risk stratification within the germinal center B-cell/unclassified subset. The high-risk (MBN Sig-high) subgroup identified the vast majority of double hit cases and a significant fraction of Activated B-Cell-derived diffuse large B-cell lymphomas. These results were validated in 3 independent series including a cohort from the REMoDL-B trial, where, in an exploratory ad hoc analysis, the addition of bortezomib in the MBN Sig-high subgroup provided a progression free survival advantage compared with standard chemoimmunotherapy. These data indicate that a simple 3-gene signature based on MYC, BCL-2 and NFKBIA could refine the prognostic stratification in diffuse large B-cell lymphoma, and might be the basis for future precision-therapy approaches.

Correction: Whole exome sequencing reveals mutations in FAT1 tumor suppressor gene clinically impacting on peripheral T-cell lymphoma not otherwise specified.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Whole exome sequencing reveals mutations in FAT1 tumor suppressor gene clinically impacting on peripheral T-cell lymphoma not otherwise specified.

Peripheral T-cell lymphoma not otherwise specified represents a diagnostic category comprising clinically, histologically, and molecularly heterogeneous neoplasms that are poorly understood. The genetic landscape of peripheral T-cell lymphoma not otherwise specified remains largely undefined, only a few sequencing studies having been conducted so far. In order to improve our understanding of the genetics of this neoplasm, we performed whole exome sequencing along with RNA-sequencing in a discovery set of 21 cases. According to whole exome sequencing results and mutations previously reported in other peripheral T-cell lymphomas, 137 genes were sequenced by a targeted deep approach in 71 tumor samples. In addition to epigenetic modifiers implicated in all subtypes of T-cell neoplasm (TET2, DNMT3A, KMT2D, KMT2C, SETD2), recurrent mutations of the FAT1 tumor suppressor gene were for the first time recorded in 39% of cases. Mutations of the tumor suppressor genes LATS1, STK3, ATM, TP53, and TP63 were also observed, although at a lower frequency. Patients with FAT1 mutations showed inferior overall survival compared to those with wild-type FAT1. Although peripheral T-cell lymphoma not otherwise specified remains a broad category also on molecular grounds, the present study highlights that FAT1 mutations occur in a significant proportion of cases, being provided with both pathogenetic and prognostic impact.

Post-radiotherapy vascular lesions of the breast: immunohistochemical and molecular features of 74 cases with long-term follow-up and literature review.

AIMS: A wide range of post-radiotherapy (RT) vascular lesions can occur, ranging from benign lymphangiomatous papules of the skin (BLAPs), to atypical vascular lesions (AVLs) and post-RT angiosarcomas (ASs). The relationship between benign and malignant post-RT breast lesions and their prognostic features are still controversial. The aims of this study were to investigate the relationship between benign and malignant mammary post-RT vascular lesions and to define post-RT AS prognostic features. METHODS AND RESULTS: Seventy-four post-RT vascular lesion cases were obtained and stained with antibodies against CD34, CD31, D2-40, Ki67, and c-Myc. Mutational analysis was performed by deep sequencing for the following genes: KRAS, NRAS, HRAS, BRAF, PIK3CA, TP53, NOTCH1, PTEN, CDKN2A, EGFR, AKT1, CTNNB1, hTERT, and PTPRB. Post-RT AS cases were graded according to a previously reported breast AS grading system. AVL cases showed a low number of HRAS and hTERT mutations, whereas post-RT AS cases showed a high frequency of EGFR, TP53, HRAS and hTERT mutations. On follow-up, all BLAP and AVL patients were alive with no evidence of disease. Post-RT AS 5-year overall survival declined with the increase in grade, as follows: 85.7% for grade 1, 83.3% for grade 2, and 40.4% for grade 3. CONCLUSIONS: Our findings confirm that BLAP and AVL have a good prognosis, and that post-RT AS prognosis is strongly related to histological grading. On molecular analysis, AVL and post-RT AS shared HRAS and hTERT mutations, suggesting a relationship between the two lesions.

Deregulation of miRNAs-cMYC circuits is a key event in refractory celiac disease type-2 lymphomagenesis.

A percentage of celiac disease (CD) patients develop refractory type-2 disease (RCD2), a condition associated with increased risk of enteropathy-associated T-cell-lymphoma (EATL) and without therapeutic option. Therefore, we profiled the miRNome in series of peripheral T-cell lymphomas (PTCLs), CD, RCD1 or 2 and in the murine interleukin-15 (IL15)-transgenic (TG) model of RCD. The transcriptome was analyzed in 18 intestinal T-cell lymphomas (ITLs). Bioinformatics pipelines provided significant microRNA (miRNA) lists and predicted targets that were confirmed in a second set of patients. Our data show that ITLs have a unique miRNA profile with respect to other PTCLs. The c-MYC regulated miR-17/92 cluster distinguishes monomorphic epitheliotropic ITL (MEITL) from EATL and prognosticates EATL outcome. These miRNAs are decreased in IL15-TG mice upon Janus kinase (JAK) inhibition. The random forest algorithm identified a signature of 38 classifier miRNAs, among which, the miR-200 and miR-192/215 families were progressively lost in RCD2 and ITL-CD, whereas miR-17/92 and C19MC miRNAs were up-regulated. Accordingly, SMAD3, MDM2, c-Myc and activated-STAT3 were increased in RCD2 and EATL tissues while JAK inhibition in IL15-TG mice restored their levels to baseline. Our data suggest that miRNAs circuit supports activation of STAT3 and c-Myc oncogenic signaling in RCD2, thus contributing to lymphomagenesis. This novel understanding might pave the way to personalized medicine approaches for RCD and EATL.

Cutaneous adverse-events in patients treated with Ibrutinib.

Ibrutinib is a Burton tyrosine kinase inhibitor (BTKi) approved for the treatment of several hematologic malignancies. Analyze skin adverse events (SAE). All the patients treated with Ibrutinib featuring cutaneous adverse events were selected. Twenty five patients were retrieved with a median interval between Ibrutinib start and SAE time of onset of 120 days. Most common SAE observed involved hairs and nails. Eczematous reaction and leucocytoclastic vasculitis were also detected. One patient had a long-history Ibrutinib treatment and experienced numerous cutaneous adverse events. Infective disease such as superficial mycosis and impetigo were rarely present in our series. Despite the development of cutaneous SAE, all the patients continued their concomitant drugs without the onset of any further SAE. Our data suggest Ibrutinib-associated rash should be distinguished in early and late events and a careful dermatologic management of patients should be scheduled.

CD30 expression in neoplastic T cells of follicular T cell lymphoma is a helpful diagnostic tool in the differential diagnosis of Hodgkin lymphoma.

Follicular T cell lymphoma is derived from follicular T-helper cells. In many cases, neoplastic T cells form rosettes around Hodgkin-Reed-Sternberg-like cells, which can lead to the misdiagnosis of classical Hodgkin lymphoma. The aim of the present study was to obtain a better understanding of this rosetting phenomenon and to recognize features that are helpful in the differential diagnosis of classical Hodgkin lymphoma. Sixteen mostly elderly follicular T cell lymphoma patients (mean 66 years) were analyzed. Fifteen of the 16 follicular T cell lymphoma cases presented with Hodgkin-Reed-Sternberg-like cells, which were CD20-positive in 27% of the cases and Epstein-Barr virus-infected in nearly all cases. Frequently, the immunophenotype of rosetting neoplastic T cells differed from the bulk neoplastic cells with less numerous T-follicular helper cell markers expressed, suggesting a modulation of T-follicular helper cell marker expression in the neoplastic T cells. In 75% of the cases, variable CD30 expression was encountered in the neoplastic T cells, likely reflecting an activation state in these cells. Hodgkin-Reed-Sternberg-like cells were positive for CCL17, and follicular T cell lymphoma tumor cells expressed its receptor CCR4 at variable intensity, thus potentially explaining the phenomenon of the tumor cells' rosetting around Hodgkin-Reed-Sternberg-like cells. In summary, this study confirms the presence of Hodgkin-Reed-Sternberg-like cells in a high number of cases of follicular T cell lymphoma, suggesting that Hodgkin-Reed-Sternberg-like cells may contribute to the development of this lymphoma. Hodgkin-Reed-Sternberg-like cells in follicular T cell lymphoma cannot reliably be differentiated from the Hodgkin-Reed-Sternberg cells of classical Hodgkin lymphoma based on their immunophenotype. In contrast, demonstration of a T-follicular helper cell phenotype with CD10 and frequent CD30 expression in the neoplastic T cell population can help to establish the diagnosis of follicular T cell lymphoma, and may even indicate CD30 as a therapeutic target for these patients.

PD-1 (PDCD1) promoter methylation in Merkel cell carcinoma: prognostic relevance and relationship with clinico-pathological parameters.

Merkel cell carcinoma is an aggressive neuroendocrine skin tumor, for which several non-conclusive prognostic factors of adverse clinical behavior have been reported. As promoter methylation of the immune checkpoint receptor CD279/PD-1/PDCD1(mPDCD1) has been shown to be a prognostic factor in different cancers, we investigated its role in Merkel cell carcinoma. mPDCD1was assessed retrospectively in a cohort of 69 Merkel cell carcinoma patients from the University of Bologna, University of Turin and University of Insubria. Kaplan-Meier curves and log-rank tests were calculated for all variables. To assess the influence of mPDCD1, the Cox proportional hazards model and different Royston-Parmar models were evaluated. High PDCD1 methylation (mPDCD1high) was associated with a higher overall mortality at both the univariate analysis (log rank test: χ2 = 5.17, p = 0.023; permutation test: p = 0.023) and the multivariate analysis (HR = 2.111, p = 0.042). The other variables associated with a higher overall mortality at the multivariate analysis were clinical stage III-IV (HR = 2.357, p = 0.008), size > 2 cm (HR = 2.248, p = 0.031) and Merkel cell polyomavirus (HR = 0.397, p = 0.015). Further, mPDCD1high was strongly associated with older age (81 vs 76 years, p = 0.042), absence of immune cells (92.6%, p < 0.001), no expression of PD-L1 by immune cells (70.4%, p = 0.041) and by both immune and tumor cells (70.4%, p = 0.001). mPDCD1 is a valid prognostic parameter in patients affected by Merkel cell carcinoma. In addition, it could provide an estimate of the global PD-1/PD-L1 expression with potentially relevant implications from a therapeutic point of view.

Blastic plasmacytoid dendritic cell neoplasm: genomics mark epigenetic dysregulation as a primary therapeutic target.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy for which there is still no effective therapy. In order to identify genetic alterations useful for a new treatment design, we used whole-exome sequencing to analyze 14 BPDCN patients and the patient-derived CAL-1 cell line. The functional enrichment analysis of mutational data reported the epigenetic regulatory program to be the most significantly undermined (P<0.0001). In particular, twenty-five epigenetic modifiers were found mutated (e.g. ASXL1, TET2, SUZ12, ARID1A, PHF2, CHD8); ASXL1 was the most frequently affected (28.6% of cases). To evaluate the impact of the identified epigenetic mutations at the gene-expression and Histone H3 lysine 27 trimethylation/acetylation levels, we performed additional RNA and pathology tissue-chromatin immunoprecipitation sequencing experiments. The patients displayed enrichment in gene signatures regulated by methylation and modifiable by decitabine administration, shared common H3K27-acetylated regions, and had a set of cell-cycle genes aberrantly up-regulated and marked by promoter acetylation. Collectively, the integration of sequencing data showed the potential of a therapy based on epigenetic agents. Through the adoption of a preclinical BPDCN mouse model, established by CAL-1 cell line xenografting, we demonstrated the efficacy of the combination of the epigenetic drugs 5'-azacytidine and decitabine in controlling disease progression in vivo.

Minimal residual disease (MRD) in non-Hodgkin lymphomas: Interlaboratory reproducibility on marrow samples with very low levels of disease within the FIL (Fondazione Italiana Linfomi) MRD Network.

In 2009, the four laboratories of the Fondazione Italiana Linfomi (FIL) minimal residual disease (MRD) Network started a collaborative effort to harmonize and standardize their methodologies at the national level, performing quality control (QC) rounds for follicular lymphoma (FL) and mantle cell lymphoma (MCL) MRD assessment. In 16 QC rounds between 2010 and 2017, the four laboratories received 208 bone marrow (BM) samples (126 FL; 82 MCL); 187 were analyzed, according to the EuroMRD Consortium guidelines, by both nested (NEST) polymerase chain reaction (PCR) and real-time quantitative (RQ) PCR for BCL2/IGH MBR or IGHV rearrangements. Here, we aimed at analyzing the samples that challenged the interlaboratory reproducibility and data interpretation. Overall, 156/187 BM samples (83%) were concordantly classified as NEST+/RQ+ or NEST-/RQ- by all the four laboratories. The remaining 31 samples (17%) resulted alternatively positive and negative in the interlaboratory evaluations, independently of the method and the type of rearrangement, and were defined "borderline" (brd) samples: 12 proved NEST brd/RQ brd, 7 NEST-/RQ brd, 10 NEST brd/RQ positive not quantifiable (PNQ), and 2 NEST brd/RQ-. Results did not change even increasing the number of replicates/sample. In 6/31 brd samples, droplet digital PCR (ddPCR) was tested and showed no interlaboratory discordance. Despite the high interlaboratory reproducibility in the MRD analysis obtained and maintained by the QC round strategy, samples with the lowest MRD levels can still represent a challenge: 17% (31/187) of our samples showed discordant results in interlaboratory assessments, with 6.4% (12/187) remained brd even applying the two methods. Thus, although representing a minority, brd samples are still problematic, especially when a clinically oriented interpretation of MRD results is required. Alternative, novel methods such as ddPCR and next-generation sequencing have the potential to overcome the current limitations.