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Neuroendocrine carcinomas are very aggressive tumors with few treatment options. DLL3 seems to be an optimal target for therapeutic intervention, as it is expressed mainly on the membrane of tumor cells with neuroendocrine origin.In this article, we outline the preclinical and clinical studies published in the last years on DLL3 in neuroendocrine neoplasm, above all of lung origin. Furthermore, we review the current literature on the interaction between DLL3 and the tumor microenvironment.Several DLL3-targeting strategies have been proposed in the last years with mixed results. Understanding the influence of DLL3 on the tumor (immune) microenvironment and developing adoptive therapies directed against this optimal target might represent the key strategy. Building on the clinical data obtained so far, future trials on in vivo diagnostic tools for predictive purpose and new specific therapies are needed.

Immune-checkpoint inhibitors (ICIs) have widened the therapeutic scenario of different cancer types. Phase I/II trials have been designed to evaluate the role of ICIs both as single agents and in combination in neuroendocrine neoplasms (NENs), but as yet no randomized controlled phase III trials have been carried out. A systematic review and meta-analysis of studies published could help to reduce the biases of single-phase II trials. Efficacy data were obtained on 636 patients. Pooled percentages of the overall response rate (ORR) and disease control rate (DCR) were 10% (95% CI: 6–15%, I2 = 67%, p < 0.1) and 42% (95% CI: 28–56%, I2 = 93%, p < 0.1), respectively. Median progression-free survival (mPFS) was 4.1 months (95% CI 2.6–5.4; I2 = 96%, p < 0.1) and median overall survival (mOS) was 11 months (95% CI 4.8–21.1; I2 = 98%, p < 0.1). Among the ICIs used as single agents, the anti-PD1 toripalimab achieved the highest ORR. Combination regimens were superior to monotherapy, e.g., the ICI combination nivolumab + ipilimumab, and the ICI + anti-angiogenetic combination atezolizumab + bevacizumab, both of which warrant further investigation. Promising efficacy and a good safety profile of ICIs represent a valid opportunity for expanding the therapeutic landscape of NENs. Predictive biomarkers are needed to identify the most suitable candidates for these regimens.

Pancreatic neuroendocrine tumors (PanNENs) are rare sporadic cancers or develop as part of hereditary syndromes. PanNENs can be both functioning and non-functioning based on whether they produce bioactive peptides. Some PanNENs are well differentiated while others—poorly. Symptoms, thus, depend on both oncological and hormonal causes. PanNEN diagnosis and treatment benefit from and in some instances are guided by biomarker monitoring. However, plasmatic monoanalytes are only suggestive of PanNEN pathological status and their positivity is typically followed by deepen diagnostic analyses through imaging techniques. There is a strong need for new biomarkers and follow-up modalities aimed to improve the outcome of PanNEN patients. Liquid biopsy follow-up, i.e., sequential analysis on tumor biomarkers in body fluids offers a great potential, that need to be substantiated by additional studies focusing on the specific markers and the timing of the analyses. This review provides the most updated panorama on PanNEN biomarkers.

Immunotherapy is the most promising therapeutic approach against malignant pleural mesothelioma (MPM). Despite technological progress, the number of targetable antigens or specific antibodies is limited, thus hindering the full potential of recent therapeutic interventions. All possibilities of finding new targeting molecules must be exploited. The specificity of targeting is guaranteed by the use of monoclonal antibodies, while fully human antibodies are preferred, as they are functional and generate no neutralizing antibodies. The aim of this review is to appraise the latest advances in screening methods dedicated to the identification and harnessing of fully human antibodies. The scope of identifying useful molecules proceeds along two avenues, i.e., through the antigen-first or binding-first approaches. The first relies on screening human antibody libraries or plasma from immunized transgenic mice or humans to isolate binders to specific antigens. The latter takes advantage of specific binding to tumor cells of antibodies present in phage display libraries or in responders’ plasma samples without prior knowledge of the antigens. Additionally, next-generation sequencing analysis of B-cell receptor repertoire pre- and post-therapy in memory B-cells from responders allows for the identification of clones expanded and matured upon treatment. Human antibodies identified can be subsequently reformatted to generate a plethora of therapeutics like antibody-drug conjugates, immunotoxins, and advanced cell-therapeutics such as chimeric antigen receptor-transduced T-cells.

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the pleural surface associated with asbestos exposure. The median survival of MPM patients is a mere 8-14 months, and there are few biomarkers and no cure available. It is hoped that, eventually, the incidence of MPM will drop and remain low and constant, given that most nations have banned the use of asbestos, but in the meantime, the incidence in Europe is still growing. The exact molecular mechanisms that explain the carcinogenicity of asbestos are not known. Standard therapeutic strategies for MPM include surgery, often coupled with chemotherapy and/or radiotherapy, in a small percentage of eligible patients and chemotherapy in tumors considered unresectable with or without adjuvant radiotherapy. In recent years, several new therapeutic avenues are being explored. These include angiogenesis inhibitors, synthetic lethal treatment, miRNA replacement, oncoviral therapies, and the fast-growing field of immunotherapy alone or in combination with chemotherapy. Of particular promise are the multiple options offered by immunotherapy: immune checkpoint inhibitors, tumor vaccines, and therapies taking advantage of tumor-specific antigens, such as specific therapeutic antibodies or advanced cell-based therapies exemplified by the CAR-T cells. This review comprehensively presents both old and new therapeutic options in MPM, focusing on the results of the numerous recent and on-going clinical trials in the field, including the latest data presented at international meetings (AACR, ASCO, and ESMO) this year, and concludes that more work has to be done in the framework of tailored therapies to identify reliable targets and novel biomarkers to impact MPM management.

Prostate cancer (PCa) patients are risk-stratified on the basis of clinical stage and PSA level at diagnosis and the Gleason Score (GS) in prostate biopsy. However, these parameters are not completely accurate in discriminating between high- and low-risk disease, creating a need for a reliable marker to determine aggressiveness. Prostate-specific membrane antigen (PSMA) appears to fulfill this need. We analyzed 79 prostate biopsies and 28 prostatectomies to assess whether PSMA expression detected by immunohistochemistry is related to GS. PSMA expression was correlated with GS in both sample types (biopsies, P vs. Gleason pattern 4 and 5, PSMA sensitivity was 84.1% (95% CI 76.5%-91.7%) and specificity was 95.2% (95% CI 90.6%-99.8%), with an area under the curve of 93.1 (95% CI 88.8–97.4). Our results suggest that PSMA represents a potential ally for the pathologist in the diagnostic work-up of PCa to overcome long-standing morphological classification limits.

Circulating tumor cells (CTCs) are associated with poor survival in metastatic cancer. Their identification, phenotyping, and genotyping could lead to a better understanding of tumor heterogeneity and thus facilitate the selection of patients for personalized treatment. However, this is hampered because of the rarity of CTCs. We present an innovative approach for sampling a high volume of the patient blood and obtaining information about presence, phenotype, and gene translocation of CTCs. The method combines immunofluorescence staining and DNA fluorescent-in-situ-hybridization (DNA FISH) and is based on a functionalized medical wire. This wire is an innovative device that permits the in vivo isolation of CTCs from a large volume of peripheral blood. The blood volume screened by a 30-min administration of the wire is approximately 1.5-3 L. To demonstrate the feasibility of this approach, epithelial cell adhesion molecule (EpCAM) expression and the chromosomal translocation of the ALK gene were determined in non-small-cell lung cancer (NSCLC) cell lines captured by the functionalized wire and stained with an immuno-DNA FISH approach. Our main challenge was to perform the assay on a 3D structure, the functionalized wire, and to determine immuno-phenotype and FISH signals on this support using a conventional fluorescence microscope. The results obtained indicate that catching CTCs and analyzing their phenotype and chromosomal rearrangement could potentially represent a new companion diagnostic approach and provide an innovative strategy for improving personalized cancer treatments.

In order to examine potential differences in genomic stability, we have challenged fibroblasts derived from five different mammalian species of variable longevity with the genotoxic agents, etoposide and neocarzinostatin. We report that cells from longer-lived species exhibit more tumor protein p53 binding protein 1 (53BP1) foci for a given degree of DNA damage relative to shorter-lived species. The presence of a greater number of 53BP1 foci was associated with decreased DNA fragmentation and a lower percentage of cells exhibiting micronuclei. These data suggest that cells from longer-lived species have an enhanced DNA damage response. We propose that the number of 53BP1 foci that form in response to damage reflects the intrinsic capacity of cells to detect and respond to DNA harms.

Background - Circulating tumor cells (CTCs) are the liquid phase of a solid tumor. An advanced CTC phenotyping and genotyping procedure could allow a superior understanding of tumor heterogeneity aimed at improving personalized treatment selection. However, these investigations are hampered by the difficulty to catch and analyze CTCs. EML4-ALK chromosomal rearrangement is a fundamental marker of sensitivity in metastatic non-small cell lung cancer (mNSCLC), but conventional tissue-based ALK scrutiny is not always possible. A CTC-based ALK evaluation may be an easy and not invasive method for identifying rearrangements and hence patients eligible for specific treatments. Methods - Analyses were performed via the Gilupi CellCollector CANCER01 (DC01), a device that allows the in vivo isolation of CTCs from a high volume of peripheral blood. The DC01 is a CE-approved functionalized 16 cm long medical wire that includes a functionalized 2 cm long gold-coated tip covalently coupled with antibodies against EpCAM. The DC01 can be inserted through a standard venous cannula into the cubital vein of cancer patients for 30 minutes where it captures CTCs directly from the bloodstream of cancer patients. CTC presence was investigated in 18 mNSCLC patients and CTC-ALK-chromosomal status was studied by an innovative method, the 3D-immuno-FISH, that combined immuno-fluorescence and FISH approaches on a 3D structure (the DC01). Two DC01 per patients were utilized. After removal, on one wire, CTCs were identified and counted by nuclei, EpCAM and cytokeratins staining. On the second wire, CTCs were recognized by EpCAM staining and analyzed for ALK alterations by FISH. Formalin-fixed paraffin-embedded primary tumor tissues from the same patients were analyzed for comparison. Immortalized cell lines attached to DC01 devices were exploited as positive controls. Results - Using the DC01 it was feasible to isolate and detect CTCs. Among the 18 enrolled patients, 7 presented tumor-tissue ALK-translocation, whereas 11 were wild type. Overall, 61.1% patients were CTC positive (median CTC number, 3.0 per patient). Amid those that owned ALK-translocation, 28.6% were CTC-positive, whereas 81.8 % patient without ALK-translocation were CTC positive. ALK rearrangements were detectable directly on cells attached to the wires. However, the 3D-immuno-FISH analysis in patients was hampered by the low median number of detected CTCs. Conclusions - The detection of ALK-chromosomal rearrangements with the 3D-immuno-FISH analysis in cells recovered by DC01 was feasible. This method is valid for tracking positive CTC patients, but the few cells retrieved per patients still limit CTC full exploitation. Although further studies are needed to validate our data and to improve DC01 capture efficiency, our results pave the way to CTC-based chromosomal rearrangement identification and therapy personalization. Citation Format: Giulia Gallerani, Angelo Delmonte, Claudia Cocchi, Martine Bocchini, Filippo Piccinini, Marco Angelo Burgio, Carla Casadei, Andrea Rocca, Francesco Fabbri. Feasibility investigation of EML4-ALK rearrangements in mNSCLC CTCs using a new in vivo procedure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5196.