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Small cell lung cancer (SCLC) is an aggressive tumor, and despite its sensitivity to chemotherapy and radiotherapy, patients usually have a short survival. There are no clinically relevant predictive factors of responses to therapies, and therapeutic options are still limited.Clinical data and somatic mutations of genes included in the MSK-IMPACT panel were retrieved from cBioPortal for 108 SCLCs and analyzed to identify mutated gene networks. Results were validated in an independent cohort of 54 SCLCs, whose information was also available from cBioPortal.Different networks were observed in tumors of short and long survivors. Degree (K) and betweenness (B) are key features that characterize a gene in its network of related mutations. By comparing their B/K ratio, 2 signatures of mutated genes were identified, describing short (IL-7R, NTRK2, HNF-1A) and long survivors (NBN, PTPN-11, IRS-1, INPP-4A, PIK-3CG, HGF, LATS-2, SMARCA-4, FLT-3, EIF-4A2, SPEN, PAX-5, SH2-D1A, ARID-1A, HOXB-13, ERCC-4, FANCA, FH, FGFR-2, MST-1R, SMAD-4, DDR-2, IGF-1R, PIK-3CB). Patients with at least 1 mutated gene of the short signature had a worse median overall survival of 8 versus 28 months (P.001). Patients with at least 1 mutated gene of the long signature had a better median overall survival of 39 versus 20 months (P = .004). The value of the short signature was further confirmed in an independent cohort of SCLCs.The networks of mutated genes could help subclassify SCLCs based on their somatic mutations and aid in identifying a subset of tumors with poor prognosis.

Purposes: To determine whether the deregulation of genes relevant for normal thymus development can contribute to the biology of thymic epithelial tumors (TET).Experimental Design: Using array comparative genomic hybridization, we evaluated the copy number aberrations of genes regulating thymus development. The expression of genes most commonly involved in copy number aberrations was evaluated by immunohistochemistry and correlated with patients' outcome. Correlation between FOXC1 copy number loss and gene expression was determined in a confirmation cohort. Cell lines were used to test the role of FOXC1 in tumors.Results: Among 31 thymus development-related genes, PBX1 copy number gain and FOXC1 copy number loss were presented in 43.0% and 39.5% of the tumors, respectively. Immunohistochemistry on a series of 132 TETs, including those evaluated by comparative genomic hybridization, revealed a correlation between protein expression and copy number status only for FOXC1 but not for PBX1. Patients with FOXC1-negative tumors had a shorter time to progression and a trend for a shorter disease-related survival. The correlation between FOXC1 copy number loss and mRNA expression was confirmed in a separate cohort of 27 TETs. Ectopic FOXC1 expression attenuated anchorage-independent cell growth and cell migration in vitro.Conclusion: Our data support a tumor suppressor role of FOXC1 in TETs. Clin Cancer Res; 19(8); 1960–71. ©2013 AACR.

Purposes: Pancreatic cancer is the fourth leading cause of cancer-related death, and studies on the clinical relevance of its genomic imbalances are warranted.Experimental Design: Recurrent copy number alterations of cytobands and genes were analyzed by array comparative genomic hybridization (aCGH) in 44 resected pancreatic cancer specimens. Prognostic markers identified by aCGH were validated by PCR gene copy number assay in an independent validation cohort of 61 resected pancreatic cancers. The functions of gene identified were evaluated by proliferation, cell cycle, and migration assays in pancreatic cancer cells.Results: We showed recurrent copy number gains and losses in the first cohort. Loss of 18q22.3 was significantly associated with short-term overall survival in the first cohort (P = 0.019). This cytoband includes the carboxypeptidase of glutamate-like (CPGL) gene. CPGL gene deletion was associated with shorter overall survival in the validation cohort (P = 0.003). CPGL deletion and mutations of TP53 or Kras seem to be independent events. A Cox model analysis of the two cohorts combined showed that loss of 18q22.3/deletion of the CPGL gene was an independent poor prognostic factor for overall survival (HR = 2.72, P = 0.0007). Reconstitution of CPGL or its splicing variant CPGL-B into CPGL-negative pancreatic cancer cells attenuated cell growth, migration, and induced G1 accumulation.Conclusion: Loss of 18q22.3/deletion of the CPGL gene is a poor prognostic marker in resected pancreatic cancer, and functional studies suggest the CPGL gene as growth suppressor gene in pancreatic cancer. Clin Cancer Res; 18(2); 524–33. ©2011 AACR.

PDF file - 3704K, Copy number aberrations of genes regulating normal thymus development in the confirmation cohort.

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PDF file - 2727K, Frequency of FOXC1 copy number loss and PBX1 copy number gain in the WHO histotypes overall in the 2 cohorts.

PDF file - 3599K, Copy number aberrations of genes regulating normal thymus development overall in the 2 cohorts.

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This study determined whether expression levels of a panel of biologically relevant microRNAs can be used as prognostic or predictive biomarkers in patients who participated in the International Adjuvant Lung Cancer Trial (IALT), the largest randomized study conducted to date of adjuvant chemotherapy in patients with radically resected non–small cell lung carcinoma (NSCLC). Expression of miR-21, miR-29b, miR-34a/b/c, miR-155, and let-7a was determined by quantitative real-time PCR in formalin-fixed paraffin-embedded tumor specimens from 639 IALT patients. The prognostic and predictive values of microRNA expression for survival were studied using a Cox model, which included every factor used in the stratified randomization, clinicopathologic prognostic factors, and other factors statistically related to microRNA expression. Investigation of the expression pattern of microRNAs in situ was performed. We also analyzed the association of TP53 mutation status and miR-34a/b/c expression, epidermal growth factor receptor and KRAS mutation status, and miR-21 and Let-7a expression. Finally, the association of p16 and miR-29b expression was assessed. Overall, no significant association was found between any of the tested microRNAs and survival, with the exception of miR-21 for which a deleterious prognostic effect of lowered expression was suggested. Otherwise, no single or combinatorial microRNA expression profile predicted response to adjuvant cisplatin-based chemotherapy. Together, our results indicate that the microRNA expression patterns examined were neither predictive nor prognostic in a large patient cohort with radically resected NSCLC, randomized to receive adjuvant cisplatin-based chemotherapy versus follow-up only. Cancer Res; 70(21); 8288–98. ©2010 AACR.

Supplementary Appendix 1 from MicroRNA Expression and Clinical Outcomes in Patients Treated with Adjuvant Chemotherapy after Complete Resection of Non–Small Cell Lung Carcinoma

Supplementary Figure 1 from MicroRNA Expression and Clinical Outcomes in Patients Treated with Adjuvant Chemotherapy after Complete Resection of Non–Small Cell Lung Carcinoma

Supplementary Tables 1-9 from MicroRNA Expression and Clinical Outcomes in Patients Treated with Adjuvant Chemotherapy after Complete Resection of Non–Small Cell Lung Carcinoma

BACKGROUND: Thymomas can benefit of cytoreductive surgery even if a complete resection is not feasible. The pleural cavity is the most common site of progression and the resection of pleural metastases can be performed in selected patients. We evaluated the results of stereotactic body radiation therapy for the treatment of pleural metastases in patients not eligible for surgery. METHODS: We retrospectively selected 22 patients treated with stereotactic body radiation therapy for pleural metastases between 2013 and 2019. According to RECIST criteria 1.1 modified for thymic epithelial tumors, time to local failure and progression free survival were calculated using Kaplan-Meier method. RESULTS: The median age was 40 years (range, 29–73 years). There were 1 A, 3 AB, 3 B1, 3 B2, 3 B2/B3 and 9 B3 thymomas. Pleural metastases and primary tumor were synchronous in 8 patients. Five patients had a single pleural metastatic site and 17 presented multiple localizations. Sixteen patients received stereotactic body radiation therapy on multiple sites of pleural metastases. The median dose of radiation was 30 Gy (range, 24–40 Gy). With a median follow-up of 33.2 months (95% CI: 13.1–53.3 months), ten patients experienced disease progression with a median progression free survival was 20.4 months (95% CI: 10.7–30.0 months). The disease control rate was 79% and 41% after 1 and 2 years, respectively. Local disease control rate was 92% and 78% after 1 and 2 years, respectively. There were not significant differences in progression free survival between patients diagnosed with synchronous and metachronous metastases (P=0.477), across those treated or not with chemotherapy (P=0.189) and between those who received or not a previous surgical resection of the pleural metastases (P=0.871). There were not grade 3–4 toxicities related to the treatment. CONCLUSIONS: Stereotactic body radiation therapy of pleural metastases is feasible and offers a promising local control of diseases. The impact of this treatment on patients’ survival is hardly predictable because of the heterogeneous clinical behavior of thymomas.

Programmed death ligand 1 (PD-L1) plays a key role in several human tumors, and it has recently become a crucial target for cancer therapy. Yet, its subtle regulatory roles beside the well characterized immunosuppression in PD-1/PD-L1 immune checkpoint are still obscure and should be strictly related to its molecular properties in different cell settings. In this study we targeted the plasma membrane organization of PD-L1 in a Non-Small Cell Lung Cancer (NSCLC) cell line by a multiscale fluorescence imaging toolbox that included super-resolution microscopy approaches to reach the nanoscale. Our findings revealed for the first time that PD-L1 is prevalently engaged in the cholesterol-enriched “raft” regions of the cell membrane. Clusterization and engagement in membrane rafts may afford novel targets for the immuno-oncology strategies in the framework of NSCLC and, possibly, other tumor types.

Simple Summary The extra-domain B fibronectin (ED-B FN) is highly expressed in thymic epithelial tumors (TETs), as demonstrated by in vivo targeting using 131I-labeled L19 small immunoprotein (131I-L19-SIP) and immunohistochemistry with a predominant expression by stromal cells of a thymoma microenvironment rather than epithelial cells. Such high expression derived from the induction of stromal cells shifts FN production to the ED-B subtype. Our results suggest that Radretumab radioimmunotherapy (R-RIT) inefficacy is not related to low TET ED-B expression but to multifactorial aspects including patients' inherent characteristics, the pattern expression of the target, the biological characteristics of the tumor, and the format of the target agent, which contribute to the resistance of tumor cells to treatment. Aim: to exploit tissue-specific interactions among thymic epithelial tumor (TETs) cells and extra-domain B fibronectin (ED-B FN). Material and methods: The stromal pattern of ED-B FN expression was investigated through tumor specimen collection and molecular profiling in 11 patients with recurrent TETs enrolled in prospective theragnostic phase I/II trials with Radretumab, an ED-B FN specific recombinant human antibody. Radretumab radioimmunotherapy (R-RIT) was offered to patients who exhibited the target expression. Experiments included immunochemical analysis (ICH), cell cultures, immunophenotypic analysis, Western blot, slot-blot assay, and quantitative RT-PCR of two primary thymoma cultures we obtained from patients' samples and in the Ty82 cell line. Results: The in vivo scintigraphic demonstration of ED-B FN expression resulted in R-RIT eligibility in 8/11 patients, of which seven were treated. The best observed response was disease stabilization (n = 5/7) with a duration of 4.3 months (range 3-5 months). IHC data confirmed high ED-B FN expression in the peripherical microenvironment rather than in the center of the tumor, which was more abundant in B3 thymomas. Further, there was a predominant expression of ED-B FN by the stromal cells of the thymoma microenvironment rather than the epithelial cells. Conclusions: Our data support the hypothesis that thymomas induce stromal cells to shift FN production to the ED-B subtype, likely representing a favorable hallmark for tumor progression and metastasis. Collectively, results derived from clinical experience and molecular insights of the in vitro experiments suggested that R-RIT inefficacy is unlikely related to low target expression in TET, being the mechanism of R-RIT resistance eventually related to patients' susceptibility (i.e., inherent characteristics), the pattern expression of the target (i.e., at periphery), the biological characteristics of the tumor (i.e., aggressive and resistant phenotypes), and/or to format of the target agent (i.e., 131I-L19-SIP).

Background Insights into the mechanism of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) could provide important information for further patient management, including the choice of second-line treatment. The EGFR T790M mutation is the most common mechanism of resistance to first- and second-generation EGFR TKIs. Owing to its biologic relevance in the response of non–small-cell lung cancer (NSCLC) to the selective pressure of treatment, the present study investigated whether the occurrence of T790M at progression differed among patients receiving gefitinib, erlotinib, or afatinib. Patients and Methods The present retrospective study included patients with NSCLC with an EGFR activating mutation, who had received gefitinib, erlotinib, or afatinib as first-line treatment. Plasma samples for the analysis of cell-free DNA were taken at disease progression and analyzed using a digital droplet polymerase chain reaction EGFR mutation assay. Results A total of 83 patients were enrolled; 42 had received gefitinib or erlotinib and 41afatinib. The patient characteristics were comparable across the 2 groups. The median time to progression (TTP) was 14.4 months for the gefitinib and erlotinib group and 10.2 months for the afatinib group (P = .09). Of the 83 patients, 47 (56.6%) were positive for the T790M in plasma. A greater incidence of T790M was observed in patients with progression during gefitinib or erlotinib therapy compared with patients treated with afatinib (33 [79%] vs. 14 [34%], respectively; odds ratio, 7.1; 95% confidence interval, 2.7-18.5; P = .0001). Conclusions Although gefitinib, erlotinib, and afatinib showed a comparable TTP in patients receiving first-line therapy, the incidence of T790M differed among them, as demonstrated by the present study, which could have implications for the choice of second-line treatment.

DNA methylation (5mC) is a promising biomarker for detecting circulating tumor DNA (ctDNA), providing information on a cell9s genomic regulation, developmental lineage, and molecular age. Sequencing assays for detecting ctDNA methylation involve pre-processing steps such as immunoprecipitation, enzymatic treatment, or the most common method, sodium bisulfite treatment. These steps add complexity and time that pose a challenge for clinical labs, and bisulfite treatment in particular degrades input DNA and can result in loss of informative ctDNA fragmentation patterns. In this feasibility study, we demonstrate that whole genome sequencing of circulating cell-free DNA using conventional Oxford Nanopore Technologies (ONT) sequencing can accurately detect cell-of-origin and cancer-specific 5mC changes while preserving important fragmentomic information. The simplicity of this approach makes it attractive as a liquid biopsy assay for cancer as well as non-cancer applications in emergency medicine.

Lung cancer has become a paradigm for precision medicine in oncology, and liquid biopsy (LB) together with radiomics may have a great potential in this scenario. They are both minimally invasive, easy to perform, and can be repeated during patient’s follow-up. Also, increasing evidence suggest that LB and radiomics may provide an efficient way to screen and diagnose tumors at an early stage, including the monitoring of any change in the tumor molecular profile. This could allow treatment optimization, improvement of patients' quality of life, and healthcare-related costs reduction. Latest reports on lung cancer patients suggest a combination of these two strategies, along with cutting-edge data analysis, to decode valuable information regarding tumor type, aggressiveness, progression, and response to treatment. The approach seems more compatible with clinical practice than the current standard, and provides new diagnostic companions being able to suggest the best treatment strategy compared to conventional methods. To implement radiomics and liquid biopsy directly into clinical practice, an artificial intelligence (AI)-based system could help to link patients' clinical data together with tumor molecular profiles and imaging characteristics. AI could also solve problems and limitations related to LB and radiomics methodologies. Further work is needed, including new health policies and the access to large amounts of high-quality and well-organized data, allowing a complementary and synergistic combination of LB and imaging, to provide an attractive choice e in the personalized treatment of lung cancer.

BackgroundMaintenance treatment after autologous bone marrow transplantation in multiple myeloma improves the outcome of patients. We designed a phase II clinical trial to evaluate the treatment with IL2 and zoledronate after autologous bone marrow transplantation in myeloma patients.MethodsPatients with a histologically proven diagnosis of multiple myeloma become eligible if achieved a very good partial remission in bone marrow samples after 3 months from autologous bone marrow transplantation. IL2 was administered from day 1 to 7. In the first cycle, the daily dose was 2 × 106 IU, whereas, in subsequent ones the IL2 dose was progressively escalated, with +25% increases at each cycle, until evidence of toxicity or up to 8 × 106 IU. Four mg of zoledronic acid were infused on day 2. Flow cytometry analysis of γδ-lymphocytes was performed at days 1 and 8 of treatment cycles.ResultsForty-four patients have been enrolled between 2013 and 2016. The median time to progression was 22.5 months (95% CI 9.7–35.2). A complete remission with a negative immunofixation was obtained in 18% of patients and correlated with a significantly longer time to progression (p = 0.015). Treatment was well tolerated without G3 or 4 toxicities. After a week of treatment with IL2 and zoledronate, γδ lymphocytes, Vγ9δ2, CD57+, effector, late effector, and memory γδ increased but in subsequent cycles, there was a progressive reduction of this expansion.ConclusionsThe maintenance treatment with IL2 and Zoledronate has a modest activity in myeloma patients after autologous bone marrow transplantation.EudraCT Number2013-001188-22.

Resistance to EGFR tyrosin kinase inhibitors (TKI) inevitably occurs. Here it is reported the case of a young patient affected by lung adenocarcinoma harboring the L858R EGFR sensitive mutation. The patient developed multiple TKI resistance mechanisms: T790M EGFR resistance mutation, detected only on tumor cell-free DNA, squamous cell transformation and MET amplification, both detected on a tumor re-biopsy. The co-occurrence of squamous cell transformation and de novo MET amplification is an extremely rare event, and this case confirms how dynamic and heterogeneous can be the temporal and spatial tumor evolution under treatment pressure.

OBJECTIVE: With this narrative review, we retraced the history of hypertermic intrathoracic chemotherapy (HITHOC) since the beginning, analyzing literature on operative technique, feasibility and efficacy of this treatment. Moreover, we report the fifteen-year experience of our center in this relatively new technique, for what concerns both early postoperative results and long-term oncological outcomes. BACKGROUND: Thymomas are frequently misdiagnosed and recognized in advanced stage, often with pleural dissemination, especially when not associated to Myasthenia Gravis that allows an early diagnosis during the initial assessment. Moreover, the natural history of locally advanced thymoma is characterized by a high rate of pleural or pericardial relapses. Surgery has always been considered a milestone in thymoma’s treatment, even in case of serous dissemination or relapses, although his role as exclusive therapy does not guarantee an acceptable local disease control. In case of disseminated disease, different multidisciplinary protocols have been experimented, from chemotherapy to radiation therapy, alone or associated to surgery, in order to increase overall and disease-free survival, but the breakthrough happened in the early 90s with the introduction of HITHOC following surgery. Combination of surgery and HITHOC resulted in less toxic than systemic chemotherapy and providing a good local disease control in patients with stage IVa thymomas or thymoma’s pleural recurrences. METHODS: We searched PubMed for relevant literature, up to January 2020, on hypertermic intrapleural chemotherapy for thymomas (TPR or DNT), selecting only those reporting information about HITHOC protocol used, postoperative course and oncological outcomes. CONCLUSIONS: HITHOC is a safe and feasible procedure, with a very low complication rate and negligible systemic effects of chemotherapeutic agents, effective in controlling both TPR and DNT, in particular as regards local disease-free survival. KEYWORDS: Hypertermic intrathoracic chemotherapy (HITHOC); thymoma; intracavitary chemotherapy; hyperthermia; redo-surgery

In the “precision oncology” era the characterization of tumor genetic features is a pivotal step in cancer patients’ management. Liquid biopsy approaches, such as analysis of cell-free DNA from plasma, represent a powerful and noninvasive strategy to obtain information about the genomic status of the tumor. Sequencing-based analyses of cell-free DNA, currently performed with second generation sequencers, are extremely powerful but poorly scalable and not always accessible also due to instrumentation costs. Third generation sequencing platforms, such as Nanopore sequencers, aim at overcoming these obstacles but, unfortunately, are not designed for cell-free DNA analysis. Here we present a customized workflow to exploit low-coverage Nanopore sequencing for the detection of copy number variations from plasma of cancer patients. Whole genome molecular karyotypes of 6 lung cancer patients and 4 healthy subjects were successfully produced with as few as 2 million reads, and common lung-related copy number alterations were readily detected. This is the first successful use of Nanopore sequencing for copy number profiling from plasma DNA. In this context, Nanopore represents a reliable alternative to Illumina sequencing, with the advantages of minute instrumentation costs and extremely short analysis time. The availability of protocols for Nanopore-based cell-free DNA analysis will make this analysis finally accessible, exploiting the full potential of liquid biopsy both for research and clinical purposes. Supplementary Information The online version contains supplementary material available at 10.1186/s12943-021-01327-5.

The Italian Association of Medical Oncology recommendations on thymic epithelial tumors, which have been drawn up for the first time in 2020 through an evidence-based approach, report indications on all the main aspects of clinical management of this group of rare diseases, from diagnosis and staging, to new available systemic treatments, such as targeted therapies and immunotherapies. A summary of key recommendations is presented here and complete recommendations are reported as Supplementary Materials, available at https://doi.org/10.1016/j.esmoop.2021.100188., Highlights • Thymic epithelial tumors (TETs). • Multidisciplinary management of patients with TETs. • Rare cancers. • Updated recommendations.

Alterations in the genetic content, such as Copy Number Variations (CNVs) is one of the hallmarks of cancer and their detection is used to recognize tumoral DNA. Analysis of cell-free DNA from plasma is a powerful tool for non-invasive disease monitoring in cancer patients. Here we exploit third generation sequencing (Nanopore) to obtain a CNVs profile of tumoral DNA from plasma, where cancer-related chromosomal alterations are readily identifiable.Compared to Illumina sequencing -the only available alternative- Nanopore sequencing represents a viable approach to characterize the molecular phenotype, both for its ease of use, costs and rapid turnaround (6 hours).

A number of treatments have been developed for HER1, 2 and 3-driven non-small cell lung cancer (NSCLC), of which the most successful have been the epidermal growth factor receptor-tyrosine kinase inhibitors in HER1-mutant tumours resulting in highly improved progression-free survival. Human epidermal growth factor (HER)2 and 3-driven tumours represent the minority of NSCLC, and effective therapies in these patients still represent an unmet medical need. The encouraging results seen with anti-HER2 and anti-HER3 monoclonal antibodies need to be validated in larger studies, even if the greatest obstacle is represented by the exiguous number of patients bearing deregulated HER2/3 system and abnormalities of signal transduction pathway. Considering NSCLC tumour heterogeneity, which affects response and resistance to treatment, combined multiparametric approaches, such as liquid biopsy together with radiomics, may provide a better understanding of the tumour dynamics and clonal selection during the treatments.

Background It is still unclear how to combine biomarkers to identify patients who will truly benefit from anti-PD-1 agents in NSCLC. This study investigates exosomal mRNA expression of PD-L1 and IFN-γ, PD-L1 polymorphisms, tumor mutational load (TML) in circulating cell-free DNA (cfDNA) and radiomic features as possible predictive markers of response to nivolumab and pembrolizumab in metastatic NSCLC patients. Methods Patients were enrolled and blood (12 ml) was collected at baseline before receiving anti-PD-1 therapy. Exosome-derived mRNA and cfDNA were extracted to analyse PD-L1 and IFN-γ expression and tumor mutational load (TML) by digital droplet PCR (ddPCR) and next-generation sequencing (NGS), respectively. The PD-L1 single nucleotide polymorphisms (SNPs) c.-14-368 T > C and c.*395G > C, were analysed on genomic DNA by Real-Time PCR. A radiomic analysis was performed on the QUIBIM Precision® V3.0 platform. Results Thirty-eight patients were enrolled. High baseline IFN-γ was independently associated with shorter median PFS (5.6 months vs. not reached p = 0.0057), and levels of PD-L1 showed an increase at 3 months vs. baseline in patients who progressed (p = 0.01). PD-L1 baseline levels showed significant direct and inverse relationships with radiomic features. Radiomic features also inversely correlated with PD-L1 expression in tumor tissue. In subjects receiving nivolumab, median PFS was shorter in carriers of c.*395GG vs. c.*395GC/CC genotype (2.3 months vs. not reached, p = 0.041). Lastly, responders had higher non-synonymous mutations and more links between co-occurring genetic somatic mutations and ARID1A alterations as well. Conclusions A combined multiparametric approach may provide a better understanding of the molecular determinants of response to immunotherapy.

Background Thymoma and myasthenia gravis share several pathogenetic aspects including the role of surgery as a therapeutic option. Extended thymectomy is associated with excellent survival and good local control, especially in early stages, and its role for the neurologic disease has been recently validated. The aim of this study is evaluating oncologic and neurologic outcomes of myasthenic patients with thymoma who underwent extended thymectomy. Methods We retrospectively collected surgical, oncologic, and neurologic data of all myasthenic patients with thymoma who underwent extended thymectomy at our department from January 1994 to December 2016. Clinical and pathologic data, neurologic remission rate, and overall survival and disease-free interval were analyzed. Results In all, 219 patients underwent extended thymectomy. The B2 histotype was the most represented thymoma (24.2%), and the most prevalent pathologic Masaoka stage was IIB (37.9%). The overall survival and disease-free survival were statistically different between early stage and advanced stage. During the surveillance, 33 patients (15.1%) had recurrences, treated in 21 cases with iterative surgery. Regarding neurologic outcomes, 75 patients (34.2%) reached a complete stable remission, 84 (38.4%) a pharmacologic remission, 51 (23.3%) had an improvement of their symptoms, and in 9 patients (4.1%) myasthenia was unchanged or worsened. Conclusions Surgery is a cornerstone in the treatment of patients with both thymoma and myasthenia gravis. Extended thymectomy, as proposed by Masaoka, offers considerable oncologic outcomes with an excellent survival and low recurrence rate of thymoma; moreover, surgery leads to remarkable neurologic results.

Molecular heterogeneity characterizes tumours’ evolution and adaptation and, because of its dynamics and continuous changes under external pressure, it is one of the major causes of drug resistance, contributing to therapy failure. Several studies reported evidence of molecular events occuring in individual tumours, including monoclonal or polyclonal resistance, and primary or secondary resistance mechanisms. While primary resistance is a phenomenon already present at the diagnosis of a tumor, the acquired one is strongly related to the selective pressure of treatments administered. Therefore, the pharmacological characteristics of a drug, including its potency, binding affinity and structure, largely influence the mechanism of resistance that will arise at the progression of the disease. As an example, the lung cancer experience clearly demonstrated that the highest is the potency of a drug on its target, the more are the possibilities that the mechanism of resistance will arise independently of the target itself. The present review is focused on tumour heterogeneity and its relation to resistance to targeted-therapy, based on treatment selective pressure across different tumour types, including lung, colorectal, prostate, breast cancer and melanoma. The mechanisms of resistance based on the drug potency and the selective pressure of treatments are discussed, leading to new drug developments or new therapeutic combinations.

Background Circulating cell-free DNA (cfDNA) may help understand the molecular response to pharmacologic treatment and provide information on dynamics of clonal heterogeneity. Therefore, this study evaluated the correlation between treatment outcome and activating EGFR mutations (act-EGFR) and T790M in cfDNA in patients with advanced NSCLC given osimertinib. Methods Thirty-four NSCLC patients resistant to first/second-generation EGFR-TKIs, positive for both act-EGFR and T790M in cfDNA at the time of progression were enrolled in this study. Plasma samples were obtained at osimertinib baseline and after 3 months of therapy; cfDNA was analyzed by droplet digital PCR and results were expressed as mutant allele frequency (MAF). Results At baseline, act-EGFR MAF was significantly higher than T790M (p 2.6% and 0.22 (6 months vs. not reached, respectively, p = 0.01). Conclusion act-EGFR MAF and T790M/act-EGFR MAF ratio are potential markers of outcome in patients treated with osimertinib.