Reconstruction of Complex Anterior Chest Wall Defects: The Lasagna Technique.

Background: Sternal tumors are rare, comprising only 0.94% of all bone tumors, with the majority being sarcomas. An extensive composite defect is often the result of surgical resection. Reconstruction of this anatomical area is a challenge for plastic surgeons. Reconstruction must fulfil two different tasks: restoration of soft tissues and stabilization of the chest wall. Both are well defined, and many techniques have been historically proposed. Methods: We present the case of a 66-year-old man affected by sternal metastasis of lung non-small cell carcinoma with sarcomatoid features. After wide tumor resection, a large defect was created. Results: The patient underwent a complex multilayer reconstruction that combined multiple techniques: Gore DualMesh to reconstruct the pericardial plane and protect the heart muscle, omental flap to facilitate integration of the mesh, titanium bars to recreate chest wall stability, and bilateral pectoralis muscle flaps to cover hardware. This multilayer reconstruction was named the "lasagna technique." Conclusions: Due to the rarity of primary malignancies of the sternum, it is difficult to standardize a therapeutic approach. For this reason, it is necessary to customize the surgical treatment by combining several techniques and materials. Our lasagna technique may be considered a valuable option in treating these complex reconstructive cases.

Oncosuppressive miRNAs loaded in lipid nanoparticles potentiate targeted therapies in BRAF-mutant melanoma by inhibiting core escape pathways of resistance.

BRAF-mutated melanoma relapsing after targeted therapies is an aggressive disease with unmet clinical need. Hence the need to identify novel combination therapies able to overcome drug resistance. miRNAs have emerged as orchestrators of non-genetic mechanisms adopted by melanoma cells to challenge therapies. In this context we previously identified a subset of oncosuppressor miRNAs downregulated in drug-resistant melanomas. Here we demonstrate that lipid nanoparticles co-encapsulating two of them, miR-199-5p and miR-204-5p, inhibit tumor growth both in vitro and in vivo in combination with target therapy and block the development of drug resistance. Mechanistically they act by directly reducing melanoma cell growth and also indirectly by hampering the recruitment and reprogramming of pro-tumoral macrophages. Molecularly, we demonstrate that the effects on macrophages are mediated by the dysregulation of a newly identified miR-204-5p-miR-199b-5p/CCL5 axis. Finally, we unveiled that M2 macrophages programs are molecular signatures of resistance and predict response to therapy in patients. Overall, these findings have strong translational implications to propose new combination therapies making use of RNA therapeutics for metastatic melanoma patients.

Identification of a miRNA-based non-invasive predictive biomarker of response to target therapy in BRAF-mutant melanoma.

Rationale: Metastatic melanoma is the most aggressive and dangerous form of skin cancer. The introduction of immunotherapy with Immune checkpoint Inhibitors (ICI) and of targeted therapy with BRAF and MEK inhibitors for BRAF mutated melanoma, has greatly improved the clinical outcome of these patients. Nevertheless, response to therapy remains highly variable and the development of drug resistance continues to be a daunting challenge. Within this context there is a need to develop diagnostic tools capable of predicting response or resistance to therapy in order to select the best therapeutic approach. Over the years, accumulating evidence brought to light the role of microRNAs (miRNAs) as disease biomarkers. Methods: In particular, the detection of miRNAs in whole blood or specific blood components such as serum or plasma, allows these molecules to be good candidates for diagnosis, prognosis and for monitoring response to anticancer therapy. In this paper, we evaluated circulating basal levels of 6 previously identified miRNAs in serum samples of 70 BRAF-mutant melanoma patients before starting targeted therapy. Results: Results show that the circulating levels of the oncosuppressor miR-579-3p and of the oncomiR miR-4488 are able to predict progression free survival (PFS) but not overall survival (OS). Most importantly, we observed that the best predictor of disease outcome is represented by the ratio of circulating miR-4488 vs. miR-579-3p (miRatio). Finally, the combination of the Lactate dehydrogenase (LDH) blood levels with the two circulating miRNAs alone or together did not produce any improvement in predicting PFS indicating that miR-579-3p and miR-4488 are independent predictors of PFS as compared to LDH. Conclusions: All together these data underscored the relevance of circulating miRNAs as suitable tools to predict therapy response in melanoma and maybe further developed as companion diagnostics in the clinic.

The Promise of Liquid Biopsy to Predict Response to Immunotherapy in Metastatic Melanoma.

Metastatic melanoma is the deadliest form of skin cancer whose incidence has been rising dramatically over the last few decades. Nowadays, the most successful approach in treating advanced melanoma is immunotherapy which encompasses the use of immune checkpoint blockers able to unleash the immune system's activity against tumor cells. Immunotherapy has dramatically changed clinical practice by contributing to increasing long term overall survival. Despite these striking therapeutic effects, the clinical benefits are strongly mitigated by innate or acquired resistance. In this context, it is of utmost importance to develop methods capable of predicting patient response to immunotherapy. To this purpose, one major step forward may be provided by measuring non-invasive biomarkers in human fluids, namely Liquid Biopsies (LBs). Several LB approaches have been developed over the last few years thanks to technological breakthroughs that have allowed to evaluate circulating components also when they are present in low abundance. The elements of this so-called "circulome" mostly encompass: tumor DNA, tumor and immune cells, soluble factors and non-coding RNAs. Here, we review the current knowledge of these molecules as predictors of response to immunotherapy in metastatic melanoma and predict that LB will soon enter into routine practice in order to guide clinical decisions for cancer immunotherapy.

Use of Octreotide in association with talc poudrage for the management of a severe chylothorax: A case report.

INTRODUCTION AND IMPORTANCE: Chylothorax is an uncommon form of pleural effusion characterized by the presence of chylomicrons, triglycerides and cholesterol in the physical and chemical examination of the pleural fluid. It may have poor prognosis if not properly treated. Currently, conservative measures are the first line of treatment for managing chylothorax. The aim of our study is to show and suggest the use of octreotide in association with talc poudrage as good option to manage post-operative a severe chylothorax. CASE PRESENTATION: A 59-year-old male patient who underwent a replacement of the ascending aorta, aortic hemiarch and surgery of the aortic valve for aortic dissection showed a severe pleural effusion three months after surgery. Because the physical and chemical examination of the pleural fluid revealed high levels of triglycerides and cholesterol, a conservative treatment with pleural drainage, TPN and nihil per os was attempted, with the introduction of 0.3 mg/die of octreotide on day thirty-four. With the application of talc poudrage, the chylothorax completely resolved. CLINICAL DISCUSSION: Octreotide has been shown to significantly decrease chylous effusion in many studies, but the dose and duration of therapy have not yet been defined. Our patient responded partially to octreotide after two days of treatment, with the drainage leak reduced to less than 100 mL/day. CONCLUSION: After octreotide treatment associated with talc poudrage, the drainage leak was drastically reduced, suggesting that this could be a useful approach in the management of severe chylous leaks.

Surgery for elastofibroma dorsi: optimizing the management of a benign tumor-an analysis of 70 cases.

BACKGROUND: Elastofibroma dorsi (ED) is a benign soft-tissue tumor of the chest wall located near the tip of the scapula. Clinical presentation includes swelling, pain and impairment of shoulder movements. The present literature relies only on few small case series. The aim of this study was to analyze the surgical management of ED, focusing on the debated topics regarding preoperative evaluation, operative technique, post-operative outcome and follow-up. METHODS: We conducted a single-center retrospective cohort analysis of patients operated for ED between 2003 and 2018. Diagnostic techniques were ultrasonography (US), computed tomography (CT-scan) and magnetic resonance imaging (MRI). CT-scan represented our preferred imaging study for preoperative assessment. Surgery was proposed for symptomatic and/or large lesions. Marginal excision through a muscle-sparing approach was performed. An open-door follow-up policy was adopted. All clinical, radiological, perioperative and pathological variables were matched in a univariate analysis. A multivariate analysis was performed to investigate risk factors for postoperative complications. Correlations analysis between radiological and pathological measurements of elastofibroma was conducted. RESULTS: Seventy elastofibromas were excised in 59 patients. Mean age was 59 years and female prevalence was 59%. All elastofibromas were completely resected with no recurrence. Postoperative complications rate was 17%. Complications were mild in most cases. At the univariate analysis, patients with body mass index (BMI) >25 had a longer operative time (P=0.048), patients on antiplatelet medications experienced a prolonged drainage time (P=0.006) and a higher rate of complications (P=0.038); the occurrence of complications resulted in prolonged drainage time (P=0.047) and length of stay (P=0.023). A BMI ≤25 was the only independent risk factor for postoperative morbidity (OR 8.71, P=0.024). CT-scan showed the highest correlation with pathological size (r=0.819), US the lowest (r=0.421). CONCLUSIONS: Marginal resection through a muscle-sparing approach is safe and effective for the treatment of ED. CT-scan can be adequate for preoperative assessment. Giving the benign nature of the lesion and the absence of recurrence after complete resection, an open-door follow-up may be appropriate.

In Vitro Biophysical and Biological Characterization of Lipid Nanoparticles Co-Encapsulating Oncosuppressors miR-199b-5p and miR-204-5p as Potentiators of Target Therapy in Metastatic Melanoma.

Uncontrolled MAPK signaling is the main oncogenic driver in metastatic melanomas bearing mutations in BRAF kinase. These tumors are currently treated with the combination of BRAF/MEK inhibitors (MAPKi), but this therapy is plagued by drug resistance. In this context we recently discovered that several microRNAs are involved in the development of drug resistance. In particular miR-204-5p and miR-199b-5p were found to function as antagonists of resistance because their enforced overexpression is able to inhibit melanoma cell growth in vitro either alone or in combination with MAPKi. However, the use of miRNAs in therapy is hampered by their rapid degradation in serum and biological fluids, as well as by the poor intracellular uptake. Here, we developed lipid nanoparticles (LNPs) encapsulating miR-204-5p, miR-199b-5p individually or in combination. We obtained LNPs with mean diameters < 200 nm and high miRNA encapsulation efficiency. These formulations were tested in vitro on several melanoma cell lines sensitive to MAPKi or rendered drug resistant. Our results show that LNPs encapsulating combinations of the two oncosuppressor miRNAs are highly efficient in impairing melanoma cell proliferation and viability, affect key signaling pathways involved in melanoma cell survival, and potentiate the efficacy of drugs inhibiting BRAF and MEK. These results warrant further assessment of the anti-tumor efficacy of oncosuppressor miRNAs encapsulating LNPs in in vivo tumor models.

Wound complication after modified Ravitch for pectus excavatum: A case of conservative treatment enhanced by pectoralis muscle transposition.

INTRODUCTION: Multiple surgical debridement sessions are mandatory before wound closure in cases of infection after a modified Ravitch procedure for pectus excavatum. Vacuum-assisted closure (VAC) is a well-established technical resource for treating complicated wounds; however, in cases of suspicion of bone infection, this approach is not enough to prevent bar removal. PRESENTATION OF THE CASE: We present a case of surgical wound dehiscence with hardware exposure in a patient who had undergone chondrosternoplasty for pectus excavatum. Several sessions of debridement (three) and VAC were applied every time. The final result was achieved without the necessity to remove the hardware; however, to avoid the risk of infection, a bilateral pectoralis muscle flap mobilization was performed as the final step after the surgical wound revisions, although this approach is suggested to be used during the modified Ravitch procedure. This approach allows for a significant reduction in late complications and improves morphological outcomes. DISCUSSION: In summary, the pectoralis muscle flap transposition is very useful not only for aesthetical results but also in combination with multiple surgical revisions for conservative management in case of wound infection during a modified Ravitch procedure. In our case, this technique was adopted after accurate care of the wound and before the final closure, which helps to maintain good vascularization and a very satisfying result. CONCLUSION: It is important to consider this approach during the modified Ravitch procedure, not only for better aesthetical results but also to prevent infections or wound dehiscence at the level of the bar.

Single cell analysis to dissect molecular heterogeneity and disease evolution in metastatic melanoma.

Originally described as interpatient variability, tumour heterogeneity has now been demonstrated to occur intrapatiently, within the same lesion, or in different lesions of the same patient. Tumour heterogeneity involves both genetic and epigenetic changes. Intrapatient heterogeneity is responsible for generating subpopulations of cancer cells which undergo clonal evolution with time. Tumour heterogeneity develops also as a consequence of the selective pressure imposed by the immune system. It has been demonstrated that tumour heterogeneity and different spatiotemporal interactions between all the cellular compontents within the tumour microenvironment lead to cancer adaptation and to therapeutic pressure. In this context, the recent advent of single cell analysis approaches which are able to better study tumour heterogeneity from the genomic, transcriptomic and proteomic standpoint represent a major technological breakthrough. In this review, using metastatic melanoma as a prototypical example, we will focus on applying single cell analyses to the study of clonal trajectories which guide the evolution of drug resistance to targeted therapy.

ErbB3 Phosphorylation as Central Event in Adaptive Resistance to Targeted Therapy in Metastatic Melanoma: Early Detection in CTCs during Therapy and Insights into Regulation by Autocrine Neuregulin.

In recent years the introduction of target therapies with BRAF and MEK inhibitors (MAPKi) and of immunotherapy with anti-CTLA-4 and anti-PD-1 monoclonal antibodies have dramatically improved survival of metastatic melanoma patients. Despite these changes drug resistance remains a major hurdle. Several mechanisms are at the basis of drug resistance. Particular attention has been devoted over the last years to unravel mechanisms at the basis of adaptive/non genetic resistance occurring in BRAF mutated melanomas upon treatment with to MAPKi. In this paper we focus on the involvement of activation of ErbB3 receptor following early exposure of melanoma cells to BRAF or MEK inhibitors, and the following induction of PI3K/AKT pathway. Although different mechanisms have been invoked in the past at the basis of this activation we show here with a combination of approaches that autocrine production of neuregulin by melanoma cells is a major factor responsible for ErbB3 phosphorylation and downstream AKT activation. Interestingly the kinetic of neuregulin production and of the ensuing ErbB3 phosphorylation is different in different melanoma cell lines which underscores the high degree of tumor heterogeneity. Moreover, heterogeneity is further highlighted by the evidence that in different cell lines neuregulin upregulation can occur at the transcriptional or at the post-transcritpional level. Finally we complement our study by showing with a liquid biopsy assay that circulating tumor cells (CTCs) from melanoma patients undergo upregulation of ErbB3 phosphorylation in vivo shortly after initiation of therapy.

Giant bulla or pneumothorax: How to distinguish.

BACKGROUND: The differential diagnosis between pneumothorax and giant bullae is thought to be straightforward but sometimes poses a challenge. CASE PRESENTATION: We present a case of a 54-year-old Caucasian man with a giant emphysematous bulla who underwent surgical resection. He had no smoking history and had previous pneumonia episodes. The surgery was free of complications, without air leaks, and he showed good ventilation of the lung. DISCUSSION: The main complications of bullae are pneumothorax, infection and hemorrhage. Pneumothorax is a serious complication in patients with compromised lung function. Therefore, it is very important to carefully distinguish bullae from pneumothorax to avoid iatrogenic pneumothorax in patients with bullous disease. CONCLUSION: We emphasize how to differentiate between giant bullae and pneumothorax utilizing history, physical examination, and radiological studies, including computed tomography (CT) scan.

Pectoralis Muscle Transposition in Association with the Ravitch Procedure in the Management of Severe Pectus Excavatum.

Pectus excavatum (PE) is the most common congenital chest wall deformity. PE is sometimes associated with cardiorespiratory impairment, but is often associated with psychological distress, especially for patients in their teenage years. Surgical repair of pectus deformities has been shown to improve both physical limitations and psychosocial well-being in children. The most common surgical approaches for PE treatment are the modified Ravitch technique and the minimally invasive Nuss technique. A technical modification of the Ravitch procedure, which includes bilateral mobilization and midline transposition of the pectoralis muscle flap, is presented here. METHODS: From 2010 to 2016, 12 patients were treated by a modified Ravitch procedure with bilateral mobilization and midline transposition of the pectoralis muscle flap for severe PE. Outcomes, morphological results, and complications were analyzed with respect to this new combined surgical approach. RESULTS: There was a statistically significant difference between pre- and postoperative values (P = 0.0025) of the Haller index at the 18-month follow-up, showing a significant morphological improvement for all treated patients. After surgery, no morbidity and mortality were noted. The mean hospital stay was 7 days, and all patients were discharged without major complications. CONCLUSION: This technique significantly improved patients' postoperative morphological outcomes and significantly reduced long-term complications, such as wound dehiscence, skin thinning, and hardware exposure.

Reprogramming miRNAs global expression orchestrates development of drug resistance in BRAF mutated melanoma.

Drug resistance imposes severe limitations to the efficacy of targeted therapy in BRAF-mutated metastatic melanoma. Although this issue has been mitigated by the development of combination therapies with BRAF plus MEK inhibitors, drug resistance inevitably occurs with time and results in clinical recurrences and untreatable disease. Hence, there is strong need of developing new combination therapies and non-invasive diagnostics for the early identification of drug-resistant patients. We report here that the development of drug resistance to BRAFi is dominated by a dynamic deregulation of a large population of miRNAs, leading to the alteration of cell intrinsic proliferation and survival pathways, as well as of proinflammatory and proangiogenic cues, where a prominent role is played by the miR-199b-5p/VEGF axis. Significant alterations of miRNA expression levels are detectable in tumor biopsies and plasma from patients after disease recurrence. Targeting these alterations blunts the development of drug resistance.

MicroRNAs in melanoma development and resistance to target therapy.

microRNAs constitute a complex class of pleiotropic post-transcriptional regulators of gene expression involved in the control of several physiologic and pathologic processes. Their mechanism of action is primarily based on the imperfect matching of a seed region located at the 5' end of a 21-23 nt sequence with a partially complementary sequence located in the 3' untranslated region of target mRNAs. This leads to inhibition of mRNA translation and eventually to its degradation. Individual miRNAs are capable of binding to several mRNAs and several miRNAs are capable of influencing the function of the same mRNAs. In recent years networks of miRNAs are emerging as capable of controlling key signaling pathways responsible for the growth and propagation of cancer cells. Furthermore several examples have been provided which highlight the involvement of miRNAs in the development of resistance to targeted drug therapies. In this review we provide an updated overview of the role of miRNAs in the development of melanoma and the identification of the main downstream pathways controlled by these miRNAs. Furthermore we discuss a group of miRNAs capable to influence through their respective up- or down-modulation the development of resistance to BRAF and MEK inhibitors.