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Renal cell carcinoma (RCC) is arguably the deadliest form of genitourinary malignancy and is nowadays viewed as a heterogeneous series of cancers, with the same origin but fundamentally different metabolisms and clinical behaviors. Immunohistochemistry (IHC) is increasingly necessary for RCC subtyping and definitive diagnosis. WT1 is a complex gene involved in carcinogenesis. To address reporting heterogeneity and WT1 IHC standardization, we used a recent N-terminus targeted monoclonal antibody (clone WT49) to evaluate WT1 protein expression in 56 adult RCC (aRCC) cases. This is the largest WT1 IHC investigation focusing exclusively on aRCCs and the first report on clone WT49 staining in aRCCs. We found seven (12.5%) positive cases, all clear cell RCCs, showing exclusively nuclear staining for WT1. We did not disregard cytoplasmic staining in any of the negative cases. Extratumoral fibroblasts, connecting tubules and intratumoral endothelial cells showed the same exclusively nuclear WT1 staining pattern. We reviewed WT1 expression patterns in aRCCs and the possible explanatory underlying metabolomics. For now, WT1 protein expression in aRCCs is insufficiently investigated, with significant discrepancies in the little data reported. Emerging WT1-targeted RCC immunotherapy will require adequate case selection and sustained efforts to standardize the quantification of tumor-associated antigens for aRCC and its many subtypes.

Introduction: The effect of tiredness has been proved for the surgeons' musculature performing laparoscopic or robotic procedures (physical stress). Mental stress after robotic surgery has been reported as well. It is still unclear how much the surgical skills are altered and which types of skills are more affected at the final steps of long, complex robotic surgical procedures., Aim: To evaluate to what extent the surgeon's skills are influenced by long procedures, using the objective assessment of different surgical skills by a virtual reality robotic simulator., Material and Methods: Fifteen surgeons were asked to perform a continuous 4 h virtual robotic surgical simulator training session. At the beginning of simulator training and at the end of each of the 4 h of training, three exercises of increasing difficulty were selected to be performed in order to assess the surgeons' skills., Results: There were statistically significant differences between the initial and final overall scores for all the three exercises, the final outcomes being inferior. The specific metrics for each exercise slightly improved within 1 h from the beginning and thereafter decreased to a statistically significantly inferior value., Conclusions: The specific metrics on the virtual reality robotic surgical simulator were altered after a 4-hour console training period. Further larger and more complex studies are necessary to evaluate the translation from the simulator to real-life robotic surgery., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2020 Fundacja Videochirurgii.)

Introduction: Robotic surgery is widely used in many surgical specialities, and there has been no study to assess the impact of sleep deprivation on the complex environment of robotic surgery., Aim: To compare specific metrics of selected robotic simulator exercises on sleep-deprived and non-sleep-deprived surgical residents., Material and Methods: We enrolled 20 volunteers, residents in surgery, evaluated before and after an 18-hour overnight shift, regarding their results on virtual robotic surgery simulator - the sleep deprivation (SD) group. As a control group, the same subjects were evaluated 5-7 days after the post-shift evaluation, without having a shift overnight and at least 7 h of sleep the previous night - the non-sleep-deprivation (nSD) group., Results: A statistically significant difference between the pre-shift and post-shift overall results for all exercises in the SD group and no statistical differences for the nSD group were observed. As the difficulty of the exercises increased, statistical differences were observed on specific metrics for all exercises between the pre-shift and post-shift as well as between the post-shift and the morning after a normal sleep period overnight. In a subgroup analysis, the overall results revealed a stronger statistical difference between pre-shift and post-shift for residents with more intense sleep deprivation (< 3 h of sleep vs. > 3 h of sleep)., Conclusions: Sleep deprivation leads to impairment of surgical skills assessed by robotic virtual simulator. The more complex and skill demanding the exercise, the higher the difference between sleep deprived and non-deprived residents., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2019 Fundacja Videochirurgii.)

Background/aim: Studies developed in the field of platelet-derived growth factors/platelet-derived growth factor receptors (PDGFs/PDGFRs) inhibition have focused on the therapeutic effects on tumor cells, neglecting their potential effects on tumor blood vessels. We herein propose a differential and critic assessment of platelet-derived growth factor B (PDGF-B) and platelet-derived growth factor receptor β (PDGFRβ) in renal cell carcinoma, correlated with the four main vascular patterns previously reported by our team., Materials and Methods: PDGF-B and PDGFRβ were evaluated on 50 archival paraffin embedded specimens related to vascular endothelial growth factor (VEGF), its inhibitory isoform VEGF165b and vascular patterns., Results and Conclusion: Our results support the involvement of VEGF165b in the phosphorylation of PDGFRβ with an inhibitory effect on endothelial proliferation and migration. The simultaneous action of PDGF-B/PDGFRβ and VEGF165b on the same type of receptor may explain the resistance to antiangiogenic therapy, which depends on the degree of modulation of PDGFRβ phosphorylation., (Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

The present study proposes a classification of renal cancer tumor blood vessels according to their morphology and maturation grade. We identified four vascular patterns: reticular, diffuse, fasciculated and trabecular. The reticular pattern was present in 63% of cases, being characterized by the predominance of mature CD34+/SMAct+ tumor vessels, highly interconnected. For this pattern, 74% of cases had vascular invasion, and a significant correlation was observed between tumor grade and immature state of tumor vessels (p = 0.022). The diffuse pattern was observed in 23% of cases and was characterized by non-interconnected vessels predominantly of mature CD34+/SMAct+ type and vascular invasion in 64% of cases. Only 8% of cases, had a fasciculate model of vessels distribution, all of them being of mature type, located in the connective axis of papillary renal tumors. For this pattern vascular invasion was found in 50% of cases. In 6% of cases a trabecular pattern was observed and the lowest rate of vascular invasion was registered. We defined here four distinct vascular patterns in renal cell carcinomas showing a strong impact on vascular invasion. A complete morphological and molecular characterization of tumor vessels would be beneficial in elucidating the mechanisms that underlie the ineffectiveness of antiangiogenic/antitumor therapies.

Rare and inconsistent data are reported for chorioallantoic tumor models of renal cell carcinoma and none of them has used endostatin as an inhibitory agent of tumor development. We aimed to perform a comparative analysis of tumor cells and blood vessels from renal cell carcinoma on endostatin-treated and non-treated chorioallantoic membrane (CAM) implants by the assessment of endoglin, vascular endothelial growth factor (VEGF) and smooth muscle actin expression. Endostatin triple action on tumor, endothelial and perivascular cells was observed in the present study. Differential impact of endostatin treatment on intratumor and peritumor blood vessels was noticed on the VEGF expression and behaviour of tumor cells between clear cell and papillary components of RCC. Based on our findings, a high tumor heterogenity response to endostatin has been highlighted. Interplay between VEGF, endoglin and endostatin in RCC could support a combined targeted therapy to improve prognosis of patients with RCC and reduce therapy resistance often developed by monotherapy., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)