The silver lining of the pandemic in surgical education: virtual surgical education and recommendations for best practices.

Virtual education is an evolving field within the realm of surgical training. Since the onset of the COVID-19 pandemic, the application of virtual technologies in surgical education has undergone significant exploration and advancement. While originally developed to supplement in-person curricula for the development of clinical decision-making, virtual surgical education has expanded into the realms of clinical decision-making, surgical, and non-surgical skills acquisition. This manuscript aims to discuss the various applications of virtual surgical education as well as the advantages and disadvantages associated with each education modality, while offering recommendations on best practices and future directions.

Is Routine Chest Radiography Necessary After Endobronchial Ultrasound-guided Fine Needle Aspiration?

BACKGROUND: Chest radiography is routinely performed after endobronchial ultrasound-guided fine needle aspiration (EBUS-FNA) to detect clinically occult pneumothorax. Because the established rate of postprocedure pneumothorax is low, this study sought to determine whether routine chest radiography can be safely eliminated and to ascertain the potential cost reduction with its omission. METHODS: Patients who underwent EBUS-FNA between January 1, 2017 and December 31, 2018 at Memorial Sloan Kettering Cancer Center (New York, NY) were retrospectively identified. Patient-related factors were summarized using descriptive statistics. Outcomes were compared using the χ2, Fisher exact, and analysis of variance tests. Univariate regression analysis was used to identify factors predictive of postprocedure pneumothorax. RESULTS: A total of 757 patients were included in the study: 72.4% (548 of 757) underwent routine chest radiography in the postanesthesia care unit. Clinically relevant or radiographically evident pneumothorax developed in 1.5% of patients (11 of 757). Of the patients who underwent chest radiography, 0.5% (3 of 548) required unplanned admission for postprocedure pneumothorax, and 0.2% (1 of 548) required tube thoracostomy. Of the 209 patients who did not undergo chest radiography, none experienced a clinically evident pneumothorax. In total, only 1 patient (0.1%) had symptomatic pneumothorax. The pneumothorax event rate was so low that no association with demographic or clinical factors and no predictive factors could be identified. The number of patients needed to be screened by chest radiography to identify 1 patient requiring deviation from routine management is 183. The potential total cost reduction if routine chest radiography had been eliminated was $33,950. CONCLUSIONS: The extremely low rate of postprocedure pneumothorax precluded informative statistical analysis. Routine chest radiography after EBUS-FNA may not be necessary, and its omission may confer a cost savings.

Novel EPHB4 Receptor Tyrosine Kinase Mutations and Kinomic Pathway Analysis in Lung Cancer.

Lung cancer outcomes remain poor despite the identification of several potential therapeutic targets. The EPHB4 receptor tyrosine kinase (RTK) has recently emerged as an oncogenic factor in many cancers, including lung cancer. Mutations of EPHB4 in lung cancers have previously been identified, though their significance remains unknown. Here, we report the identification of novel EPHB4 mutations that lead to putative structural alterations as well as increased cellular proliferation and motility. We also conducted a bioinformatic analysis of these mutations to demonstrate that they are mutually exclusive from other common RTK variants in lung cancer, that they correspond to analogous sites of other RTKs' variations in cancers, and that they are predicted to be oncogenic based on biochemical, evolutionary, and domain-function constraints. Finally, we show that EPHB4 mutations can induce broad changes in the kinome signature of lung cancer cells. Taken together, these data illuminate the role of EPHB4 in lung cancer and further identify EPHB4 as a potentially important therapeutic target.

Expression of the EPHB4 receptor tyrosine kinase in head and neck and renal malignancies--implications for solid tumors and potential for therapeutic inhibition.

Solid malignancies are often characterized by overexpression of various receptor tyrosine kinases (RTKs) against which many targeted therapies are currently in use and in active development. EPHB4 has recently emerged as a frequently overexpressed RTK in many types of cancer. Here, we demonstrate expression patterns of EPHB4 in two solid malignancies: squamous cell carcinoma of the head and neck (HNSCC) and renal cell carcinoma (RCC), by immunohistochemical analysis. We demonstrate the first association between EPHB4 expression and progression of HNSCC from normal tissue to dysplasia and to cancer. Interestingly, most RCC subtypes exhibited expression patterns that were opposite from that found in HNSCC, possibly owing to their unique biology and high degree of organ and tumor vasculature. Taken together, these results suggest a possible role for EPHB4 as a therapeutic target in these malignancies.

Podcasting as a novel way to communicate with medical school applicants.

Podcasting in medical education is becoming more widely used and may be a useful tool for communicating with applicants to medical school. Given recent trends in the popularity of podcasting and mobile media, we created a podcast to communicate more effectively with applicants to our medical school as well as with the broader premedical community. The purpose of this study was to characterize the listening habits and motivations of our audience and compare the podcast's benefits to those of other resources. We additionally sought to understand patterns by which our podcast was consumed by a premedical audience. We surveyed medical school applicants who interviewed at the University of Chicago Pritzker School of Medicine for matriculation in 2013. Forty-one percent of those surveyed had listened to the podcast prior to their interview. Only 12 % of listeners accessed the podcast using a mobile device. Ninety-two percent of listeners felt that it faithfully represented the medical school, and 81 % felt that listening would encourage the decision to matriculate. A majority of listeners responded that the podcast was more helpful than other traditional resources. This is the first use of podcasting in medical school admissions and represents a novel way to communicate with prospective students. Our findings demonstrate that podcasting can be an effective tool for communicating with applicants to medical school and highlight its usefulness in recruitment. This method of communication could be adopted by other medical schools to enhance the ways in which they inform their own prospective medical students.

The EphB4 receptor tyrosine kinase promotes lung cancer growth: a potential novel therapeutic target.

Despite progress in locoregional and systemic therapies, patient survival from lung cancer remains a challenge. Receptor tyrosine kinases are frequently implicated in lung cancer pathogenesis, and some tyrosine kinase inhibition strategies have been effective clinically. The EphB4 receptor tyrosine kinase has recently emerged as a potential target in several other cancers. We sought to systematically study the role of EphB4 in lung cancer. Here, we demonstrate that EphB4 is overexpressed 3-fold in lung tumors compared to paired normal tissues and frequently exhibits gene copy number increases in lung cancer. We also show that overexpression of EphB4 promotes cellular proliferation, colony formation, and motility, while EphB4 inhibition reduces cellular viability in vitro, halts the growth of established tumors in mouse xenograft models when used as a single-target strategy, and causes near-complete regression of established tumors when used in combination with paclitaxel. Taken together, these data suggest an important role for EphB4 as a potential novel therapeutic target in lung cancer. Clinical trials investigating the efficacy of anti-EphB4 therapies as well as combination therapy involving EphB4 inhibition may be warranted.

EphB4 as a therapeutic target in mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) often develops decades following exposure to asbestos. Current best therapy produces a response in only half of patients, and the median survival with this therapy remains under a year. A search for novel targets and therapeutics is underway, and recently identified targets include VEGF, Notch, and EphB4-Ephrin-B2. Each of these targets has dual activity, promoting tumor cell growth as well as tumor angiogenesis. METHODS: We investigated EphB4 expression in 39 human mesothelioma tissues by immunohistochemistry. Xenograft tumors established with human mesothelioma cells were treated with an EphB4 inhibitor (monomeric soluble EphB4 fused to human serum albumin, or sEphB4-HSA). The combinatorial effect of sEphB4-HSA and biologic agent was also studied. RESULTS: EphB4 was overexpressed in 72% of mesothelioma tissues evaluated, with 85% of epithelioid and 38% of sarcomatoid subtypes demonstrating overexpression. The EphB4 inhibitor sEphB4-HSA was highly active as a single agent to inhibit tumor growth, accompanied by tumor cell apoptosis and inhibition of PI3K and Src signaling. Combination of sEphB4-HSA and the anti-VEGF antibody (Bevacizumab) was superior to each agent alone and led to complete tumor regression. CONCLUSION: EphB4 is a potential therapeutic target in mesothelioma. Clinical investigation of sEphB4-HSA as a single agent and in combination with VEGF inhibitors is warranted.

Critical role for the receptor tyrosine kinase EPHB4 in esophageal cancers.

Esophageal cancer incidence is increasing and has few treatment options. In studying receptor tyrosine kinases associated with esophageal cancers, we have identified EPHB4 to be robustly overexpressed in cell lines and primary tumor tissues. In total, 94 squamous cell carcinoma, 82 adenocarcinoma, 25 dysplasia, 13 Barrett esophagus, and 25 adjacent or unrelated normal esophageal tissues were evaluated by immunohistochemistry. EPHB4 expression was significantly higher in all the different histologic categories than in adjacent normal tissues. In 13 esophageal cancer cell lines, 3 of the 9 SCC cell lines and 2 of the 4 adenocarcinomas expressed very high levels of EPHB4. An increased gene copy number ranging from 4 to 20 copies was identified in a subset of the overexpressing patient samples and cell lines. We have developed a novel 4-nitroquinoline 1-oxide (4-NQO)-induced mouse model of esophageal cancer that recapitulates the EPHB4 expression in humans. A specific small-molecule inhibitor of EPHB4 decreased cell viability in a time- and dose-dependent manner in 3 of the 4 cell lines tested. The small-molecule inhibitor and an EPHB4 siRNA also decreased cell migration (12%-40% closure in treated vs. 60%-80% in untreated), with decreased phosphorylation of various tyrosyl-containing proteins, EphB4, and its downstream target p125FAK. Finally, in a xenograft tumor model, an EPHB4 inhibitor abrogated tumor growth by approximately 60% compared with untreated control. EphB4 is robustly expressed and potentially serves as a novel biomarker for targeted therapy in esophageal cancers.

Proteomic characterization of non-small cell lung cancer in a comprehensive translational thoracic oncology database.

BACKGROUND: In recent years, there has been tremendous growth and interest in translational research, particularly in cancer biology. This area of study clearly establishes the connection between laboratory experimentation and practical human application. Though it is common for laboratory and clinical data regarding patient specimens to be maintained separately, the storage of such heterogeneous data in one database offers many benefits as it may facilitate more rapid accession of data and provide researchers access to greater numbers of tissue samples. DESCRIPTION: The Thoracic Oncology Program Database Project was developed to serve as a repository for well-annotated cancer specimen, clinical, genomic, and proteomic data obtained from tumor tissue studies. The TOPDP is not merely a library-it is a dynamic tool that may be used for data mining and exploratory analysis. Using the example of non-small cell lung cancer cases within the database, this study will demonstrate how clinical data may be combined with proteomic analyses of patient tissue samples in determining the functional relevance of protein over and under expression in this disease. Clinical data for 1323 patients with non-small cell lung cancer has been captured to date. Proteomic studies have been performed on tissue samples from 105 of these patients. These tissues have been analyzed for the expression of 33 different protein biomarkers using tissue microarrays. The expression of 15 potential biomarkers was found to be significantly higher in tumor versus matched normal tissue. Proteins belonging to the receptor tyrosine kinase family were particularly likely to be over expressed in tumor tissues. There was no difference in protein expression across various histologies or stages of non-small cell lung cancer. Though not differentially expressed between tumor and non-tumor tissues, the over expression of the glucocorticoid receptor (GR) was associated improved overall survival. However, this finding is preliminary and warrants further investigation. CONCLUSION: Though the database project is still under development, the application of such a database has the potential to enhance our understanding of cancer biology and will help researchers to identify targets to modify the course of thoracic malignancies.

EphA2 mutation in lung squamous cell carcinoma promotes increased cell survival, cell invasion, focal adhesions, and mammalian target of rapamycin activation.

Non-small cell lung cancer (NSCLC) has a poor prognosis and improved therapies are needed. Expression of EphA2 is increased in NSCLC metastases. In this study, we investigated EphA2 mutations in NSCLC and examined molecular pathways involved in NSCLC. Tumor and cell line DNA was sequenced. One EphA2 mutation was modeled by expression in BEAS2B cells, and functional and biochemical studies were conducted. A G391R mutation was detected in H2170 and 2/28 squamous cell carcinoma patient samples. EphA2 G391R caused constitutive activation of EphA2 with increased phosphorylation of Src, cortactin, and p130(Cas). Wild-type (WT) and G391R cells had 20 and 40% increased invasiveness; this was attenuated with knockdown of Src, cortactin, or p130(Cas). WT and G391R cells demonstrated a 70% increase in focal adhesion area. Mammalian target of rapamycin (mTOR) phosphorylation was increased in G391R cells with increased survival (55%) compared with WT (30%) and had increased sensitivity to rapamycin. A recurrent EphA2 mutation is present in lung squamous cell carcinoma and increases tumor invasion and survival through activation of focal adhesions and actin cytoskeletal regulatory proteins as well as mTOR. Further study of EphA2 as a therapeutic target is warranted.

MET/PKCbeta expression correlate with metastasis and inhibition is synergistic in lung cancer.

BACKGROUND: Treatment of non-small cell lung cancer (NSCLC) remains a difficult task in oncology. Targeted inhibition of oncogenic proteins is promising. In this study, we evaluate the expression of MET and PKCbeta and in vitro effects of their inhibition using SU11274 and enzastaurin (LY317615.HCl) respectively. MATERIALS AND METHODS: Patient samples were analyzed by immunohistochemistry for expression of PKCbeta and MET, utilizing tissue microarrays under an IRB-approved protocol. Expression of PKCbeta and MET was evaluated in cell lines by immunoblotting. Treatment with SU1174 against MET and enzastaurin against PKCbeta was performed in H1993 and H358 cell lines, and cell proliferation and downstream signaling (phosphorylation of MET, AKT, FAK, and GSK3beta) were evaluated by immunoblotting. Statistical analysis was performed using SPSS 16.0. RESULTS: Expression of MET positively correlated with lymph node metastases (p=.0004), whereas PKCbeta showed no correlation (p=0.204). MET and PKCbeta expression were also strongly correlated (p<0.001). Expression of MET was observed in 5/8 cell lines (H358, H1703, A549, H1993, H2170; absent from H522, H661, or SW1573), whereas PKCbeta expression was observed in 8/8 cell lines. Cell proliferation was significantly impaired by treatment with SU11274 and enzastaurin, and their effects were synergistic in combination (CI=0.32 and 0.09). Phosphorylation of MET, FAK, AKT, and GSK3beta were strongly inhibited with both agents in combination. CONCLUSIONS: Concomitant inhibition of MET and PKCbeta significantly increased cytotoxicity in vitro against NSCLC, disrupting important downstream signaling pathways. Further evaluation in animal models is warranted.