Sequential binary gene ratio tests define a novel molecular diagnostic strategy for malignant pleural mesothelioma

Genes and Pathways Involved in the Progression of Malignant Pleural Mesothelioma: A Meta-analysis of Genome-Wide Expression Studies

Malignant pleural mesothelioma (MPM) is a rare and aggressive neoplasm of the pleural tissue that lines the lungs and is mainly associated with long latency from asbestos exposure. This tumor has no effective therapeutic opportunities nowadays and has a very low five-year survival rate. In this sense, identifying molecular events that trigger the development and progression of this tumor is highly important to establish new and potentially effective treatments. We conducted a meta-analysis of genome-wide expression studies publicly available at the Gene Expression Omnibus (GEO) and ArrayExpress databases. The differentially expressed genes (DEGs) were identified, and we performed functional enrichment analysis and protein-protein interaction networks (PPINs) to gain insight into the biological mechanisms underlying these genes. Additionally, we constructed survival prediction models for selected DEGs and predicted the minimum drug inhibition concentration of anticancer drugs for MPM. In total, 115 MPM tumor transcriptomes and 26 pleural tissue controls were analyzed. We identified 1046 upregulated DEGs in the MPM samples. Cellular signaling categories in tumor samples were associated with the TNF, PI3K-Akt, and AMPK pathways. The inflammatory response, regulation of cell migration, and regulation of angiogenesis were overrepresented biological processes. Expression of SOX17 and TACC1 were associated with reduced survival rates. This meta-analysis identified a list of DEGs in MPM tumors, cancer-related signaling pathways, and biological processes that were overrepresented in MPM samples. Some therapeutic targets to treat MPM are suggested, and the prognostic potential of key genes is shown.

KRAS signaling in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) arises from mesothelial cells lining the pleural cavity of asbestos‐exposed individuals and rapidly leads to death. MPM harbors loss‐of‐function mutations in BAP1, NF2, CDKN2A, and TP53, but isolated deletion of these genes alone in mice does not cause MPM and mouse models of the disease are sparse. Here, we show that a proportion of human MPM harbor point mutations, copy number alterations, and overexpression of KRAS with or without TP53 changes. These are likely pathogenic, since ectopic expression of mutant KRAS^G12D in the pleural mesothelium of conditional mice causes epithelioid MPM and cooperates with TP53 deletion to drive a more aggressive disease form with biphasic features and pleural effusions. Murine MPM cell lines derived from these tumors carry the initiating KRAS^G12D lesions, secondary Bap1 alterations, and human MPM‐like gene expression profiles. Moreover, they are transplantable and actionable by KRAS inhibition. Our results indicate that KRAS alterations alone or in accomplice with TP53 alterations likely play an important and underestimated role in a proportion of patients with MPM, which warrants further exploration.

Four Immune-Related Genes (FN1, UGCG, CHPF2 and THBS2) as Potential Diagnostic and Prognostic Biomarkers for Carbon Nanotube-Induced Mesothelioma

Background

Malignant pleural mesothelioma (MPM), a highly aggressive cancer, was mainly attributed to asbestos exposure. Carbon nanotubes (CNTs) share similar negative features to asbestos, provoking concerns about their contribution to MPM. This study was used to identify genes associated with CNT-induced MPM.

Methods

Microarray datasets were available in the Gene Expression Omnibus database. The limma method was used to identify differentially expressed genes (DEGs) in CNT-exposed MeT5A cells (GSE48855) or mice (GSE51636). Weighted correlation network analysis (WGCNA) and protein–protein interaction (PPI) network construction were conducted to screen hub DEGs. The mRNA expression levels of hub DEGs were validated on MPM samples of GSE51024, GSE2549 and GSE42977 datasets, and their diagnostic efficacy was determined by receiver operating characteristic curve analysis. The prognostic values of hub DEGs were assessed using online tools based on The Cancer Genome Atlas data. Their functions were annotated by Database for Annotation, Visualization and Integrated Discovery (DAVID) enrichment and correlation with immune cells and markers.

Results

WGCNA identified that two modules were associated with disease status. Thirty-one common DEGs in the GSE48855 and GSE51636 datasets were overlapped with the genes in these two modules. Twenty of them had a high degree centrality (≥4) in the PPI network. Four DEGs (FN1, fibronectin 1; UGCG, UDP-glucose ceramide glucosyltransferase; CHPF2, chondroitin polymerizing factor 2; and THBS2, thrombospondin 2) could predict the overall survival, and they were confirmed to be upregulated in MPM samples compared with controls. Also, they could effectively predict the MPM risk, with an overall accuracy of >0.9. DAVID analysis revealed FN1, CHPF2 and THBS2 functioned in cell-ECM interactions; UGCG influenced glycosphingolipid metabolism. All genes were positively associated with infiltrating levels of immune cells (macrophages or dendritic cells) and the expression of the dendritic cell marker (NRP1, neuropilin 1).

Conclusion

These four immune-related genes represent potential biomarkers for monitoring CNT-induced MPM and predicting the prognosis.

Malignant Pleural Mesothelioma Interactome with 364 Novel Protein-Protein Interactions

Malignant pleural mesothelioma (MPM) is an aggressive cancer affecting the outer lining of the lung, with a median survival of less than one year. We constructed an 'MPM interactome' with over 300 computationally predicted protein-protein interactions (PPIs) and over 2400 known PPIs of 62 literature-curated genes whose activity affects MPM. Known PPIs of the 62 MPM associated genes were derived from Biological General Repository for Interaction Datasets (BioGRID) and Human Protein Reference Database (HPRD). Novel PPIs were predicted by applying the HiPPIP algorithm, which computes features of protein pairs such as cellular localization, molecular function, biological process membership, genomic location of the gene, and gene expression in microarray experiments, and classifies the pairwise features as interacting or non-interacting based on a random forest model. We validated five novel predicted PPIs experimentally. The interactome is significantly enriched with genes differentially ex-pressed in MPM tumors compared with normal pleura and with other thoracic tumors, genes whose high expression has been correlated with unfavorable prognosis in lung cancer, genes differentially expressed on crocidolite exposure, and exosome-derived proteins identified from malignant mesothelioma cell lines. 28 of the interactors of MPM proteins are targets of 147 U.S. Food and Drug Administration (FDA)-approved drugs. By comparing disease-associated versus drug-induced differential expression profiles, we identified five potentially repurposable drugs, namely cabazitaxel, primaquine, pyrimethamine, trimethoprim and gliclazide. Preclinical studies may be con-ducted in vitro to validate these computational results. Interactome analysis of disease-associated genes is a powerful approach with high translational impact. It shows how MPM-associated genes identified by various high throughput studies are functionally linked, leading to clinically translatable results such as repurposed drugs. The PPIs are made available on a webserver with interactive user interface, visualization and advanced search capabilities.

Identification of Overexpressed Genes in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene-expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients' overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E-selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small-molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer-driving role of the targets herewith identified.

Association of RERG Expression with Female Survival Advantage in Malignant Pleural Mesothelioma

Sex differences in incidence, prognosis, and treatment response have been described for many cancers. In malignant pleural mesothelioma (MPM), a lethal disease associated with asbestos exposure, men outnumber women 4 to 1, but women consistently live longer than men following surgery-based therapy. This study investigated whether tumor expression of genes associated with estrogen signaling could potentially explain observed survival differences. Two microarray datasets of MPM tumors were analyzed to discover estrogen-related genes associated with survival. A validation cohort of MPM tumors was selected to balance the numbers of men and women and control for competing prognostic influences. The RAS like estrogen regulated growth inhibitor (RERG) gene was identified as the most differentially-expressed estrogen-related gene in these tumors and predicted prognosis in discovery datasets. In the sex-matched validation cohort, low RERG expression was significantly associated with increased risk of death among women. No association between RERG expression and survival was found among men, and no relationship between estrogen receptor protein or gene expression and survival was found for either sex. Additional investigations are needed to elucidate the molecular mechanisms underlying this association and its sex specificity.

COL1A1 Is a Potential Prognostic Biomarker and Correlated with Immune Infiltration in Mesothelioma

Objective

Mesothelioma (MESO) is a rare tumor derived from mesothelium cells. The aim of this study was to explore key candidate genes and potential molecular mechanisms for mesothelioma through bioinformatics analysis.

Methods

The MESO expression profiles came from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. The differences in the infiltration levels of immune cells between MESO and normal tissues were assessed using CIBERSORT. Differentially expressed genes (DEGs) were identified by comprehensive analysis of multiple datasets. A protein-protein interaction (PPI) network was constructed, and a hub gene COL1A1 was selected for MESO. The expression and mutation of COL1A1 in MESO were analyzed in the cBioPortal database. The correlation between COL1A1 expression and immune cell infiltration was evaluated using the TIMER database. Gene Set Enrichment Analysis (GSEA) of COL1A1 was then performed. Finally, Kaplan-Meier survival analysis was presented to predict the survival times between high and low COL1A1 expression groups for MESO patients.

Results

There were distinct differences in the infiltration levels of immune cells between MESO and normal tissues. A total of 118 DEGs were identified by comprehensively analyzing three expression profile datasets. COL1A1, a hub gene, was identified to be highly expressed in MESO compared to normal tissues. COL1A1 genetic mutation occurred in 9% of MESO samples, and amplification was the most common type of mutation. COL1A1 expression was significantly correlated to the infiltration levels of CD4+ T cells, macrophages, and neutrophils. GSEA results indicated that COL1A1 could be involved in key biological processes and pathways like extracellular matrix and PI3K-Akt pathway. Patients with high COL1A1 expression usually experienced shorten overall survival time than those with its low expression.

Conclusion

Our findings revealed that COL1A1 could become a potential prognostic biomarker for MESO, which was significantly related to immune cell infiltration.

Identification of Potential Hub Genes and Therapeutic Drugs in Malignant Pleural Mesothelioma by Integrated Bioinformatics Analysis

INTRODUCTION

Malignant pleural mesothelioma (MPM) is closely linked to asbestos exposure and is an extremely aggressive tumor with poor prognosis.

OBJECTIVE

Our study aimed to elucidate hub genes and potential drugs in MPM by integrated bioinformatics analysis.

METHODS

GSE42977 was download from the Gene Expression Omnibus (GEO) database; the differentially expressed genes (DEGs) with adj.p value <0.05 and |logFC| ≥2 were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed by DAVID database. The STRING database was used to construct a protein-protein interaction network, and modules analysis and hub genes acquisition were performed by Cytoscape. The Gene Expression Profiling Interactive Analysis (GEPIA) database was used to assess the impact of hub genes on the prognosis of MPM patients. The Drug-Gene Interaction database (DGIdb) was used to select the related drugs.

RESULTS

A total of 169 upregulated and 70 downregulated DEGs were identified. These DEGs are enriched in the pathway of extracellular matrix-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, and PPAR signaling pathway. Finally, 10 hub genes (CDC20, CDK1, UBE2C, TOP2A, CCNB2, NUSAP1, KIF20A, AURKA, CEP55, and ASPM) were identified, which are considered to be closely related to the poor prognosis of MPM. In addition, 119 related drugs that may have a therapeutic effect on MPM were filtered out.

CONCLUSION

These discovered genes and small-molecule drugs provide some new ideas for further research on MPM.

Possible reversibility between epithelioid and sarcomatoid types of mesothelioma is independent of ERC/mesothelin expression

Background

Mesothelioma is histologically divided into three subgroups: epithelioid, sarcomatoid, and biphasic types. The epithelioid or sarcomatoid type is morphologically defined by polygonal or spindle-like forms of cells, respectively. The biphasic type consists of both components. It is not yet understood how histological differentiation of mesothelioma is regulated. ERC/mesothelin is expressed in most cases of the epithelioid type, but not in the sarcomatoid type of mesothelioma. Consequently, its expression is well correlated to the histological subtype. We hypothesized that ERC/mesothelin expression influences the histological differentiation of mesothelioma, and tested this hypothesis.

Methods

We performed studies using the overexpression or knockdown of ERC/mesothelin in mesothelioma cells to examine its effect on cellular morphology, growth kinetics, or migration/invasion activity, in vitro. We then transplanted ERC/mesothelin-overexpressing and control cells into the intraperitoneal space of mice. We examined the effect of ERC/mesothelin overexpression on mouse survival and tumor phenotype.

Results

In vitro cell culture manipulations of ERC/mesothelin expression did not affect cellular morphology or proliferation, although its overexpression enhanced cellular adhesion and the migration/invasion activity of mesothelioma cells. The survival rate of mice following intraperitoneal transplantation of ERC/mesothelin-overexpressing mesothelioma cells was significantly lower than that of mice with control cells. The histological evaluation of the tumors, however, did not show any morphological difference between two groups, and our hypothesis was not validated. Unexpectedly, both groups (ERC/mesothelin-overexpressing and control) of mesothelioma cells that were morphologically monophasic and spindle-like in vitro differentiated into a biphasic type consisting of polygonal and spindle-like components in the transplanted tumor, irrespective of ERC/mesothelin expression.

Conclusions

These results suggested that the histological transition of mesothelioma between epithelioid and sarcomatoid types may be reversible and regulated not by ERC/mesothelin, but by other unknown mechanisms.

Evaluation of gene expression levels in the diagnosis of lung adenocarcinoma and malignant pleural mesothelioma

Background

This study aims to evaluate gene expression levels in the diagnosis of lung adenocarcinoma and malignant pleural mesothelioma both which have a distinct treatment and prognosis.

Methods

Between January 2012 and January 2014, 12 newly diagnosed patients with a lung adenocarcinoma, 12 patients with malignant pleural mesothelioma, and eight healthy individuals as the control group were included. After treatment of the fresh samples of lung adenocarcinoma stored at -80°C for ribonucleic acid isolation, and paraffin-embedded tissues of patients with malignant pleural mesothelioma were deparaffinized, complementary deoxyribonucleic acid synthesis and expression of 84 genes associated with deoxyribonucleic acid repair were analyzed via real-time polymerase chain reaction assay. According to the expression of tumor cells, expression of each fold change was calculated.

Results

The BRCA1, BRCA2, CDK7, MLH3, MSH4, NEIL3, SMUG1, UNG, XRCC2, and XRCC4 genes showed more than five-fold higher expression in the patients with lung adenocarcinomas, compared to the control group. The patients with malignant pleural mesothelioma showed a five-fold higher expression in the APEX2, BRCA1, BRCA2, CDK7, MLH1, MLH3, MSH3, MSH4, NEIL3, PARP2, PARP3, PMS1, RAD50, RAD51, RAD51B, RAD51D, RAD52, RPA3, SMUG1, UNG, XPA, XRCC2, and XRCC4 genes, compared to the control group. Comparing malignant pleural mesothelioma with lung adenocarcinoma cases, we found that CDK7, MLH1, TREX1, PRKDC, XPA, PMS1, UNG, and RPA3 genes were overexpressed.

Conclusion

Our study results showed differences between expression profiles of deoxyribonucleic acid repair genes in lung adenocarcinoma and malignant pleural mesothelioma cells. Based on our study results, we suggest that TREX1, PRKDC, and PMS1 genes may play a key role in the differential diagnosis of these two entities.

Malignant pleural mesothelioma and mesothelial hyperplasia: A new molecular tool for the differential diagnosis

Malignant pleural mesothelioma (MPM) is a rare asbestos related cancer, aggressive and unresponsive to therapies. Histological examination of pleural lesions is the gold standard of MPM diagnosis, although it is sometimes hard to discriminate the epithelioid type of MPM from benign mesothelial hyperplasia (MH).This work aims to define a new molecular tool for the differential diagnosis of MPM, using the expression profile of 117 genes deregulated in this tumour.The gene expression analysis was performed by nanoString System on tumour tissues from 36 epithelioid MPM and 17 MH patients, and on 14 mesothelial pleural samples analysed in a blind way. Data analysis included raw nanoString data normalization, unsupervised cluster analysis by Pearson correlation, non-parametric Mann Whitney U-test and molecular classification by the Uncorrelated Shrunken Centroid (USC) Algorithm.The Mann-Whitney U-test found 35 genes upregulated and 31 downregulated in MPM. The unsupervised cluster analysis revealed two clusters, one composed only of MPM and one only of MH samples, thus revealing class-specific gene profiles. The Uncorrelated Shrunken Centroid algorithm identified two classifiers, one including 22 genes and the other 40 genes, able to properly classify all the samples as benign or malignant using gene expression data; both classifiers were also able to correctly determine, in a blind analysis, the diagnostic categories of all the 14 unknown samples.In conclusion we delineated a diagnostic tool combining molecular data (gene expression) and computational analysis (USC algorithm), which can be applied in the clinical practice for the differential diagnosis of MPM.

Molecular markers and new diagnostic methods to differentiate malignant from benign mesothelial pleural proliferations: a literature review

Malignant pleural mesothelioma (MPM) is an aggressive tumor associated with asbestos exposure. Histopathological analysis of pleural tissues is the gold standard for diagnosis; however, it can be difficult to differentiate malignant from benign pleural lesions. The purpose of this review is to describe the most important biomarkers and new diagnostic tools suggested for this differential diagnosis. There are many studies concerning the separation between MPM and benign pleural proliferations from both pleural tissues or effusions; most of them are based on the evaluation of one or few biomarkers by immunohistochemistry (IHC) or enzyme-linked immunosorbent assays (ELISAs), whereas others focused on the identification of MPM signatures given by microRNA (miRNA) or gene expression profiles as well as on the combination of molecular data and classification algorithms. None of the reported biomarkers showed adequate diagnostic accuracy, except for p16 [evaluated by fluorescent in situ hybridization (FISH)] and BAP1 (evaluated by IHC), both biomarkers are recommended by the International Mesothelioma Interest Group guidelines for histological and cytological diagnosis. BAP1 and p16 showed a specificity of 100% in discerning malignant from benign lesions because they are exclusively unexpressed or deleted in MPM. However, their sensitivity, even when used together, is not completely sufficient, and absence of their alterations cannot confirm the benign nature of the lesion. Recently, the availability of new techniques and increasing knowledge regarding MPM genetics led to the definition of some molecular panels, including genes or miRNAs specifically deregulated in MPM, that are extremely valuable for differential diagnosis. Moreover, the development of classification algorithms is facilitating the application of molecular data for clinical practice. Data regarding new diagnostic tools and MPM signatures are absolutely promising; however, before their application in clinical practice, a prospective validation is necessary, as these approaches could surely improve the differential diagnosis between malignant and benign pleural lesions.

BAP1, a tumor suppressor gene driving malignant mesothelioma

Like cancer generally, malignant mesothelioma (MM) is a genetic disease at the cellular level. DNA copy number analysis of mesothelioma specimens has revealed a number of recurrent sites of chromosomal loss, including 3p21.1, 9p21.3, and 22q12.2. The key inactivated driver genes located at 9p21.1 and 22q12.2 were discovered two decades ago as being the tumor suppressor loci CDKN2A and NF2, respectively. Only relatively recently was the BAP1 gene determined to be the driver gene at 3p21.1 that is somatically inactivated. In 2011, we reported germline mutations in BAP1 in two families with a high incidence of mesothelioma and other cancers such as uveal melanoma (UM). As a result of a flurry of research activity over the last 5-6 years, the BAP1 gene is now firmly linked causally to a novel tumor predisposition syndrome (TPDS) characterized by increased susceptibility to mesothelioma, UM, cutaneous melanoma (CM) and benign melanocytic tumors, as well as several other cancer types. Moreover, results from recent in vivo studies with genetically engineered Bap1-mutant mouse models and new functional studies have provided intriguing biological insights regarding BAP1's role in tumorigenesis. These and other recent findings offer new possibilities for novel preventative and therapeutic strategies for MM patients.

Plasma Biomarker Enrichment of Clinical Prognostic Indices in Malignant Pleural Mesothelioma

OBJECTIVES

Prognostic models for malignant pleural mesothelioma (MPM) are needed to prevent potentially futile outcomes. We combined MPM plasma biomarkers with validated clinical prognostic indices to determine whether stratification of risk for death in 194 patients with MPM improved.

METHODS

Individuals were recruited from three different centers: a discovery cohort (83 patients with MPM) created by combining patients from two U.S. centers and a separate, independent cohort from Canada (111 patients with MPM). Univariable and multivariable analyses were performed on the initial discovery and independent cohorts separately. In the multivariable analyses, prognostic factors were adjusted for the European Organisation for Research and Treatment of Cancer (EORTC) prognostic index (PI) of mesothelioma. The prognostic significance of adding plasma biomarker data to the PI was determined by using the likelihood ratio test, comparing models with and without the addition of biomarker to the clinical PI. The predictive ability of the biomarker was then assessed formally using Harrell's C-index by applying the fitted model variables of the discovery cohort to the second, independent cohort, including and not including the biomarker with the PI.

RESULTS

Higher levels of osteopontin and mesothelin were individually associated with worse prognosis after adjusting for the PI. In the independent cohort, incorporating either plasma osteopontin or mesothelin into the baseline predictive PI model substantively and statistically significantly improved Harrell's C-statistic. In the final prognostic model, log-osteopontin, EORTC clinical prognostic index, and hemoglobin remained as independently significant predictors and the entire prognostic model improved the optimism-corrected Harrell's C-index significantly, from 0.718 (0.67-0.77) to 0.801 (0.77-0.84).

CONCLUSIONS

These data suggest a possible role for preoperative plasma biomarkers to improve the prognostic capability of the EORTC PI of MPM.

Five years update on relationships between malignant pleural mesothelioma and exposure to asbestos and other elongated mineral particles

Despite the reduction of global asbestos consumption and production due to the ban or restriction of asbestos uses in more than 50 countries since the 1970s, malignant mesothelioma remains a disease of concern. Asbestos is still used, imported, and exported in several countries, and the number of mesothelioma deaths may be expected to increase in the next decades in these countries. Asbestos exposure is the main risk factor for malignant pleural mesothelioma, but other types of exposures are linked to the occurrence of this type of cancer. Although recent treatments improve the quality of life of patients with mesothelioma, malignant pleural mesothelioma remains an aggressive disease. Recent treatments have not resulted in appreciable improvement in survival, and thus development of more efficient therapies is urgently needed. The development of novel therapeutic strategies is dependent on our level of knowledge of the physiopathological and molecular changes that mesothelial cells acquired during the neoplastic process. During the past 5 years, new findings have been published on the etiology, epidemiology, molecular changes, and innovative treatments of malignant pleural mesothelioma. This review aims to update the findings of recent investigations on etiology, epidemiology, and molecular changes with a focus on (1) attributable risk of asbestos exposure in men and women and (2) coexposure to other minerals and other elongated mineral particles or high aspect ratio nanoparticles. Recent data obtained on genomic and gene alterations, pathways deregulations, and predisposing factors are summarized.

Surgery for malignant pleural mesothelioma

Malignant pleural mesothelioma is a locally aggressive asbestos-related cancer that has a worldwide distribution and an overall poor prognosis. The average median survival for patients receiving the current best nonsurgical therapy, cisplatin/pemetrexed chemotherapy, is between 7 and 13 months. In selected patients with early stage disease and favorable tumor characteristics, aggressive surgical management in combination with adjuvant or neoadjuvant therapy extends survival in up to 20% of patients. Despite the benefits of surgery for mesothelioma, many patients are not suitable for operative intervention due to advanced stage disease at presentation or the inability to tolerate aggressive surgical resection. The frontiers of mesothelioma research and treatment include an urgent search for biomarkers that can reliably detect early stage cancer in at-risk populations, clinical tests or indices that can reliably predict prognosis among surgical candidates and the development of efficacious drugs and targeted therapies that offer more durable local disease control.