Characterization of colibactin-associated mutational signature in an Asian oral squamous cell carcinoma and in other mucosal tumor types.

Mutational signatures can reveal the history of mutagenic processes that cells were exposed to before and during tumorigenesis. We expect that as-yet-undiscovered mutational processes will shed further light on mutagenesis leading to carcinogenesis. With this in mind, we analyzed the mutational spectra of 36 Asian oral squamous cell carcinomas. The mutational spectra of two samples from patients who presented with oral bacterial infections showed novel mutational signatures. One of these novel signatures, SBS_AnT, is characterized by a preponderance of thymine mutations, strong transcriptional strand bias, and enrichment for adenines in the 4 bp 5' of mutation sites. The mutational signature described in this manuscript was shown to be caused by colibactin, a bacterial mutagen produced by E. coli carrying the pks-island. Examination of publicly available sequencing data revealed SBS_AnT in 25 tumors from several mucosal tissue types, expanding the list of tissues in which this mutational signature is observed.

Analysis of T cell receptor clonotypes in tumor microenvironment identifies shared cancer-type-specific signatures.

Despite the conventional view that a truly random V(D)J recombination process should generate a highly diverse immune repertoire, emerging reports suggest that there is a certain bias toward the generation of shared/public immune receptor chains. These studies were performed in viral diseases where public T cell receptors (TCR) appear to confer better protective responses. Selective pressures generating common TCR clonotypes are currently not well understood, but it is believed that they confer a growth advantage. As very little is known about public TCR clonotypes in cancer, here we set out to determine the extent of shared TCR clonotypes in the intra-tumor microenvironments of virus- and non-virus-driven head and neck cancers using TCR sequencing. We report that tumor-infiltrating T cell clonotypes were indeed shared across individuals with the same cancer type, where the majority of shared sequences were specific to the cancer type (i.e., viral versus non-viral). These shared clonotypes were not particularly enriched in EBV-associated nasopharynx cancer but, in both cancers, exhibited distinct characteristics, namely shorter CDR3 lengths, restricted V- and J-gene usages, and also demonstrated convergent V(D)J recombination. Many of these shared TCRs were expressed in patients with a shared HLA background. Pattern recognition of CDR3 amino acid sequences revealed strong convergence to specific pattern motifs, and these motifs were uniquely found to each cancer type. This suggests that they may be enriched for specificity to common antigens found in the tumor microenvironment of different cancers. The identification of shared TCRs in infiltrating tumor T cells not only adds to our understanding of the tumor-adaptive immune recognition but could also serve as disease-specific biomarkers and guide the development of future immunotherapies.

Early quality of life outcomes after surgery in head and neck cancer survivors with EORTC QLQ-C30 and EORTC QLQ-HN35 in an Asian tertiary centre.

BACKGROUND: The objective of the study was to evaluate the quality of life (QOL) of head and neck cancer survivors after surgical treatment and to identify patients' main concerns. The study also aims to establish pre-treatment reference values particularly for the Asian patient. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) and Head and Neck module (EORTC QLQ-HN35) were used for objective evaluation. METHODS: Patients planned for elective surgery for head and neck cancers were enrolled in the study. The questionnaires were completed at pre-treatment and at 6 months after surgery. Results were compared with previously published reference values. RESULTS: One hundred forty patients completed both questionnaires. Locally advanced tumour and extent of surgery (tracheostomy (p<0.01), surgical flap (p<0.01)) were associated with lower global health scores. Adjuvant treatment was also a contributory factor (p<0.01). Dysphagia and social eating was a primary concern within our population. CONCLUSION: Surgical treatment of head and neck cancers is safe, but there is poor QOL in the early post-treatment period especially with eating. Previously published data suggested improvement after a year.

The mutational landscape of early- and typical-onset oral tongue squamous cell carcinoma.

BACKGROUND: The incidence of oral tongue squamous cell carcinoma (OTSCC) is increasing among younger birth cohorts. The etiology of early-onset OTSCC (diagnosed before the age of 50 years) and cancer driver genes remain largely unknown. METHODS: The Sequencing Consortium of Oral Tongue Cancer was established through the pooling of somatic mutation data of oral tongue cancer specimens (n = 227 [107 early-onset cases]) from 7 studies and The Cancer Genome Atlas. Somatic mutations at microsatellite loci and Catalog of Somatic Mutations in Cancer mutation signatures were identified. Cancer driver genes were identified with the MutSigCV and WITER algorithms. Mutation comparisons between early- and typical-onset OTSCC were evaluated via linear regression with adjustments for patient-related factors. RESULTS: Two novel driver genes (ATXN1 and CDC42EP1) and 5 previously reported driver genes (TP53, CDKN2A, CASP8, NOTCH1, and FAT1) were identified. Six recurrent mutations were identified, with 4 occurring in TP53. Early-onset OTSCC had significantly fewer nonsilent mutations even after adjustments for tobacco use. No associations of microsatellite locus mutations and mutation signatures with the age of OTSCC onset were observed. CONCLUSIONS: This international, multicenter consortium is the largest study to characterize the somatic mutational landscape of OTSCC and the first to suggest differences by age of onset. This study validates multiple previously identified OTSCC driver genes and proposes 2 novel cancer driver genes. In analyses by age, early-onset OTSCC had a significantly smaller somatic mutational burden that was not explained by differences in tobacco use. LAY SUMMARY: This study identifies 7 specific areas in the human genetic code that could be responsible for promoting the development of tongue cancer. Tongue cancer in young patients (under the age of 50 years) has fewer overall changes to the genetic code in comparison with tongue cancer in older patients, but the authors do not think that this is due to differences in smoking rates between the 2 groups. The cause of increasing cases of tongue cancer in young patients remains unclear.

Recommendations for head and neck surgical oncology practice in a setting of acute severe resource constraint during the COVID-19 pandemic: an international consensus.

The speed and scale of the global COVID-19 pandemic has resulted in unprecedented pressures on health services worldwide, requiring new methods of service delivery during the health crisis. In the setting of severe resource constraint and high risk of infection to patients and clinicians, there is an urgent need to identify consensus statements on head and neck surgical oncology practice. We completed a modified Delphi consensus process of three rounds with 40 international experts in head and neck cancer surgical, radiation, and medical oncology, representing 35 international professional societies and national clinical trial groups. Endorsed by 39 societies and professional bodies, these consensus practice recommendations aim to decrease inconsistency of practice, reduce uncertainty in care, and provide reassurance for clinicians worldwide for head and neck surgical oncology in the context of the COVID-19 pandemic and in the setting of acute severe resource constraint and high risk of infection to patients and staff.

Circulating extracellular vesicle-associated TGFß3 modulates response to cytotoxic therapy in head and neck squamous cell carcinoma.

Management of locally advanced head and neck squamous cell carcinoma (HNSCC) requires a multi-prong approach comprising surgery, radiation and/or chemotherapy, yet outcomes are limited. This is largely due to a paucity of biomarkers that can predict response to specific treatment modalities. Here, we evaluated TGFß3 protein levels in extracellular vesicles (EVs) released by HNSCC cells as a predictor for response to chemoradiation therapy (CRT). To this end, specific EV-fractions were isolated from cell lines or HNSCC patient plasma, and TGFß3 protein was quantified. In patients treated with CRT, TGFß3 levels were found to be significantly higher in plasma EV-fractions or non-responders compared with responders. High levels of TGFß3 levels in Annexin V-EVs were associated with the worst progression-free survival. In vitro experiments demonstrated that TGFß3 silencing sensitized HNSCC cells to cytotoxic therapies, and this phenotype could be rescued by treatment with exogenous. In addition, specific EV-fractions shed by cisplatin-resistant cells were sufficient to transfer the resistant phenotype to sensitive cells through activation of TGFß-signaling pathway. Therefore, our data show that TGFß3 transmitted through EV plays a significant role in response to cytotoxic therapy, which can be exploited as a potential biomarker for CRT response in HNSCC patients treated with curative intent.

Comparing the Utility and Surgical Outcomes of Harmonic Focus Ultrasonic Scalpel with Ligasure Small Jaw Bipolar Device in Thyroidectomies: A Prospective Randomized Controlled Trial.

BACKGROUND: Ultrasonic or bipolar radiofrequency energy devices are routinely used for dissection and hemostasis during thyroidectomy. We report a single-center, prospective, randomized controlled trial comparing the utility and outcomes of Harmonic Focus, an ultrasonic coagulating shear device (UCSD), versus Ligasure Small Jaw, an electrothermal bipolar vessel sealer (EBVS) in thyroidectomy (NCT01765686). METHODS: Between December 2012 to January 2016, eligible patients were randomized to undergo hemithyroidectomy using either a UCSD or an EBVS. The primary outcome was duration of surgery. Secondary outcomes included blood loss, postoperative complications, ease of device use, ease of device set-up, vocal cord function, postoperative wound drainage, pain score, and adverse events. RESULTS: Of 110 patients assessed for eligibility, 100 were randomly allocated (UCSD: 49 patients; EBVS: 51 patients) and analyzed by intention-to-treat. There were no differences in specimen delivery time, total duration of surgery, wound drainage, and adverse events between the two groups. The UCSD group had a greater proportion of patients with higher postoperative pain scores in the first 72 h (8.1% vs. 2.0%, p = 0.043). Surgeons reported greater ease of use for the UCSD (49% vs. 27%; p = 0.005), while operating room staff favored the EBVS (60% vs. 33%, p = 0.005). CONCLUSIONS: Energy devices are equally effective in reducing thyroidectomy operative times, with no differences in the duration of surgery, drainage, or adverse events. Use of the UCSD was associated with higher postoperative pain scores, but was favored by the surgeons, likely due to the ability to perform fine dissection with the device itself.

A preliminary investigation of circulating extracellular vesicles and biomarker discovery associated with treatment response in head and neck squamous cell carcinoma.

BACKGROUND: There is a paucity of plasma-based biomarkers that prospectively segregate the outcome of patients with head and neck squamous-cell carcinoma (HNSCC) treated with chemoradiation therapy (CRT). Plasma extracellular vesicles (EVs) might be an alternative source for discovery of new specific markers present in patients with HNSCC, which could help to re-direct patients to appropriate curative therapies without delay. METHODS: In order to identify new markers in plasma compartments, Cholerae toxin B chain (CTB) and Annexin V (AV) were used to isolate EVs from pooled plasma samples from patients with locally advanced HNSCC who responded (CR, n = 6) or presented incomplete response (NR, n = 6) to CRT. The crude plasma and EVs cargo were screened by antibody array. RESULTS: Of the 370 polypeptides detected, 119 proteins were specific to NR patients while 38 were exclusive of the CR subjects. The Gene Set Enrichment Analysis (GSEA) and Search Tool for the Retrieval of Interacting Genes (STRING) database analysis indicated that the content of circulating plasma EVs might have a relevant function for the tumor intercellular communication in the HNSCC patients. CONCLUSION: This study provides a list of potential markers present in plasma compartments that might contribute to the development of tools for prediction and assessment of CRT response and potentially guide therapeutic decisions in this context.

Analysis of clinically relevant somatic mutations in high-risk head and neck cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma is the second most prevalent malignancy, most frequently occurring in the head and neck (head and neck cutaneous squamous cell carcinoma). Treatment of locally advanced or metastatic disease is associated with functional morbidity and disfigurement. Underlying genetic mechanisms are poorly understood. Targeted sequencing of 48 clinically relevant genes was performed on DNA extracted from formalin-fixed and paraffin-embedded high-risk primary head and neck cutaneous squamous cell carcinomas that remained non-metastatic at minimum follow-up of 24 months. Associations of somatic mutations with clinicopathologic characteristics were evaluated and compared with those described in the literature for metastatic disease. Alterations in 44 cancer-associated genes were identified. TP53 was mutated in 100% of cases; APC, ATM, ERBB4, GNAQ, KIT, RB1 and ABL1 were altered in 60% of cases. FGFR2 mutations (40%) were exclusively seen in patients with perineural invasion. MLH1 mutations were exclusively seen in the two younger patients (<45 years). Lower incidences of NOTCH1 mutations were observed compared with that described in metastatic head and neck cutaneous squamous cell carcinoma in the literature. Somatic mutations susceptible to EGFR inhibitors, and other small molecular targeted therapeutics were seen in 60% of cases. This study provides insights into somatic mutations in non-metastatic, high-risk head and neck cutaneous squamous cell carcinoma and identifies potential therapeutic targets. Alterations in FGFR2 and NOTCH1 may have roles in local and distant disease progression.

Predictive value of the 8th edition American Joint Commission Cancer (AJCC) nodal staging system for patients with cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: The 8th edition American Joint Committee on Cancer (AJCC8) provides the same nodal staging system for mucosal and cutaneous squamous cell carcinoma of the head and neck (HNcSCC) and includes extranodal extension (ENE) as an adverse prognostic criterion. This study evaluates the prognostic efficacy of the AJCC8 pathologic nodal staging system (pN) for HNcSCC. METHODS: Univariate analysis of 382 patients with metastatic HNcSCC staged according to both the 7th (AJCC7) and the 8th edition staging systems. RESULTS: The AJCC7 pN3 category was associated with reduced disease specific survival (DSS HR 5.49; 95% CI: 1.83-16.53; P = 0.002) and overall survival (OS HR 3.42; 95% CI: 1.54-7.58; P = 0.002) as compared with pN1. However, no difference was observed between pN1, pN2, and pN3 categories as defined by the AJCC8. Also, when comparing Stages III and IV as defined by AJCC8, there was no difference in DSS (HR 0.75; 95% CI: 0.34-1.67; P = 0.478) or OS (HR 0.88; 95% CI: 0.51-1.51; P = 0.648). CONCLUSION: The AJCC8 performed poorly as a prognostic indicator for patients with metastatic HNcSCC in this cohort. HNcSCC would benefit from a staging system that accounts for its unique biologic characteristics distinct from mucosal SCC.

Survival of patients with head and neck squamous cell carcinoma by housing subsidy in a tiered public housing system.

BACKGROUND: Socioeconomic status affects survival in patients diagnosed with head and neck squamous cell carcinoma (HNSCC), even in health systems with universal health care. Singapore has a tiered subsidized housing system, in which income determines eligibility for subsidies by size of apartment. The objective of this study was to assess whether a patient's residential type (small/heavily subsidized, medium/moderate subsidy, large/minimal or no subsidy) influenced mortality. A secondary analysis examined whether patients in smaller subsidized apartments were more likely to present with advanced disease. METHODS: An historical cohort study of patients in a tertiary referral center with HNSCC was identified in the multidisciplinary cancer database from 1992 to 2014. Clinicopathologic data were extracted for analysis. Patient residential postal codes were matched to type of housing. Logistic regression was performed to evaluate the relationship between all-cause mortality and the predictors of interest as well as the association between housing type and disease stage at presentation. RESULTS: Of the 758 patients identified, most were men (73.4%), the median age was 64 years, 30.5% and 15.2% were smokers and former smokers, respectively. Over one-half (56.8%) of patients presented with advanced disease. Male gender, age, stage at presentation, survival time from diagnosis, and smoker status were significant predictors of mortality. Patients living in the smaller, higher subsidy apartments had poorer survival, although they were not more likely to present with advanced disease, suggesting that the survival difference was not because of delayed presentation. CONCLUSIONS: Patients with HNSCC living in smaller, higher-subsidy apartments have poorer survival despite no apparent delays in presentation. Cancer 2017;123:1998-2005. © 2017 American Cancer Society.

Nasopharyngectomy with operating microscope: A case series.

BACKGROUND: Nasopharyngectomy for excision of nasopharyngeal tumors is challenging, as access to the nasopharynx is difficult. Recently our institution embarked on two new approaches - robotic nasopharyngectomy and open nasopharyngectomy with operating microscope (NOM) via maxillary swing approach. This article proposes that the novel approach of NOM via maxillary swing aids visualization for resection of locally invasive nasopharyngeal tumors. METHODS: Over a thirteen-month period, eight patients required nasopharyngectomy in our single Asian institution. Four underwent robotic nasopharyngectomy and four underwent NOM via maxillary swing approach. The latter four were retrospectively reviewed, and their clinical characteristics and surgical outcomes reported. Tips and pearls for operative setup and patient selection were also discussed. RESULTS: All four patients who underwent NOM had negative intraoperative frozen sections with subsequent negative paraffin sections. All patients remained disease free post-salvage surgery. CONCLUSION: NOM via maxillary swing allows better visualization and aids in augmentation of open nasopharyngectomy. This enables achievement of adequate resection margins and fewer surgical complications in locally invasive nasopharyngeal tumors.

Distant metastasis as the sole initial manifestation of well-differentiated thyroid carcinoma.

Thyroid carcinoma usually presents as a neck lump. Distant metastasis as the sole initial manifestation of well-differentiated thyroid carcinoma (WDTC) is rare and little is known about these patients. The aim of this study is to characterize patients who present with distant metastasis as the sole initial manifestation of WDTC. Retrospective review of case records of WDTC seen at the National Cancer Centre Singapore from 2002 to 2015 was performed. Patients with no prior complaint of neck swelling and whose first presentation was distant metastatic WDTC were included. Patient demographics, disease characteristics, radiological imaging, histopathology, types of treatment administered, and survival outcomes were examined. Nineteen out of seven hundred and thirty-two cases fulfilled inclusion criteria. Mean age was 65.4 years. All patients presented with osseous (36.8%), pulmonary (31.6%), cerebral metastases (5.3%), or a combination of two out of three aforementioned sites (26.3%). Follicular thyroid carcinoma was most common (47.4%), followed by papillary (36.8%) and medullary (15.8%). More than two-thirds of patients had multiple metastatic foci. Thirteen out of nineteen patients (68.4%) underwent total thyroidectomy with or without neck dissection and adjuvant RAI, while the rest declined surgery. The mean length of follow-up was 40.1 ± 5.1 months and 5-year disease-specific survival was 48.0 ± 17.2%. Distant metastasis without a history of neck swelling as the initial presentation of WDTC is extremely rare. Osseous metastasis and follicular thyroid carcinoma are the most common metastatic site and etiology, respectively. Disease-specific survival at 5-year post-diagnosis is lower compared to patients with thyroid carcinoma diagnosed with distant metastasis on further work-up.

Novel therapeutic targets on the horizon for lung cancer.

Lung cancer is a leading cause of cancer-related mortality worldwide, and is classically divided into two major histological subtypes: non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Although NSCLC and SCLC are considered distinct entities with different genomic landscapes, emerging evidence highlights a convergence in therapeutically relevant targets for both histologies. In adenocarcinomas with defined alterations such as EGFR mutations and ALK translocations, targeted therapies are now first-line standard of care. By contrast, many experimental and targeted agents remain largely unsuccessful for SCLC. Intense preclinical research and clinical trials are underway to exploit unique traits of lung cancer, such as oncogene dependency, DNA damage response, angiogenesis, and cellular plasticity arising from presence of cancer stem cell lineages. In addition, the promising clinical activity observed in NSCLC in response to immune checkpoint blockade has spurred great interest in the field of immunooncology, with the scope to develop a diverse repertoire of synergistic and personalised immunotherapeutics. In this Review, we discuss novel therapeutic agents for lung cancer that are in early-stage development, and how prospective clinical trials and drug development may be shaped by a deeper understanding of this heterogeneous disease.

Randomized trial comparing surgery and adjuvant radiotherapy versus concurrent chemoradiotherapy in patients with advanced, nonmetastatic squamous cell carcinoma of the head and neck: 10-year update and subset analysis.

BACKGROUND: The current study was performed to report the long-term results of a trial comparing concurrent chemotherapy and radiotherapy (CCRT) with surgery and adjuvant radiotherapy (RT) in patients with stage III/IV nonmetastatic head and neck squamous cell carcinoma. METHODS: Patients with stage III/IV resectable head and neck squamous cell carcinoma were randomized to surgery followed by RT or CCRT. The trial was halted prematurely due to poor accrual. Human papillomavirus status was tested on archival material using polymerase chain reaction sequencing. RESULTS: Of the total of 119 patients, 60 patients were randomized to primary surgery (S arm) and 59 patients were randomized to CCRT (C arm). Human papillomavirus status was tested in 75 patients, and only 3 were found to be positive. The median follow-up for surviving patients was 13 years. Analysis of the entire cohort demonstrated no statistically significant difference in overall survival and disease-specific survival (DSS): 5-year rates were 45% versus 35% for overall survival (P = .262) and 56% versus 46% for DSS (P = .637) for the S arm and C arm, respectively. Analysis by subsites indicated that this difference favoring the S arm was mainly driven by survival data among patients with cancers of the oral cavity and maxillary sinus. For patients with oral cavity cancer, survival was significantly better in those who underwent primary surgery compared with CCRT; the 5-year DSS rate was 68% versus 12% for the S arm and C arm, respectively (P = .038). For patients with cancers of the maxillary sinus, the 5-year DSS rate was 71% for patients on the S arm and 0% for patients on the C arm (P = .05). CONCLUSIONS: These long-term results demonstrate a significant advantage for primary surgery in patients with cancers of the oral cavity or maxillary sinus, providing strong support for primary surgery as the main modality of treatment for these subsites. In other subsites, CCRT and surgery with adjuvant RT were found to demonstrate similar efficacy for survival in patients with advanced resectable tumors.

Detailed Analysis of Clinicopathologic Factors Demonstrate Distinct Difference in Outcome and Prognostic Factors Between Surgically Treated HPV-Positive and Negative Oropharyngeal Cancer.

BACKGROUND: Oropharyngeal cancers (OPC) secondary to human papillomavirus (HPV) infections likely represent a completely different disease compared with conventional head and neck cancers. Our objective was to analyze a surgically treated cohort to determine predictors of outcome in HPV-positive versus HPV-negative patients. METHODS: HPV positivity was inferred based on p16-immunohistochemistry. Data was available for 201 patients with OPC treated with surgical resection with/without adjuvant radiotherapy between 1985 and 2005. Subsite distribution was: 66 (33 %) tonsil, 46 (23 %) soft palate, and 89 (44 %) tongue base. Patients were classified into low-, intermediate-, and high-risk groups based on p16 status and smoking history. Outcomes stratified by p16 status and risk groups were determined by the Kaplan-Meier method. Factors predictive of outcome were determined by univariate and multivariate analyses. RESULTS: In this cohort, 30 % had locally advanced disease (pT3/T4) and 71 % had nodal metastasis. The 5-year overall (OS), disease-specific, and recurrence-free survival rates were 60, 76, and 66 %, respectively. There were 22 % low-, 34 % intermediate-, and 44 % high-risk patients. Patients who were p16-positive had better survival compared with p16-negative (OS, 74 vs. 44 %; p < .001). Similarly, low-risk group patients had a better survival compared with intermediate- and high-risk groups (OS, 76, 68, 45 %, respectively, p < .001). Independent predictors of survival in p16-negative patients included margin status, lymphovascular invasion, pN status, and extracapsular spread. In contrast, none of these were predictive in p16-positive patients. CONCLUSIONS: Surgically treated patients with p16-positive OPC have superior survival compared with p16-negative patients. Outcomes in p16-positive and p16-negative OPC are determined by different prognostic factors supporting the notion that these are very different diseases. These should be incorporated into future clinical trials design.

Microarray profiling shows distinct differences between primary tumors and commonly used preclinical models in hepatocellular carcinoma.

BACKGROUND: Despite advances in therapeutics, outcomes for hepatocellular carcinoma (HCC) remain poor and there is an urgent need for efficacious systemic therapy. Unfortunately, drugs that are successful in preclinical studies often fail in the clinical setting, and we hypothesize that this is due to functional differences between primary tumors and commonly used preclinical models. In this study, we attempt to answer this question by comparing tumor morphology and gene expression profiles between primary tumors, xenografts and HCC cell lines. METHODS: Hep G2 cell lines and tumor cells from patient tumor explants were subcutaneously (ectopically) injected into the flank and orthotopically into liver parenchyma of Mus Musculus SCID mice. The mice were euthanized after two weeks. RNA was extracted from the tumors, and gene expression profiling was performed using the Gene Chip Human Genome U133 Plus 2.0. Principal component analyses (PCA) and construction of dendrograms were conducted using Partek genomics suite. RESULTS: PCA showed that the commonly used HepG2 cell line model and its xenograft counterparts were vastly different from all fresh primary tumors. Expression profiles of primary tumors were also significantly divergent from their counterpart patient-derived xenograft (PDX) models, regardless of the site of implantation. Xenografts from the same primary tumors were more likely to cluster together regardless of site of implantation, although heat maps showed distinct differences in gene expression profiles between orthotopic and ectopic models. CONCLUSIONS: The data presented here challenges the utility of routinely used preclinical models. Models using HepG2 were vastly different from primary tumors and PDXs, suggesting that this is not clinically representative. Surprisingly, site of implantation (orthotopic versus ectopic) resulted in limited impact on gene expression profiles, and in both scenarios xenografts differed significantly from the original primary tumors, challenging the long-held notion that orthotopic PDX model is the gold standard preclinical model for HCC.

The extracellular matrix protein TGFBI induces microtubule stabilization and sensitizes ovarian cancers to paclitaxel.

The extracellular matrix (ECM) can induce chemotherapy resistance via AKT-mediated inhibition of apoptosis. Here, we show that loss of the ECM protein TGFBI (transforming growth factor beta induced) is sufficient to induce specific resistance to paclitaxel and mitotic spindle abnormalities in ovarian cancer cells. Paclitaxel-resistant cells treated with recombinant TGFBI protein show integrin-dependent restoration of paclitaxel sensitivity via FAK- and Rho-dependent stabilization of microtubules. Immunohistochemical staining for TGFBI in paclitaxel-treated ovarian cancers from a prospective clinical trial showed that morphological changes of paclitaxel-induced cytotoxicity were restricted to areas of strong expression of TGFBI. These data show that ECM can mediate taxane sensitivity by modulating microtubule stability.

Intertumor heterogeneity of non-small-cell lung carcinomas revealed by multiplexed mutation profiling and integrative genomics.

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease, with a burden of genomic alterations exceeding most other tumors. The goal of our study was to evaluate the frequencies of co-occurring mutations and copy-number aberrations (CNAs) within the same tumor and to evaluate their potential clinical impact. Mass-spectrometry based mutation profiling using a customized lung cancer panel evaluating 214 mutations across 26 key NSCLC genes was performed on 230 nonsquamous NSCLC and integrated with genome-wide CNAs and clinical variables. Among the 138 cases having at least one mutation, one-third (41, 29.7%) showed two or more mutations, either in the same gene (double mutation) or in different genes (co-mutations). In epidermal growth factor receptor (EGFR) mutant cancers, there was a double mutation in 18% and co-mutations in the following genes: TP53 (10%), PIK3CA (8%), STK11 (6%) and MET (4%). Significant relationships were detected between EGFR mutation and 1p, 7p copy gains (harboring the EGFR gene) as well as 13q copy loss. KRAS mutation was significantly related with 1q gain and 3q loss. For Stage I, tumors harboring at least one mutation or PIK3CA mutation were significantly correlated with poor prognosis (p-value = 0.02). When combining CNAs and mutational status, patients having both KRAS mutation and the highest related CNA (3q22.3 copy loss) showed a significant poorer prognosis (p-value = 0.03). Our study highlights the clinical relevance of studying tumor complexity by integrative genomic analysis and the need for developing assays that broadly screen for both "actionable" mutations and copy-number alterations to improve precision of stratified treatment approaches.