RET Alterations Differentiate Molecular Profile of Medullary Thyroid Cancer.

PURPOSE: Medullary thyroid cancer (MTC) is a rare cancer originating from parafollicular C cells of the thyroid gland. Therapeutically relevant alterations in MTC are predominantly reported in RET oncogene, and lower-frequency alterations are reported in KRAS and BRAF. Nevertheless, there is an unmet need existing to analyze the MTC in the Indian cohort by using in-depth sequencing techniques that go beyond the identification of known therapeutic biomarkers. MATERIALS AND METHODS: Here, we characterize MTC using integrative whole-exome and whole-transcriptome sequencing of 32 MTC tissue samples. We performed clinically relevant variant analysis, molecular pathway analysis, tumor immune-microenvironment analysis, and structural characterization of RET novel mutation. RESULTS: Mutational landscape analysis shows expected RET mutations in 50% of the cases. Furthermore, we observed mutations in known cancer genes like KRAS, HRAS, SF3B1, and BRAF to be altered only in the RET-negative cohort. Pathway analysis showed differential enrichment of mutations in transcriptional deregulation genes in the RET-negative cohort. Furthermore, we observed novel RET kinase domain mutation Y900S showing affinity to RET inhibitors accessed via molecular docking and molecular dynamics simulation. CONCLUSION: Altogether, this study provides a detailed genomic characterization of patients with MTC of Indian origin, highlighting the possible utility of targeted therapies in this disease.

Clinical characteristics, outcomes and prognostic factors in KRAS mutant lung cancers: experience from a tertiary care cancer center in India.

Objectives: Kirsten rat sarcoma viral oncogene homologue (KRAS) mutations in lung cancers, long considered untargetable, have had a recent rise in interest due to promising data of agents targeting KRAS p.G12C. As Indian data are scarce, we sought to identify baseline clinical characteristics, prognostic factors and outcomes of lung cancer patients with KRAS mutations at our hospital. Methods: Patients with KRAS mutant lung cancers treated at our institute from 2016 to 2022 were analysed. Results: 133 patients with KRAS mutant lung cancers were identified. Median age was 57 (interquartile range 28-78) years, and 58 (43.6%) were smokers. 17 (12.7%) had brain metastases. The commonest variant was p.G12C, seen in 53 (39.8%) patients. Six (4.5%) had programmed death ligand 1 (PDL-1) expression >50% by Ventana SP263 PDL-1 assay, and 13 (9.7%) had epidermal growth factor mutation. Of 92 patients with available treatment details, the majority received intravenous chemotherapy, nine (9.8%) received tyrosine kinase inhibitors and four (4.4%) received immunotherapy (pembrolizumab). Median progression-free survival (PFS) with first-line therapy was 6 (95% confidence interval (CI) 2.8-9.2) months and median overall survival (OS) was 12 (CI 9.2-14.8) months. The incidence of brain metastases was higher in patients with G12C mutations (p = 0.025). Brain metastases (HR: 3.57, p < 0.001), Eastern Cooperative Oncology Group performance status (PS) ≥ 2 (HR: 2.13, p = 0.002) and G12C mutation (HR: 1.84, p = 0.011) were associated with inferior PFS, while brain metastases (HR: 4.6, p < 0.001), PS ≥ 2 (HR: 2.33, p = 0.001) and G12C mutation (HR: 1.93, p = 0.01) were associated with inferior OS. Conclusion: This is the largest dataset of KRAS mutant lung cancers from India. Brain metastases were higher in patients with G12C mutations and associated with poorer PFS and OS. G12C mutation and PS ≥ 2 were also associated with inferior PFS and OS. Experience with targeted therapy for KRAS mutations remains an area of future exploration due to the unavailability of these agents in India.

Natural History of Germline BRCA1 Mutated and BRCA Wild-type Triple-negative Breast Cancer.

We report a deep next-generation sequencing analysis of 13 sequentially obtained tumor samples, eight sequentially obtained circulating tumor DNA (ctDNA) samples and three germline DNA samples over the life history of 3 patients with triple-negative breast cancer (TNBC), 2 of whom had germline pathogenic BRCA1 mutation, to unravel tumor evolution. Tumor tissue from all timepoints and germline DNA was subjected to whole-exome sequencing (WES), custom amplicon deep sequencing (30,000X) of a WES-derived somatic mutation panel, and SNP arrays for copy-number variation (CNV), while whole transcriptome sequencing (RNA-seq) was performed only on somatic tumor.There was enrichment of homologous recombination deficiency signature in all tumors and widespread CNV, which remained largely stable over time. Somatic tumor mutation numbers varied between patients and within each patient (range: 70-216, one outlier). There was minimal mutational overlap between patients with TP53 being the sole commonly mutated gene, but there was substantial overlap in sequential samples in each patient. Each patient's tumor contained a founding ("stem") clone at diagnosis, which persisted over time, from which all other clones ("subclone") were derived ("branching evolution"), which contained mutations in well-characterized cancer-related genes like PDGFRB, ARID2, TP53 (Patient_02), TP53, BRAF, BRIP1, CSF3R (Patient_04), and TP53, APC, EZH2 (Patient_07). Including stem and subclones, tumors from all patients were polyclonal at diagnosis and during disease progression. ctDNA recapitulated most tissue-derived stem clonal and subclonal mutations while detecting some additional subclonal mutations. RNA-seq revealed a stable basal-like pattern, with most highly expressed variants belonging to stem clone. SIGNIFICANCE: In germline BRCA1 mutated and BRCA wild-type patients, TNBC shows a branching evolutionary pattern of mutations with a single founding clone, are polyclonal throughout their disease course, and have widespread copy-number aberrations. This evolutionary pattern may be associated with treatment resistance or sensitivity and could be therapeutically exploited.

Whole exome sequencing uncovers HRAS mutations as potential mediators of resistance to metronomic chemotherapy.

OBJECTIVES: The aim of this pilot study is to identify the genetic factors that contribute to the response of metronomic chemotherapy in head and neck squamous cell carcinoma (HNSCC) patients using whole-exome sequencing (WES). This study would facilitate the identification of predictive biomarkers, which would enable personalized treatment strategies and improve treatment outcomes for patients with HNSCC. MATERIALS AND METHODS: We have selected patients with recurrent head and neck cancer who underwent metronomic chemotherapy. Sequential tumor biopsies were collected from the patients at different stages of treatment to capture the genomic alterations and tumor evolution during metronomic chemotherapy and sequenced using WES. RESULTS: We identified several known HNSCC hallmark genes reported in COSMIC, including KMT2B, NOTCH1, FAT1, TP53, HRAS, CASP8, and CDKN2A. Copy number alteration analysis revealed amplifications and deletions in several oncogenic and tumor suppressor genes. COSMIC Mutational Signature 15 associated with defective DNA mismatch repair was enriched in 73% of HNSCC samples. Further, the comparison of genomic alterations between responders and non-responders identified HRAS gene uniquely mutated in non-responders that could potentially contribute to resistance against metronomic chemotherapy. DISCUSSION: Our findings corroborate the molecular heterogeneity of recurrent HNSCC tumors and establish an association between HRAS mutations and resistance to metronomic chemotherapy, suggesting HRAS as a potential therapeutic target. Combining HRAS inhibitors with metronomic regimens could improve treatment sensitivity in HRAS-mutated HNSCC patients. Further studies are needed to fully elucidate the genomic mechanisms underlying the response to metronomic chemotherapy.

Understanding the Impact of Population and Cancer Type on Tumor Mutation Burden Scores: A Comprehensive Whole-Exome Study in Cancer Patients From India.

PURPOSE: The purpose of this study was to understand the impact of population diversity and geographic variation on tumor mutation burden (TMB) scores across cancers and its implication on stratification of patients for immune checkpoint inhibitor (ICI) therapy. MATERIALS AND METHODS: This retrospective study used whole-exome sequencing (WES) to profile 1,233 Indian patients with cancer across 30 different cancer types and to estimate their TMB scores. A WES-based pipeline was adopted, along with an indigenously developed strategy for arriving at true somatic mutations. A robust unsupervised machine learning approach was used to understand the distribution of TMB scores across different populations and within the population. RESULTS: The results of the study showed a biphasic distribution of TMB scores in most cancers, with different threshold scores across cancer types. Patients with cancer in India had higher TMB scores compared with the Caucasian patients. We also observed that the TMB score value at 90th percentile (predicting high efficacy to ICI) was high in four different cancer types (sarcoma, ovary, head and neck, and breast) in the Indian cohort as compared with The Cancer Genome Atlas or public cohort. However, in lung and colorectal cancers, the TMB score distribution was similar between the two population cohorts. CONCLUSION: The findings of this study indicate that it is crucial to benchmark both cancer-specific and population-specific TMB distributions to establish a TMB threshold for each cancer in various populations. Additional prospective studies on much larger population across different cancers are warranted to validate this observation to become the standard of care.

Real-World Evidence of EGFR Targeted Therapy in NSCLC- A Brief Report of Decade Long Single Center Experience.

The significance of EGFR targeted therapy in the lung adenocarcinoma is paramount. Several controlled clinical trials have reported considerable survival of EGFR mutation positive patients on receiving the EGFR tyrosine kinase inhibitor (TKI). However, the real-world evidence of benefits of EGFR TKI would be further useful to understand how the designated therapeutic regimen benefits the patients. In this study, we report a decade long real-world evidence of EGFR molecular testing in lung cancer at Tata Memorial Hospital (Mumbai, India). Laboratory and hospital records containing basic demographic details, clinical characteristics, treatment regimen, survival outcome were collected retrospectively. Statistical association and survival analysis were performed using the R programming. The cohort includes 9,053 lung cancer patients tested for EGFR mutations during 2011 to 2019. Baseline T790M and compound mutations were the only mutations observed co-occurring while all other EGFR mutations were mutually exclusive. Furthermore, the baseline T790M were also observed to be associated with TTF1 positivity, smoking and local metastasis. Overall survival of the patients harboring co-occurring compound mutations was significantly lesser than the other EGFR positive patients. Overall, our study suggests that EGFR TKI may provide real-world benefit to the lung cancer patients harboring mutually exclusive EGFR mutations. On the other hand, further systematic study is essential to develop better therapeutic regimen for co-occurring baseline EGFR T790M and other compound mutations.

Association of Cutibacterium acnes with human thyroid cancer.

Introduction: The diverse subtypes of thyroid carcinoma have distinct clinical outcomes despite a comparable spectrum of underlying genetic alterations. Beyond genetic alterations, sparse efforts have been made to characterize the microbes associated with thyroid cancer. In this study, we examine the microbial profile of thyroid cancer. Methods: We sequenced the whole transcriptome of 70 thyroid cancers (40 papillary and 30 anaplastic). Using Infectious Pathogen Detector IPD 2.0, we analysed the relative abundance of 1060 microbes across 70 tumours from patients with thyroid cancer against 118 tumour samples from patients with breast, cervical, colorectal, and tongue cancer. Results: Our analysis reveals a significant prevalence of Cutibacterium acnes in 58.6% thyroid cancer samples compared to other cancer types (p=0.00038). Immune cell fraction analysis between thyroid cancer samples with high and low Cutibacterium loads identify enrichment of immunosuppressive cells, including Tregs (p=0.015), and other anti-inflammatory cytokines in the tumour microenvironment, suggesting an immune evasion/immunosuppression milieu is associated with the infection. A higher burden of Cutibacterium acnes was also found to be associated with poor survival defining a distinct sub-group of thyroid cancer. Conclusion: Cutibacterium acnes is associated with immune suppression and poor prognosis in a subpopulation of thyroid cancer. This study may help design novel therapeutic measures involving appropriate antibiotics to manage the disease better.

In silico structural analysis of secretory clusterin to assess pathogenicity of mutations identified in the evolutionarily conserved regions.

Clusterin (CLU) is a secreted glycoprotein, heterodimeric in nature, and is expressed in a wide variety of tissues and body fluids such as serum and plasma. CLU has also been known to be a promising biomarker for cell death, malignancy, cancer progression, and resistance development. However, the lack of a CLU crystal structure obstructs understanding the possible role of reported mutations on the structure, and the subsequent effects on downstream signaling pathways and cancer progression. Considering the importance of crystal structure, a model structure of the pre-secretory isoform of CLU was built to predict the effect of mutations at the molecular level. Ab initio model was built using RaptorX, and loop refinement and energy minimization were carried out with ModLoop, ModRefiner, and GalaxyWeb servers. The cancer associated mutational spectra of CLU was retrieved from the cBioPortal server and 117 unique missense mutations were identified. Evolutionarily conserved regions and pathogenicity of mutations identified in CLU were analyzed using ConSurf and Rhapsody, respectively. Furthermore, sequence and structure-based mutational analysis were carried out with iSTABLE, DynaMut and PremPS servers. Molecular dynamics simulations were carried out with GROMACS for 50 ns to determine the stability of the wild type and mutant protein structures. A dynamically stable model structure of pre-secretory CLU (psCLU) which has high concurrence with the sequence based secondary structure predictions has been explored. Changes in the intra-atomic interactions and folding pattern between wild type and mutant structures were observed. To our conclusion, eleven mutations with the highest structural and functional significance have been predicted to have pathogenic and deleterious effects.Communicated by Ramaswamy H. Sarma.

Progesterone modulates the DSCAM-AS1/miR-130a/ESR1 axis to suppress cell invasion and migration in breast cancer.

BACKGROUND: A preoperative-progesterone intervention increases disease-free survival in patients with breast cancer, with an unknown underlying mechanism. We elucidated the role of non-coding RNAs in response to progesterone in human breast cancer. METHODS: Whole transcriptome sequencing dataset of 30 breast primary tumors (10 tumors exposed to hydroxyprogesterone and 20 tumors as control) were re-analyzed to identify differentially expressed non-coding RNAs followed by real-time PCR analyses to validate the expression of candidates. Functional analyses were performed by genetic knockdown, biochemical, and cell-based assays. RESULTS: We identified a significant downregulation in the expression of a long non-coding RNA, Down syndrome cell adhesion molecule antisense DSCAM-AS1, in response to progesterone treatment in breast cancer. The progesterone-induced expression of DSCAM-AS1 could be effectively blocked by the knockdown of progesterone receptor (PR) or treatment of cells with mifepristone (PR-antagonist). We further show that knockdown of DSCAM-AS1 mimics the effect of progesterone in impeding cell migration and invasion in PR-positive breast cancer cells, while its overexpression shows an opposite effect. Additionally, DSCAM-AS1 sponges the activity of miR-130a that regulates the expression of ESR1 by binding to its 3'-UTR to mediate the effect of progesterone in breast cancer cells. Consistent with our findings, TCGA analysis suggests that high levels of miR-130a correlate with a tendency toward better overall survival in patients with breast cancer. CONCLUSION: This study presents a mechanism involving the DSCAM-AS1/miR-130a/ESR1 genomic axis through which progesterone impedes breast cancer cell invasion and migration. The findings highlight the utility of progesterone treatment in impeding metastasis and improving survival outcomes in patients with breast cancer.

Integrated proteomics and phosphoproteomics revealed druggable kinases in neoadjuvant chemotherapy resistant tongue cancer.

Tongue squamous cell carcinoma is an aggressive oral cancer with a high incidence of metastasis and poor prognosis. Most of the oral cavity cancer patients present in clinics with locally advanced unresectable tumors. Neoadjuvant treatment is beneficial for these individuals as it reduces the tumor size aiding complete resection. However, patients develop therapy resistance to the drug regimen. In this study, we explored the differential expression of proteins and altered phosphorylation in the neoadjuvant chemotherapy resistant tongue cancer patients. We integrated the proteomic and phosphoproteomic profiles of resistant (n = 4) and sensitive cohorts (n = 4) and demonstrated the differential expression and phosphorylation of proteins in the primary tissue of the respective subject groups. We observed differential and extensive phosphorylation of keratins such as KRT10 and KRT1 between the two cohorts. Furthermore, our study revealed a kinase signature associated with neoadjuvant chemotherapy resistance. Kinases such as MAPK1, AKT1, and MAPK3 are predicted to regulate the resistance in non-responders. Pathway analysis showed enrichment of Rho GTPase signaling and hyperphosphosphorylation of proteins involved in cell motility, invasion, and drug resistance. Targeting the kinases could help with the clinical management of neoadjuvant chemotherapy-resistant tongue cancer.

In vivo tumor immune microenvironment phenotypes correlate with inflammation and vasculature to predict immunotherapy response.

Response to immunotherapies can be variable and unpredictable. Pathology-based phenotyping of tumors into 'hot' and 'cold' is static, relying solely on T-cell infiltration in single-time single-site biopsies, resulting in suboptimal treatment response prediction. Dynamic vascular events (tumor angiogenesis, leukocyte trafficking) within tumor immune microenvironment (TiME) also influence anti-tumor immunity and treatment response. Here, we report dynamic cellular-level TiME phenotyping in vivo that combines inflammation profiles with vascular features through non-invasive reflectance confocal microscopic imaging. In skin cancer patients, we demonstrate three main TiME phenotypes that correlate with gene and protein expression, and response to toll-like receptor agonist immune-therapy. Notably, phenotypes with high inflammation associate with immunostimulatory signatures and those with high vasculature with angiogenic and endothelial anergy signatures. Moreover, phenotypes with high inflammation and low vasculature demonstrate the best treatment response. This non-invasive in vivo phenotyping approach integrating dynamic vasculature with inflammation serves as a reliable predictor of response to topical immune-therapy in patients.

Treatment pattern and outcomes in de novo T790M-mutated non-small cell lung cancer.

Introduction: Limited data exists for non-small cell lung cancer (NSCLC) patients harbouring de novo T790M mutation. Methods: NSCLC patients, with de novo T790M, who registered at our institute between 01/03/2015 and 31/12/2019, were considered for retrospective analysis of treatment pattern and clinical outcomes, i.e., progression-free survival (PFS) and overall survival (OS). Results: Of 1,542 epidermal growth factor receptor (EGFR)-mutated patients, 40 (2.59%) had de novo T790M. Most were male (27, 67.5%) and smokers (23, 57.5%). The commonest site of metastasis was the lungs (31, 77.5%), while 7 (17.5%) had central nervous system (CNS) involvement. Additional EGFR gene mutations and anaplastic lymphoma kinase (ALK) positivity were observed in 20 (50.0%) and 4 (10.0%) cases, respectively. The first-line systemic therapy and the number of patients receiving it were as follows: osimertinib by 14 (35.0%), first-generation EGFR tyrosine kinase inhibitors (TKIs) by 10 (25.0%), gefitinib + chemotherapy by 3 (7.5%), chemotherapy by 7 (17.5%) and gefitinib + bevacizumab by 2 (5%). One patient defaulted before starting any treatment. Hence, 39 were considered for survival analysis. The median PFS and OS for the entire cohort were 10.4 (95% CI = 7.6-19.7) months and 24.9 (95% CI = 15.7-NA) months, respectively. The median PFS for patients on osimertinib was 19.8 (95% CI = 11.6-28.0) months versus 8.8 (95% CI = 6.6-10.9) months for those on other systemic therapy. No CNS involvement, use of osimertinib or first-generation EGFR TKI plus chemotherapy or ALK inhibitor in ALK-positive cases prognosticated better PFS. When compared to other systemic therapies, osimertinib improved PFS in patients with or without additional EGFR mutations, although it was statistically significant for the former group only (p = 0.002). Conclusion: The incidence of de novo T790M is low. Osimertinib in frontline therapy provides promising outcomes.

Impact of Molecular Tumor Board on the Clinical Management of Patients With Cancer.

PURPOSE: Multidisciplinary molecular tumor boards (MTBs) help in interpreting complex genomic data generated by molecular tumor profiling and improve patients' access to targeted therapies. The purpose of this study was to assess the impact of our institution's MTB on the clinical management of patients with cancer. METHODS: This study was conducted at a tertiary cancer center in India. Cases to be discussed in the MTB were identified by molecular pathologists, scientists, or oncologists. On the basis of the clinical data and molecular test reports, a course of clinical management was recommended and made available to the treating oncologist. We determined the proportion of patients who were recommended a change in the clinical management. We also assessed compliance of the treating oncologists with MTB recommendations. RESULTS: There were 339 discussions for 328 unique patients. The median age of the cohort was 54 years (range 17-87), and the majority of the patients were men (65.1%). Of 339 cases, 133 (39.2%) were recommended continuation of ongoing therapy while the remaining 206 (60.7%) were recommended a change in clinical management. Compliance with MTB recommendations for a change in clinical management was 58.5% (79 of 138 evaluable cases). Compliance and implementation for MTB's recommendation to start a new therapy in 104 evaluable cases were 60.5% and 44.2%, respectively. A total of 248 biopsies had at least one actionable mutation. A total of 646 mutations were identified in the cohort, with EGFR being the most frequently altered gene. CONCLUSION: MTBs help in interpreting results of molecular tests, understanding the significance of molecular abnormalities, and assessing the benefits of available targeted therapies and clinical trials in the management of patients with targetable genetic alterations.

Clinical Utility of Liquid Biopsy (Cell-free DNA) Based EGFR Mutation Detection Post treatment Initiation as a Disease Monitoring Tool in Patients With Advanced EGFR-mutant NSCLC.

INTRODUCTION: Plasma cfDNA-based mutation analysis has shown disease-monitoring potential in various cancers. We assessed the potential of cfDNA-based EGFR mutation testing as a monitoring tool in patients with NSCLC. PATIENTS AND METHODS: Patients with NSCLC harboring EGFR mutations receiving first-line treatment as per institutional protocol were enrolled. EGFR mutation status was determined using plasma samples at baseline and post treatment initiation. Patients in whom EGFR mutation was detected or persisted after treatment initiation were considered circulating tumor DNA (ctDNA)-positive. Progression-free survival (PFS) and overall survival (OS) for ctDNA-positive and negative patients post treatment initiation were the primary endpoints; concordance for baseline EGFR status between tissue and plasma and proportion of patients who were ctDNA-positive post treatment initiation were the secondary endpoints. RESULTS: We enrolled 158 patients; 76 received gefitinib, and 82 received gefitinib plus chemotherapy. Median follow-up duration was 42 months. About 25% of patients were ctDNA-positive post treatment initiation. Median PFS for ctDNA-negative patients post treatment initiation was 14 (95% confidence interval [CI], 12.0-17.0) months, while that for ctDNA-positive patients was 8 (95% CI, 6.0-10.0) months. Median OS for ctDNA-negative patients post treatment initiation was 27 (95% CI, 24.0-32.0) months, while that for ctDNA-positive patients was 15 (95% CI, 11.0-19.0) months. Concordance at baseline between tissue and plasma samples was 75.4%. CONCLUSION: Plasma-based EGFR mutation detection post treatment initiation can be used as a predictive marker for outcome in patients with EGFR-mutant NSCLC receiving first-line treatment.

Comprehensive Development and Implementation of Good Laboratory Practice for NGS Based Targeted Panel on Solid Tumor FFPE Tissues in Diagnostics.

The speed, accuracy, and increasing affordability of next-generation sequencing (NGS) have revolutionized the advent of precision medicine. To date, standardized validation criteria for diagnostic accreditation do not exist due to variability across the multitude of NGS platforms and within NGS processes. In molecular diagnostics, it is necessary to ensure that the primary material of the FFPE sample has good quality and optimum quantity for the analysis, otherwise the laborious and expensive NGS test may result in unreliable information. Therefore, stringent quality control of DNA and RNA before, during, and after library preparation is an essential parameter. Considering the various challenges with the FFPE samples, we aimed to set a benchmark in QC metrics that can be utilized by molecular diagnostic laboratories for successful library preparation and high-quality NGS data output. In total, 144 DNA and 103 RNA samples of various cancer types with a maximum storage of 2 years were processed for 52 gene focus panels. During the making of DNA and RNA libraries, extensive QC check parameters were imposed at different checkpoints. The decision tree approach can be set as a benchmark for FFPE samples and as a guide to establishing a good clinical laboratory practice for targeted NGS panels.

Systemic Therapy in Thyroid Cancer.

Thyroid cancer is the most common endocrine malignancy. While surgery remains the mainstay of the treatment of all different histologies, for differentiated thyroid cancers, radioactive iodine also plays an important role in management. Once tumor becomes radio-iodine refractory, it needs systemic therapy. Earlier, these tumors had very dismal prognosis. However, with the advancement of technology and research, it has become clear now that thyroid cancer cells are driven by various mutations. Targeting these oncogenic drivers by various molecules have proven to be effective therapeutic strategy in thyroid cancer. Besides, as in other solid tumors, immunotherapy is also being evaluated in thyroid cancer. While these new therapeutic approaches have revolutionized the treatment on advanced/metastatic thyroid cancer, there are definite challenges which limit their use in common clinical practice. These challenges include higher treatment cost and lack of testing to identify the driver mutations. Moreover, there is still need for further research in thyroid cancers to identify oncogenic targets and agent to act upon them.

Fusobacterium nucleatum is associated with inflammation and poor survival in early-stage HPV-negative tongue cancer.

Persistent pathogen infection is a known cause of malignancy, although with sparse systematic evaluation across tumor types. We present a comprehensive landscape of 1060 infectious pathogens across 239 whole exomes and 1168 transcriptomes of breast, lung, gallbladder, cervical, colorectal, and head and neck tumors. We identify known cancer-associated pathogens consistent with the literature. In addition, we identify a significant prevalence of Fusobacterium in head and neck tumors, comparable to colorectal tumors. The Fusobacterium-high subgroup of head and neck tumors occurs mutually exclusive to human papillomavirus, and is characterized by overexpression of miRNAs associated with inflammation, elevated innate immune cell fraction and nodal metastases. We validate the association of Fusobacterium with the inflammatory markers IL1B, IL6 and IL8, miRNAs hsa-mir-451a, hsa-mir-675 and hsa-mir-486-1, and MMP10 in the tongue tumor samples. A higher burden of Fusobacterium is also associated with poor survival, nodal metastases and extracapsular spread in tongue tumors defining a distinct subgroup of head and neck cancer.

Landscape of toll-like receptors expression in tumor microenvironment of triple negative breast cancer (TNBC): Distinct roles of TLR4 and TLR8.

TNBC is the most aggressive and hormone receptor-negative subtype of breast cancer with molecular heterogeneity in bulk tumors hindering effective treatment. Toll-like receptors (TLRs) have the potential to ignite diverse immune responses in the tumor microenvironment (TME). This encouraged us to screen their transcript expression in the publically available TCGA datasets. Reported molecular subtypes of TNBC may represent different TMEs and we observed differentially expressed TLRs (DETs) i.e. TLR3/4/6/8/9 have unique expression pattern in the TNBC subtypes, particularly in Immunomodulatory (IM) TNBC subtype. We then dissected expression of the DETs in immune and other components of the TME. TLR4 and TLR8 showed significant (p-value ≤ 0.05) negative partial correlation with tumor purity compared to other DETs. Interestingly, TLR4 and TLR8 expression showed a significant (adjusted p-value ≤ 0.05) correlation with different subsets of immune infiltrating cells having the highest correlation with monocytes/macrophage/dendritic cell populations mediating both innate and adaptive response in TNBC. The co-expression network identified genes correlated with these immune cells. Further, GSEA analysis of co-expressed genes showed a significant association of TLR8 partners with 'Peptide ligand binding', 'Gά-signaling', and 'Cytokine-cytokine interaction' while TLR4 associated genes correlated with 'Adaptive immune system' and 'Systemic lupus erythematosus' interactome. Finally, the expression of TLR4 protein was validated in a panel of TNBC cell lines. TLR4 expression in chemoresponsive TNBC was also validated in TNBC cell lines upon Paclitaxel (PTX) treatment. Collectively, the present study identified specific DETs in TNBC and discovered a prospective role of TLR4 and TLR8 in the maintenance of tumor-immune-microenvironment.

Molecular characterization of lung squamous cell carcinoma tumors reveals therapeutically relevant alterations.

INTRODUCTION: Unlike lung adenocarcinoma patients, there is no FDA-approved targeted-therapy likely to benefit lung squamous cell carcinoma patients. MATERIALS AND METHODS: We performed survival analyses of lung squamous cell carcinoma patients harboring therapeutically relevant alterations identified by whole exome sequencing and mass spectrometry-based validation across 430 lung squamous tumors. RESULTS: We report a mean of 11.6 mutations/Mb with a characteristic smoking signature along with mutations in TP53 (65%), CDKN2A (20%), NFE2L2 (20%), FAT1 (15%), KMT2C (15%), LRP1B (15%), FGFR1 (14%), PTEN (10%) and PREX2 (5%) among lung squamous cell carcinoma patients of Indian descent. In addition, therapeutically relevant EGFR mutations occur in 5.8% patients, significantly higher than as reported among Caucasians. In overall, our data suggests 13.5% lung squamous patients harboring druggable mutations have lower median overall survival, and 19% patients with a mutation in at least one gene, known to be associated with cancer, result in significantly shorter median overall survival compared to those without mutations. CONCLUSIONS: We present the first comprehensive landscape of genetic alterations underlying Indian lung squamous cell carcinoma patients and identify EGFR, PIK3CA, KRAS and FGFR1 as potentially important therapeutic and prognostic target.