Stiffness-dependent MSC homing and differentiation into CAFs - implications for breast cancer invasion.

Cellular heterogeneity and extracellular matrix (ECM) stiffening have been shown to be drivers of breast cancer invasiveness. Here, we examine how stiffness-dependent crosstalk between cancer cells and mesenchymal stem cells (MSCs) within an evolving tumor microenvironment regulates cancer invasion. By analyzing previously published single-cell RNA sequencing datasets, we establish the existence of a subpopulation of cells in primary tumors, secondary sites and circulatory tumor cell clusters of highly aggressive triple-negative breast cancer (TNBC) that co-express MSC and cancer-associated fibroblast (CAF) markers. By using hydrogels with stiffnesses of 0.5, 2 and 5 kPa to mimic different stages of ECM stiffening, we show that conditioned medium from MDA-MB-231 TNBC cells cultured on 2 kPa gels, which mimic the pre-metastatic stroma, drives efficient MSC chemotaxis and induces stable differentiation of MSC-derived CAFs in a TGFß (TGFB1)- and contractility-dependent manner. In addition to enhancing cancer cell proliferation, MSC-derived CAFs on 2 kPa gels maximally boost local invasion and confer resistance to flow-induced shear stresses. Collectively, our results suggest that homing of MSCs at the pre-metastatic stage and their differentiation into CAFs actively drives breast cancer invasion and metastasis in TNBC.

Microfluidics-based EGFR mutation detection and its implication in the resource-limited clinical setting.

Management of lung cancer today obligates a mutational analysis of the epidermal growth factor receptor (EGFR) gene particularly when Tyrosine Kinase Inhibitor (TKI) therapy is being considered as part of prognostic stratification. This study evaluates the performance of automated microfluidics-based EGFR mutation detection and its significance in clinical diagnostic settings. Formalin-fixed, paraffin-embedded (FFPE) samples from NSCLC patients (n = 174) were included in a two-phase study. Phase I: Validation of the platform by comparing the results with conventional real-time PCR and next-generation sequencing (NGS) platform. Phase II: EGFR mutation detection on microfluidics-based platform as part of routine diagnostics workup. The microfluidics-based platform demonstrates 96.5% and 89.2% concordance with conventional real-time PCR and NGS, respectively. The system efficiently detects mutations across the EGFR gene with 88.23% sensitivity and 100% specificity. Out of 144 samples analysed in phase II, the platform generated valid results in 94% with mutation detected in 41% of samples. This microfluidics-based platform can detect as low as 5% mutant allele fractions from the FFPE samples. Therefore the microfluidics-based platform is a rapid, complete walkaway, with minimum tissue requirement (two sections of 5 µ thickness) and technical skill requirement. The method can detect clinically actionable EGFR mutations efficiently and can be considered a reliable diagnostic platform in resource-limited settings. From receiving samples to reporting the results this platform provides accurate data without much manual intervention. The study helped to devise an algorithm that emphasizes effective screening of the NSCLC cases for EGFR mutations with varying tumour content. Thus it helps in triaging the cases judiciously before proceeding with multigene testing.

Heat Induced Processing of Cellblocks with Significant Reduction in Overall Turn Around Time.

Introduction: Cellblock (CB) with immunohistochemistry (IHC) is practically indispensable in the diagnostic workup of serous effusions; however, CB requires a minimum of 15-20 h for routine histopathological processing. A reduction in processing time can expedite a faster diagnosis. Aim: This study was undertaken to evaluate the utility of the heat-induced CB (HICB) technique. Material and Methods: Two sets of agar-embedded CBs were processed from 50 effusion samples. CBs were further processed by conventional and rapid methods. Conventional CBs (CCB) were processed in a histoprocessor, whereas rapid CB was processed in a heated water bath with an agitation facility. For HICB processing, dehydration and clearing were performed at 50°C followed by paraffin wax impregnation at 65°C temperature. From both CBs, sections of 5 um thickness were cut and stained with hematoxylin and eosin (H and E). Cell morphology, cost, and time were compared between the two methods. The feasibility of IHC was attempted in a few cases. Results: HICB was completed within 4.30 h compared with CCB. Diagnoses on both CBs were concordant in all the cases. Incomplete dehydration was noted in six (12%) cases, but the diagnosis was not compromised. No additional cost was involved in HICB. On IHC, both HICB and CCB exhibited equivalent expression. Conclusions: HICB is a rapid, innovative, simple, and cost-effective technique and expedites faster diagnosis. It does not require any advanced equipment.

Targeted molecular profiling of solid tumours-Indian tertiary cancer centre experience.

PURPOSE: Molecular Profiling of solid tumours is extensively used for prognostic, theranostic, and risk prediction. Next generation sequencing (NGS) has emerged as powerful method for molecular profiling. The present study was performed to identify molecular alterations present in solid tumours in Indian tertiary cancer centre. METHODS: Study included 1140 formalin Fixed paraffin embedded samples. NGS was performed using two targeted gene panels viz. Ampliseq Focus panel and Sophia Solid Tumor Plus Solution. Data was analyzed using Illumina's Local Run Manager and SOPHiA DDM software. Variant interpretation and annotations were done as per AMP/ACMG guidelines. RESULTS: Total 896 cases were subjected to NGS after excluding cases with suboptimal nucleic acid quality/quantity. DNA alterations were detected in 64.9% and RNA fusions in 6.9% cases. Among detected variants, 86.7% were clinically relevant aberrations. Mutation frequency among different solid tumours was 70.8%, 67.4%, 64.4% in non-small cell lung (NSCLC), lung squamous cell carcinomas and head neck tumours respectively. EGFR, KRAS, BRAF, ALK and ROS1were commonly altered in NSCLC. Gastrointestinal tumours showed mutations in 63.6% with predominant alterations in pancreatic (88.2%), GIST (87.5%), colorectal (78.7%), cholangiocarcinoma (52.9%), neuroendocrine (45.5%), gall bladder (36.7%) and gastric adenocarcinomas (16.7%). The key genes affected were KRAS, NRAS, BRAF and PIK3CA. NGS evaluation identified co-occurring alterations in 37.7% cases otherwise missed by conventional assays. Resistance mutations were detected in progressive lung tumours (39.5%) against EGFR TKIs and ALK/ROS inhibitors. CONCLUSION: This is the largest Indian study on molecular profiling of solid tumours providing extensive information about mutational signatures using NGS.

Validation of Remote Digital Pathology based diagnostic reporting of Frozen Sections from home.

Background: Despite the promising applications of whole-slide imaging (WSI) for frozen section (FS) diagnosis, its adoption for remote reporting is limited. Objective: To assess the feasibility and performance of home-based remote digital consultation for FS diagnosis. Material & Method: Cases accessioned beyond regular working hours (5 pm-10 pm) were reported simultaneously using optical microscopy (OM) and WSI. Validation of WSI for FS diagnosis from a remote site, i.e. home, was performed by 5 pathologists. Cases were scanned using a portable scanner (Grundium Ocus®40) and previewed on consumer-grade computer devices through a web-based browser (http://grundium.net). Clinical data and diagnostic reports were shared through a google spreadsheet. The diagnostic concordance, inter- and intra-observer agreement for FS diagnosis by WSI versus OM, and turnaround time (TAT), were recorded. Results: The overall diagnostic accuracy for OM and WSI (from home) was 98.2% (range 97%-100%) and 97.6% (range 95%-99%), respectively, when compared with the reference standard. Almost perfect inter-observer (k = 0.993) and intra-observer (k = 0.987) agreement for WSI was observed by 4 pathologists. Pathologists used consumer-grade laptops/desktops with an average screen size of 14.58 inches (range = 12.3-17.7 inches) and a network speed of 64 megabits per second (range: 10-90 Mbps). The mean diagnostic assessment time per case for OM and WSI was 1:48 min and 5:54 min, respectively. Mean TAT of 27.27 min per case was observed using WSI from home. Seamless connectivity was observed in approximately 75% of cases. Conclusion: This study validates the role of WSI for remote FS diagnosis for its safe and efficient adoption in clinical use.

BRAF V600E Mutations and Beyond: A Molecular Perspective of Melanoma from a Tertiary Cancer Referral Center of India.

Vaibhavi VengurlekarObjectives Malignant melanoma demonstrates frequently occurring mutations of genes in the serine/threonine kinase pathway, namely BRAF, NRAS, and neurofibromin 1. There is rare documentation of a detailed analysis of these mutations in cases of melanoma among Indian patients. We present molecular features in cases of malignant melanoma, diagnosed at a tertiary cancer referral center in India, over a period of 8 years (2011-2018). Materials and Methods This study was performed on formalin fixed paraffin embedded tissues of 88 histologically confirmed cases of malignant melanoma. BRAF gene alterations were studied by both Sanger sequencing and real-time polymerase chain reaction techniques ( n = 74). Molecular testing for BRAF and NRAS gene alterations was accomplished in 74/88 cases (80%). Molecular test results were correlated with clinicopathological features using IBM SPSS Statistical software 25.0. Results The age ranged from 13 to 79 years (median = 57), with a M:F ratio of 1.4:1. BRAF mutations were observed in 12/74 (16.21%) patients, including V600E ( n = 7), A594T ( n = 1), T599 = ( n = 2), V600K ( n = 1), and Q612P ( n = 1), while NRAS mutations were observed in 6/38 (15.7%) patients. Among various subtypes, nodular melanoma was the most frequent subtype (33%) among cutaneous malignant melanomas. Among non-cutaneous melanomas, mucosal melanomas were observed in 37.5% of cases. Conclusion This constitutes one of the few reports on comprehensive analysis of molecular alterations underlying melanomas in Indian patients. A larger sample size, with more extensive molecular markers, would yield additional information on the disease manifestation.

Detection of MDM2 gene amplification on tissue microarray-based Fluorescence In-Situ Hybridization (FISH) in well-differentiated and dedifferentiated liposarcomas, displaying a wide morphological spectrum: A validation study at a tertiary cancer referral centre.

BACKGROUND: Liposarcomas including atypical lipomatous tumors (ALT)/well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPSs) display a histomorphological spectrum with their several diagnostic mimics. Murine double minute 2(MDM2) gene amplification characterizes ALT/WDLPS and DDLPS. Presently, there is no documented study from our subcontinent on the validation of MDM2 gene testing in these tumors. MATERIAL AND METHODS: Twenty-eight cases, diagnosed as ALT/WDLPS (n = 5) and DDLPSs (n = 23), along with 10 other tumors were tested for MDM2 gene amplification, using fluorescence in situ hybridization (FISH) on tissue microarrays (TMAs). Fourteen cases, diagnosed as ALT/WDLPS and DDLPS, along with 49 other tumors were tested for MDM2 immunostaining. Twenty tumors were tested for p16INK4a immunostaining. RESULTS: FISH was interpretable in 25 (89.2%) cases. Among the 20 cases diagnosed as DDLPSs, 19 displayed MDM2 gene amplification. Among the 5 cases diagnosed as ALT/WDLPS, four showed MDM2 gene amplification. Finally, 19 cases were confirmed as DDLPS and 4 as ALT/WDLPS. Furthermore, 7/19 cases confirmed as DDLPS and all 4 cases as ALT/WDLPS tested for MDM2 immunostaining, displayed its diffuse immunoexpression, while a single case of DDLPS showed its focal immunostaining. None of the 49 control cases displayed diffuse MDM2 immunoexpression. ALL 16 DDLPSs and 4 cases of ALT/WDLPS displayed p16INK4a immunostaining. The sensitivity for diffuse MDM2 immunostaining was 87.5% in cases of DDLPS, 100% in ALT/WDLPS, and specificity was 100%. The sensitivity for MDM2 gene amplification was 94.7% in cases of DDLPS and 100% in cases of ALT/WDLPS. The sensitivity for p16INK4a was 100%. CONCLUSION: This constitutes the first sizable study on MDM2 testing in ALT/WDLPS and DDLPS from our subcontinent using TMAs. MDM2 gene amplification testing continues as the diagnostic gold standard for ALTs/WDLPSs and DDLPSs and is useful in cases of diagnostic dilemmas. Diffuse MDM2 (IF2 clone) and p16INK4a immunostaining, together seem useful for triaging cases for FISH.

Impact of COVID-19 on quality checks of solid tumor molecular diagnostic testing-A surveillance by EQAS provider in India.

BACKGROUND: Molecular tests in solid tumours for targeted therapies call for the need to ensure precision testing. To accomplish this participation in the External Quality Assessment Program (EQAS) is required. This evaluates the consistency of diagnostic testing procedures and offers guidance for improving quality. Outbreak of COVID-19 pandemic led to worldwide lockdown and disruption of healthcare services including participation in EQAS.The present study describes the extended scope of EQAS offered byMPQAP (Molecular Pathology Quality Assurance Program), the first proficiency test provider for solid tumor diagnostics in India. The study surveys the preparedness of molecular testing laboratories in routine diagnostics and participation for quality assessment scheme. METHODS: A documented guideline for measures and precautions to be carried by testing laboratories in performing routine diagnostic tests during the lockdown period were charted and distributed to all MPQAP participant centres. A survey was conducted for MPQAP participants to check whether laboratories were involved in COVID-19 testing and to evaluate the impact of lockdown on the operations of diagnostics procedures. From the acquired response of the survey, 2 cycles out of initially proposed 11 cycles were executed with transformed approach using digital tools and image interpretation modules. FINDINGS: Out of 25 solid tumour testing laboratories registered as participants, 15 consented to participate in survey. The summary of survey conveyed the impact of COVID-19onroutine operations of diagnostics tests such as shortcomings in inventory and human resource management. Thirteen participants showed active willingness and consented to participate in EQAS test scheme. INTERPRETATIONS: The survey findings and assessment of EQAS cycles endorsed the quality testing procedures carried by participating laboratories throughout the lockdown. It highlighted the utility of EQAS participation during pandemic along with emphasis on safety measures for continual improvement in quality of diagnostic services.

COVID 19 pandemic testing time - Crisis or opportunity in disguise for India?

The current SARS-CoV-2 infection or the COVID 19 pandemic has taken the world by storm, where the best health care systems in the world seem to be overwhelmed and still this virus is eluding us as we are compelled to explore the preventive and/or therapeutic interventions to control the disease outbreak as well as to prevent deaths. In parallel to clinical services, laboratories have been overwhelmed with task of keeping up with ever increasing demand for testing. Real time PCR detection of COVID19 is the gold standard method, however, has certain shortcomings in terms of availability of infrastructure, reagents, consumables, and technical expertise. All these have paved the way for the alternative testing algorithms and strategies. Countries like United States and Italy have struggled with these issues. India has been criticized for not testing enough and not adopting the right policy, but has been managing the disease within its resource limited health care system to a fair extent. The present review provides the Indian perspective of COVID 19 testing, the journey from not testing enough in the past to a vast expanse and depth of testing in present time.