High-throughput molecular assays for inclusion in personalised oncology trials - State-of-the-art and beyond.

In the last decades, the development of high-throughput molecular assays has revolutionised cancer diagnostics, paving the way for the concept of personalised cancer medicine. This progress has been driven by the introduction of such technologies through biomarker-driven oncology trials. In this review, strengths and limitations of various state-of-the-art sequencing technologies, including gene panel sequencing (DNA and RNA), whole-exome/whole-genome sequencing and whole-transcriptome sequencing, are explored, focusing on their ability to identify clinically relevant biomarkers with diagnostic, prognostic and/or predictive impact. This includes the need to assess complex biomarkers, for example microsatellite instability, tumour mutation burden and homologous recombination deficiency, to identify patients suitable for specific therapies, including immunotherapy. Furthermore, the crucial role of biomarker analysis and multidisciplinary molecular tumour boards in selecting patients for trial inclusion is discussed in relation to various trial concepts, including drug repurposing. Recognising that today's exploratory techniques will evolve into tomorrow's routine diagnostics and clinical study inclusion assays, the importance of emerging technologies for multimodal diagnostics, such as proteomics and in vivo drug sensitivity testing, is also discussed. In addition, key regulatory aspects and the importance of patient engagement in all phases of a clinical trial are described. Finally, we propose a set of recommendations for consideration when planning a new precision cancer medicine trial.

Current and emerging sequencing-based tools for precision cancer medicine.

Current precision cancer medicine is dependent on the analyses of a plethora of clinically relevant genomic aberrations. During the last decade, next-generation sequencing (NGS) has gradually replaced most other methods for precision cancer diagnostics, spanning from targeted tumor-informed assays and gene panel sequencing to global whole-genome and whole-transcriptome sequencing analyses. The shift has been impelled by a clinical need to assess an increasing number of genomic alterations with diagnostic, prognostic and predictive impact, including more complex biomarkers (e.g. microsatellite instability, MSI, and homologous recombination deficiency, HRD), driven by the parallel development of novel targeted therapies and enabled by the rapid reduction in sequencing costs. This review focuses on these sequencing-based methods, puts their emergence in a historic perspective, highlights their clinical utility in diagnostics and decision-making in pediatric and adult cancer, as well as raises challenges for their clinical implementation. Finally, the importance of applying sensitive tools for longitudinal monitoring of treatment response and detection of measurable residual disease, as well as future avenues in the rapidly evolving field of sequencing-based methods are discussed.

Precision cancer medicine: Concepts, current practice, and future developments.

Precision cancer medicine is a multidisciplinary team effort that requires involvement and commitment of many stakeholders including the society at large. Building on the success of significant advances in precision therapy for oncological patients over the last two decades, future developments will be significantly shaped by improvements in scalable molecular diagnostics in which increasingly complex multilayered datasets require transformation into clinically useful information guiding patient management at fast turnaround times. Adaptive profiling strategies involving tissue- and liquid-based testing that account for the immense plasticity of cancer during the patient's journey and also include early detection approaches are already finding their way into clinical routine and will become paramount. A second major driver is the development of smart clinical trials and trial concepts which, complemented by real-world evidence, rapidly broaden the spectrum of therapeutic options. Tight coordination with regulatory agencies and health technology assessment bodies is crucial in this context. Multicentric networks operating nationally and internationally are key in implementing precision oncology in clinical practice and support developing and improving the ecosystem and framework needed to turn invocation into benefits for patients. The review provides an overview of the diagnostic tools, innovative clinical studies, and collaborative efforts needed to realize precision cancer medicine.

Implementation of precision medicine in healthcare-A European perspective.

The technical development of high-throughput sequencing technologies and the parallel development of targeted therapies in the last decade have enabled a transition from traditional medicine to personalized treatment and care. In this way, by using comprehensive genomic testing, more effective treatments with fewer side effects are provided to each patient-that is, precision or personalized medicine (PM). In several European countries-such as in England, France, Denmark, and Spain-the governments have adopted national strategies and taken "top-down" decisions to invest in national infrastructure for PM. In other countries-such as Sweden, Germany, and Italy with regionally organized healthcare systems-the profession has instead taken "bottom-up" initiatives to build competence networks and infrastructure to enable equal access to PM. In this review, we summarize key learnings at the European level on the implementation process to establish sustainable governance and organization for PM at the regional, national, and EU/international levels. We also discuss critical ethical and legal aspects of implementing PM, and the importance of access to real-world data and performing clinical trials for evidence generation, as well as the need for improved reimbursement models, increased cross-disciplinary education and patient involvement. In summary, PM represents a paradigm shift, and modernization of healthcare and all relevant stakeholders-that is, healthcare, academia, policymakers, industry, and patients-must be involved in this system transformation to create a sustainable, non-siloed ecosystem for precision healthcare that benefits our patients and society at large.

KRAS G12C Mutant Non-Small Cell Lung Cancer Linked to Female Sex and High Risk of CNS Metastasis: Population-based Demographics and Survival Data From the National Swedish Lung Cancer Registry.

BACKGROUND: Real-world data on demographics related to KRAS mutation subtypes are crucial as targeted drugs against the p.G12C variant have been approved. METHOD: We identified 6183 NSCLC patients with reported NGS-based KRAS status in the Swedish national lung cancer registry between 2016 and 2019. Following exclusion of other targetable drivers, three cohorts were studied: KRAS-G12C (n = 848), KRAS-other (n = 1161), and driver negative KRAS-wild-type (wt) (n = 3349). RESULTS: The prevalence of KRAS mutations and the p.G12C variant respectively was 38%/16% in adenocarcinoma, 28%/13% in NSCLC-NOS and 6%/2% in squamous cell carcinoma. Women were enriched in the KRAS-G12C (65%) and KRAS-other (59%) cohorts versus KRAS-wt (48%). A high proportion of KRAS-G12C patients in stage IV (28%) presented with CNS metastasis (vs. KRAS-other [19%] and KRAS-wt [18%]). No difference in survival between the mutation cohorts was seen in stage I-IIIA. In stage IV, median overall survival (mOS) from date of diagnosis was shorter for KRAS-G12C and KRAS-other (5.8 months/5.2 months) vs. KRAS wt (6.4 months). Women had better outcome in the stage IV cohorts, except in KRAS-G12C subgroup where mOS was similar between men and women. Notably, CNS metastasis did not impact survival in stage IV KRAS-G12C, but was associated with poorer survival, as expected, in KRAS-other and KRAS-wt. CONCLUSION: The KRAS p.G12C variant is a prevalent targetable driver in Sweden and significantly associated with female sex and presence of CNS metastasis. We show novel survival effects linked to KRAS p.G12C mutations in these subgroups with implications for clinical practice.

UROSCAN and UROSCANSEQ: a large-scale multicenter effort towards translation of molecular bladder cancer subtypes into clinical practice - from biobank to RNA-sequencing in real time.

BACKGROUND: Bladder cancer is molecularly one of the most heterogenous malignancies characterized by equally heterogenous clinical outcomes. Standard morphological assessment with pathology and added immunohistochemical analyses is unable to fully address the heterogeneity, but up to now treatment decisions have been made based on such information only. Bladder cancer molecular subtypes will likely provide means for a more personalized bladder cancer care. METHODS: To facilitate further development of bladder cancer molecular subtypes and clinical translation, the UROSCAN-biobank was initiated in 2013 to achieve systematic biobanking of preoperative blood and fresh frozen tumor tissue in a population-based setting. In a second phase, we established in 2018 a parallel logistic pipeline for molecular profiling by RNA-sequencing, to develop and validate clinical implementation of molecular subtyping and actionable molecular target identification in real-time. RESULTS: Until June 2021, 1825 individuals were included in the UROSCAN-biobank, of which 1650 (90%) had primary bladder cancer, 127 (7%) recurrent tumors, and 48 (3%) unknown tumor status. In 159 patients, multiple tumors were sampled, and metachronous tumors were collected in 83 patients. Between 2016 and 2020 the UROSCAN-biobanking included 1122/2999 (37%) of all primary bladder cancer patients in the Southern Healthcare Region. Until June 2021, the corresponding numbers subjected to RNA-sequencing and molecular subtyping was 605 (UROSCANSEQ), of which 52 (9%) samples were not sequenced due to inadequate RNA-quality (n = 47) or technical failure/lost sample (n = 5). CONCLUSIONS: The UROSCAN-biobanking and UROSCANSEQ-infrastructure for molecular subtyping by real-time RNA-sequencing represents, to our knowledge, the largest effort of evaluating population-wide molecular classification of bladder cancer.

Building a precision medicine infrastructure at a national level: The Swedish experience.

Precision medicine has the potential to transform healthcare by moving from one-size-fits-all to personalised treatment and care. This transition has been greatly facilitated through new high-throughput sequencing technologies that can provide the unique molecular profile of each individual patient, along with the rapid development of targeted therapies directed to the Achilles heels of each disease. To implement precision medicine approaches in healthcare, many countries have adopted national strategies and initiated genomic/precision medicine initiatives to provide equal access to all citizens. In other countries, such as Sweden, this has proven more difficult due to regionally organised healthcare. Using a bottom-up approach, key stakeholders from academia, healthcare, industry and patient organisations joined forces and formed Genomic Medicine Sweden (GMS), a national infrastructure for the implementation of precision medicine across the country. To achieve this, Genomic Medicine Centres have been established to provide regionally distributed genomic services, and a national informatics infrastructure has been built to allow secure data handling and sharing. GMS has a broad scope focusing on rare diseases, cancer, pharmacogenomics, infectious diseases and complex diseases, while also providing expertise in informatics, ethical and legal issues, health economy, industry collaboration and education. In this review, we summarise our experience in building a national infrastructure for precision medicine. We also provide key examples how precision medicine already has been successfully implemented within our focus areas. Finally, we bring up challenges and opportunities associated with precision medicine implementation, the importance of international collaboration, as well as the future perspective in the field of precision medicine.

Trailblazing precision medicine in Europe: A joint view by Genomic Medicine Sweden and the Centers for Personalized Medicine, ZPM, in Germany.

Over the last decades, rapid technological and scientific advances have led to a merge of molecular sciences and clinical medicine, resulting in a better understanding of disease mechanisms and the development of novel therapies that exploit specific molecular lesions or profiles driving disease. Precision oncology is here used as an example, illustrating the potential of precision/personalized medicine that also holds great promise in other medical fields. Real-world implementation can only be achieved by dedicated healthcare connected centers which amass and build up interdisciplinary expertise reflecting the complexity of precision medicine. Networks of such centers are ideally suited for a nation-wide outreach offering access to precision medicine to patients independent of their place of residence. Two of these multicentric initiatives, Genomic Medicine Sweden (GMS) and the Centers for Personalized Medicine (ZPM) initiative in Germany have teamed up to present and share their views on core concepts, potentials, challenges, and future developments in precision medicine. Together with other initiatives worldwide, GMS and ZPM aim at providing a robust and sustainable framework, covering all components from technology development to clinical trials, ethical and legal aspects as well as involvement of all relevant stakeholders, including patients and policymakers in the field.

Quantification of microRNA editing using two-tailed RT-qPCR for improved biomarker discovery.

Even though microRNAs have been viewed as promising biomarkers for years, their clinical implementation is still lagging far behind. This is in part due to the lack of RT-qPCR technologies that can differentiate between microRNA isoforms. For example, A-to-I editing of microRNAs through adenosine deaminase acting on RNA (ADAR) enzymes can affect their expression levels and functional roles, but editing isoform-specific assays are not commercially available. Here, we describe RT-qPCR assays that are specific for editing isoforms, using microRNA-379 (miR-379) as a model. The assays are based on two-tailed RT-qPCR, and we show them to be compatible both with SYBR Green and hydrolysis-based chemistries, as well as with both qPCR and digital PCR. The assays could readily detect different miR-379 editing isoforms in various human tissues as well as changes of editing levels in ADAR-overexpressing cell lines. We found that the miR-379 editing frequency was higher in prostate cancer samples compared to benign prostatic hyperplasia samples. Furthermore, decreased expression of unedited miR-379, but not edited miR-379, was associated with treatment resistance, metastasis, and shorter overall survival. Taken together, this study presents the first RT-qPCR assays that were demonstrated to distinguish A-to-I-edited microRNAs, and shows that they can be useful in the identification of biomarkers that previously have been masked by other isoforms.

[Genomic Medicine Sweden - a national initiative for the broad introduction of precision medicine in Swedish healthcare]. / Genomic Medicine Sweden ­ initiativ för brett införande.

The Genomic Medicine Sweden (GMS) initiative aims to strengthen precision medicine across the country. This will be accomplished through the implementation of large-scale sequencing techniques in Swedish healthcare. With a patient-centered view, initial efforts will focus on rare diseases, cancer, pharmacogenomics, and infectious diseases, and subsequently extend to complex diseases. GMS is being implemented as a broad collaborative project involving healthcare, universities with medical faculty, SciLifeLab, industry and patient organizations. To deliver top tier diagnostics, regional genomic medicine centers (GMC) are currently under establishment together with a national informatics infrastructure for data sharing. GMS will also offer a unique resource for research that could pave the way for the development of novel drugs, and enhance collaboration with industry. In summary, GMS provides Sweden with an opportunity to take an international forefront position in the field of precision medicine.

[Molecular pathology - the key to precision oncology]. / Molekylär patologi ­ nyckeln till målinriktad cancerbehandling.

Rapidly expanding knowledge of the molecular landscape of cancers has resulted in the implementation of an increasing number of specific therapies targeted at tumors with specific molecular aberrations. In response to this development, new tools for predictive testing for molecular targets need to be implemented in routine health care. To achieve robust future molecular diagnostic pathology, and equal opportunity for patients to qualify for targeted therapy, the national working group for Solid Tumors in the initiative Genomic Medicine Sweden (GMS) aims to implement regional and national platforms for comprehensive genomic tumor profiling and linked analysis pipelines. Novel IT-infrastrucutures and recruitment of bioinformaticians and molecular biologists to hospital labotatories are paramount. The infrastructure will allow wider inclusion into clinical trials and supplement the national cancer registries with molecular ¼real world data« for research and evaluation of implemented cancer therapies and diagnostic procedures.

Clinical Utility of Targeted Sequencing in Lung Cancer: Experience From an Autonomous Swedish Health Care Center.

OBJECTIVES: Mutation analysis by massive parallel sequencing (MPS) is routinely performed in the clinical management of lung cancer in Sweden. We describe the clinical and mutational profiles of lung cancer patients subjected to the first 1.5 years of treatment predictive MPS testing in an autonomous regional health care region. METHODS: Tumors from all patients with lung cancer who had an MPS test from January 2015 to June 2016 in the Skåne health care region in Sweden (1.3 million citizens) were included. Six hundred eleven tumors from 599 patients were profiled using targeted sequencing with a 26-gene exon-focused panel. Data on disease patterns and characteristics of the patients subjected to testing were assembled, and correlations between mutational profiles and clinical features were analyzed. RESULTS: MPS with the 26-gene panel revealed alterations in 92% of the 611 lung tumors, with the most frequent mutations detected in the nontargetable genes TP53 (62%) and KRAS (37%). Neither KRAS nor TP53 mutations were associated with disease pattern, chemotherapy response, progression-free survival, or overall survival in advanced-stage disease treated with platinum-based doublet chemotherapy as a first-line treatment. Among targetable genes, EGFR driver mutations were detected in 10% of the tumors, and BRAF p.V600 variants in 2.3%. For the 71 never smokers (12%), targetable alterations (EGFR mutations, BRAF p.V600, MET exon 14 skipping, or ALK/ROS1 rearrangement) were detected in 59% of the tumors. CONCLUSION: Although the increasing importance of MPS as a predictor of response to targeted therapies is indisputable, its role in prognostics or as a predictor of clinical course in nontargetable advanced stage lung cancer requires further investigation.

Integration of next-generation sequencing in clinical diagnostic molecular pathology laboratories for analysis of solid tumours; an expert opinion on behalf of IQN Path ASBL.

The clinical demand for mutation detection within multiple genes from a single tumour sample requires molecular diagnostic laboratories to develop rapid, high-throughput, highly sensitive, accurate and parallel testing within tight budget constraints. To meet this demand, many laboratories employ next-generation sequencing (NGS) based on small amplicons. Building on existing publications and general guidance for the clinical use of NGS and learnings from germline testing, the following guidelines establish consensus standards for somatic diagnostic testing, specifically for identifying and reporting mutations in solid tumours. These guidelines cover the testing strategy, implementation of testing within clinical service, sample requirements, data analysis and reporting of results. In conjunction with appropriate staff training and international standards for laboratory testing, these consensus standards for the use of NGS in molecular pathology of solid tumours will assist laboratories in implementing NGS in clinical services.

The expression pattern of matrix-producing tumor stroma is of prognostic importance in breast cancer.

BACKGROUND: There are several indications that the composition of the tumor stroma can contribute to the malignancy of a tumor. Here we utilized expression data sets to identify metagenes that may serve as surrogate marker for the extent of matrix production and vascularization of a tumor and to characterize prognostic molecular components of the stroma. METHODS: TCGA data sets from six cancer forms, two breast cancer microarray sets and one mRNA data set of xenografted tumors were downloaded. Using the mean correlation as distance measure compact clusters with genes representing extracellular matrix production (ECM metagene) and vascularization (endothelial metagene) were defined. Explorative Cox modeling was used to identify prognostic stromal gene sets. RESULTS: Clustering of stromal genes in six cancer data sets resulted in metagenes, each containing three genes, representing matrix production and vascularization. The ECM metagene was associated with poor prognosis in renal clear cell carcinoma and in lung adenocarcinoma but not in other cancers investigated. Explorative Cox modeling using gene pairs identified gene sets that in multivariate models were prognostic in breast cancer. This was validated in two microarray sets. Two notable genes are TCF4 and P4HA3 which were included in the sets associated with positive and negative prognosis, respectively. Data from laser-microdissected tumors, a xenografted tumor data set and from correlation analyses demonstrate the stroma specificity of the genes. CONCLUSIONS: It is possible to construct ECM and endothelial metagenes common for several cancer forms. The molecular composition of matrix-producing cells, rather than the extent of matrix production seem to be important for breast cancer prognosis.

GREM1 and POLE variants in hereditary colorectal cancer syndromes.

Hereditary factors are thought to play a role in at least one third of patients with colorectal cancer (CRC) but only a limited proportion of these have mutations in known high-penetrant genes. In a relatively large part of patients with a few or multiple colorectal polyps the underlying genetic cause of the disease is still unknown. Using exome sequencing in combination with linkage analyses together with detection of copy-number variations (CNV), we have identified a duplication in the regulatory region of the GREM1 gene in a family with an attenuated/atypical polyposis syndrome. In addition, 107 patients with colorectal cancer and/or polyposis were analyzed for mutations in the candidate genes identified. We also performed screening of the exonuclease domain of the POLE gene in a subset of these patients. The duplication of 16 kb in the regulatory region of GREM1 was found to be disease-causing in the family. Functional analyses revealed a higher expression of the GREM1 gene in colorectal tissue in duplication carriers. Screening of the exonuclease domain of POLE in additional CRC patients identified a probable causative novel variant c.1274A>G, p.Lys425Arg. In conclusion a high penetrant duplication in the regulatory region of GREM1, predisposing to CRC, was identified in a family with attenuated/atypical polyposis. A POLE variant was identified in a patient with early onset CRC and a microsatellite stable (MSS) tumor. Mutations leading to increased expression of genes can constitute disease-causing mutations in hereditary CRC syndromes.

miR-145 suppress the androgen receptor in prostate cancer cells and correlates to prostate cancer prognosis.

Androgen signalling through the androgen receptor (AR) is essential for prostate cancer initiation, progression and transformation to the lethal castration-resistant state. The aim of this study was to characterize the mechanisms by which miR-145 deregulation contribute to prostate cancer progression. The miR-145 levels, measured by quantitative reverse transcription-polymerase chain reaction, were found to inversely correlate with occurrence of metastases, survival and androgen deprivation therapy response in a well-characterized prostate cancer cohort. Introduction of ectopic miR-145 in prostate cancer cells generated an inhibitory effect on the AR at both transcript and protein levels as well as its activity and downstream targets prostate-specific antigen (PSA), kallikrein-related peptidase 2 and TMPRSS2. The regulation was shown to be mediated by direct binding using Ago2-specific immunoprecipitation, but there was also indication of synergetic AR activation. These findings were verified in clinical prostate specimens by demonstrating inverse correlations between miR-145 and AR expression as well as serum PSA levels. In addition, miR-145 was found to regulate androgen-dependent cell growth in vitro. Our findings put forward novel possibilities of therapeutic intervention, as miR-145 potentially could decrease both the stem cells and the AR expressing bulk of the tumour and hence reduce the transformation to the deadly castration-resistant form of prostate cancer.

Prognostic stromal gene signatures in breast cancer.

INTRODUCTION: Global gene expression analysis of tumor samples has been a valuable tool to subgroup tumors and has the potential to be of prognostic and predictive value. However, tumors are heterogeneous, and homogenates will consist of several different cell types. This study was designed to obtain more refined expression data representing different compartments of the tumor. METHODS: Formalin-fixed paraffin-embedded stroma-rich triple-negative breast cancer tumors were laser-microdissected, and RNA was extracted and processed to enable microarray hybridization. Genes enriched in stroma were identified and used to generate signatures by identifying correlating genes in publicly available data sets. The prognostic implications of the signature were analyzed. RESULTS: Comparison of the expression pattern from stromal and cancer cell compartments from three tumors revealed a number of genes that were essentially specifically expressed in the respective compartments. The stroma-specific genes indicated contribution from fibroblasts, endothelial cells, and immune/inflammatory cells. The gene set was expanded by identifying correlating mRNAs using breast cancer mRNA expression data from The Cancer Genome Atlas. By iterative analyses, 16 gene signatures of highly correlating genes were characterized. Based on the gene composition, they seem to represent different cell types. In multivariate Cox proportional hazard models, two immune/inflammatory signatures had opposing hazard ratios for breast cancer recurrence also after adjusting for clinicopathological variables and molecular subgroup. The signature associated with poor prognosis consisted mainly of C1Q genes and the one associated with good prognosis contained HLA genes. This association with prognosis was seen for other cancers as well as in other breast cancer data sets. CONCLUSIONS: Our data indicate that the molecular composition of the immune response in a tumor may be a powerful predictor of cancer prognosis.