Presentation on theme: "Acquisition of tumour multidrug resistance inevitable in most advanced solid tumours – Failing to cure the majority of advanced solid tumours – Declining."— Presentation transcript:
Acquisition of tumour multidrug resistance inevitable in most advanced solid tumours – Failing to cure the majority of advanced solid tumours – Declining therapeutic benefits at higher drug cost Drug resistance highly complex: – Approx 10% of kinases alter resistance to one or more drugs (Swanton et al 2007 Cancer Cell ; Swanton et al 2007 Cell Cycle) Failure of Biomarker Validation – 150,000 biomarkers only 100 for clinical use Predictive Biomarkers and Drug Resistance
Intratumour Heterogeneity Evidence of intratumour heterogeneity Possible Implications for biomarker studies Practical approaches to address heterogeneity
Breast Cancer Intra-tumour Heterogeneity Sector Ploidy Profiling and DNA Copy Number Analysis Multiple intermixed cell subpopulations within one tumour differ by large genomic events/focal amplifications/ deletions Navin N, et al. Genome Res 2010 Navin N, et al Nature 2011 Geyer and Reis-Filho J Path 2010 Shah and Aparicio Nature 2012
Does a Single Tumour Biopsy: Represent the tumour somatic/transcriptomic landscape ? Provide robust biomarkers of outcome ? Demonstrate that all mutations are ubiquitously present in every region of a tumour Predicted by a linear/clonal sweep model of tumour evolution Provide reliable data following Deep Sequencing Analysis to stratify patients for trials ?
Ubiquitous Shared Primary Shared Mets Private 65% mutations are heterogeneous and not present in every biopsy Primary Mets
Normal Evidence for Convergent Evolution SETD2 Loss of Function: H3K36 tri-methylation 3 distinct SETD2 mutations associated with loss of function: Mutational capacity?
Evidence intratumour heterogeneity may impact upon drug response? 6 weeks of Everolimus therapy Assess status of mTOR pathway across different regions of the tumour Evidence of Differential Pathway Activity post-Everolimus exposure?
mTOR active in all primary regions except R4 and metastases
Kinase Domain mTOR mutation L2431P Associated with Constitutive Activation of the mTOR Kinase
Kinase Domain mTOR mutation L2431P Lies in A Repressor Domain Close to Activation Loop of Kinase
Tracking Tumour Growth Seeding of metastatic sites can be tracked to one tumour region M2a,b M1 Chest Wall Metastasis Perinephric Metastasis Normal R9
Primary Tumour RegionsMetastatic Sites Primary Tumour RegionsMetastatic Sites Allelic Imbalance: ITH within Chest wall metastasis Only somatic mutations with >20x coverage were included Only somatic mutations with >20x coverage were included M2a,b M1 Chest Wall Metastasis Perinephric Metastasis R9
Primary Tumour RegionsMetastatic Sites Only somatic mutations with >20x coverage were included Only somatic mutations with >20x coverage were included Primary Tumour RegionsMetastatic Sites Heterogeneity of RCC Prognostic Signature Expression Median ccA 103 months ccB 24 months Genes upregulated in ccA Genes in ccB
Relevance of ITH and Cancer Branched Evolution Patient 1 Tumour Diversity Supports Evolutionary Fitness (Maley et al 2006) Tumour Adaptation and Selection for Drug resistance (Su et al 2012; Lee et al 2011) Metastatic growth (Yachida and Campbell 2010, Shah 2009) Tumour Sampling Bias Different tumour biopsies different results Sites of disease evolve independently Clonal Dominance and Actionable Mutations? Mutations present at one site but not another