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This study was supported by Cancer Research UK, AstraZeneca and Pfizer UK. Introduction: Phase I of the Cancer Research UK Stratified Medicine Programme (SMP1) was designed to roll out molecular pathology testing nationwide at the point of cancer diagnosis, as well as facilitate an infrastructure where surplus cancer tissue could be used for research. It offered a non-trial setting to examine common UK cancer genetics in a real-world context. Methods: A total of 26 sites in England, Wales and Scotland, recruited samples from 7814 patients for genetic examination between 2011 and 2013. Tumour types involved were breast, colorectal, lung, prostate, ovarian cancer and malignant melanoma. Centralised molecular testing of surplus material from resections or biopsies of primary/metastatic tissue was performed, with samples examined for 3-5 genetic alterations deemed to be of key interest in site-specific cancers by the National Cancer Research Institute Clinical Study groups. Results: 10 754 patients (98% of those approached) consented to participate, from which 7814 tumour samples were genetically analysed. In total, 53% had at least one genetic aberration detected. From 1885 patients with lung cancer, KRAS mutation was noted to be highly prevalent in adenocarcinoma (37%). In breast cancer (1873 patients), there was a striking contrast in TP53 mutation incidence between patients with ductal cancer (27.3%) and lobular cancer (3.4%). Vast inter-tumour heterogeneity of colorectal cancer (1550 patients) was observed, including myriad double and triple combinations of genetic aberrations. Significant losses of important clinical information included smoking status in lung cancer and loss of distinction between low-grade and high-grade serous ovarian cancers. Conclusion: Nationwide molecular pathology testing in a non-trial setting is feasible. The experience with SMP1 has been used to inform ongoing CRUK flagship programmes such as the CRUK National Lung MATRIX trial and TRACERx. Publisher PDF

Acral melanoma is a rare subtype of melanoma found on the non-hair bearing surfaces of the skin. It is associated with a worse prognosis than cutaneous melanoma, with higher proportions of patients developing metastatic disease. Combination treatments targeting the MAP kinase (MAPK) pathway and immune checkpoint inhibitors have improved overall survival in patients with stage IV disease. However, resistance to both modalities remains a challenge. This is exemplified by our comprehensive analysis of a patient presenting with acral melanoma that developed resistance to both immune and targeted therapy. The patient developed metastatic disease in multiple sites and we obtained fresh tumour tissue and generated cell lines from a skin metastasis at baseline prior to nivolumab. Following an initial complete response, the patient developed new mediastinal lymph node and brain metastases, which were also resected. On further relapse, the patient commenced dabrafenib with a partial response. Despite ongoing extra-cranial control, the brain lesion progressed and was therefore resected. To investigate resistance to immune therapy, we performed comprehensive genomic analysis and gene expression profiling on the lesions from the three sites, which identified common mutations in all three lesions and a low overall mutational burden consistent with acral melanoma. Heterogeneity of the MHC class I and II restricted antigen profile of the pre-treatment subcutaneous metastasis versus lymph node and brain progressions could not account for the development of resistance to immunotherapy. Gene expression profiling revealed up-regulation of known mechanisms of immune tolerance in both the lymph node and brain metastasis compared to the pre-treatment subcutaneous metastasis. To investigate resistance to targeted therapy, we compared patient-derived cell lines from brain lesions taken pre (DabS) and on progression on dabrafenib (DabR), and showed ongoing sensitivity to dabrafenib despite the patient having progressed in the brain. When cells from the DabR cell line were cultured in cerebrospinal fluid (CSF) in the presence of dabrafenib, we observed a reduction in cell death. Thus, extrinsic factors present in CSF may have resulted in the progression of the brain lesion in this patient. Using a combination of platforms to study patient derived tissues, we show that immune editing through selection of cells with an immune resistant phenotype may have resulted in the resistance of this patient's tumours to immune therapy whilst resistance to MAPK targeted therapy could have been mediated by extrinsic factors in the CSF. Citation Format: Rebecca J. Lee, Maria Romina Girotti, Amaya Viros, Franziska Baenke, Amit Mandal, Garima Khandelwal, John Bridgeman, Elena Galvani, Gabriela Gremel, Milena Kalaitsidou, Garry Ashton, Isabel Peset, Matthew Smith, Jacqueline Swan, Kang Zeng, Haoran Tang, Caron Abbey, Robert Hawkins, Alberto Fusi, Crispin Miller, David Gilham, Nathalie Dhomen, Paul Lorigan, Richard Marais. Mechanisms of resistance to immuno and targeted therapies in acral melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2400.

Background:RET is a receptor tyrosine kinase (RTK) and forms part of a macromolecular receptor complex containing dimerised RET receptor, two co-receptors and a bound ligand. Signalling networks downstream of RET play an important role in regulating cell survival, differentiation, proliferation, migration and chemotaxis. Activating mutations in RET (e.g. C634W and M918T) are known drivers in medullary thyroid carcinomas (MTC). More recently, oncogenic RET fusions (e.g. CCDC6-RET and KIF5B-RET) have been identified in 1-2% of lung adenocarcinoma patients. We are currently developing novel, selective inhibitors of RET, and at the same time, investigating a number of biomarker approaches for the stratification of RET fusion-positive lung cancer patients who might benefit from such therapy. Methods: We have undertaken collaborative studies using established techniques including immunohistochemistry (IHC) and FISH (DNA break apart and RNA). In addition, we have investigated hybrid capture DNA sequencing of both biopsy material and circulating tumour DNA in the blood. Here we, compare and contrast the benefits of each biomarker assay evaluated and consider how these approaches could be translated for use in Phase I clinical trials at The Christie. Conclusion: Our data supports the successful implementation of predictive biomarkers to identify patients who might benefit from treatment with selective RET inhibitors. Acknowledgements:This work was funded by Cancer Research UK (Grant numbers C480/A1141 and C5759/A17098). Citation Format: Mandy Watson, Helen Small, Phil Chapman, Gemma Hopkins, Habiba Begum, Ian D. Waddell, Garry Ashton, Caron Abbey, Jade Harris, Mahmood Ayub, Sumitra Mohan, Dominic Rothwell, Ged Brady, Caroline Dive, Allan Jordan, Donald Ogilvie. RET inhibition: Development of novel compounds and a personalized medicine strategy in lung adenocarcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A176.