Abstract SY02-02: Understanding evolution of metastatic disease in renal cancer and melanoma

While our knowledge of the evolutionary features of primary tumors has grown exponentially over the last few years our understanding of evolution of metastases is more limited and many open questions remain, regarding the timing of metastatic dissemination, the acquisition of metastatic competence and the underpinning of the variety of metastatic phenotypes observed in the clinic from latent metastases to solitary and oligo-metastases to widespread metastases. We have leveraged unique translational protocols that allow interrogation of tumor evolution from the earliest stages of diseases to death to address some of these questions. In the context of renal cell cancers we show that the mode of evolution at the primary tumor site determines the tempo and distribution of systemic metastases; that the features that distinguish metastasis-competent clones included genome instability and aneuploidy; and that metastatic competence often emerges in the centre of the primary tumor. In the context of melanoma we observe a wide spectrum of metastatic seeding that includes organ-specific metastatic clones, monophyletic and polyphyletic seeding and polyclonal mixing at metastatic sites. We observe progressive increase in aneuploidy and occurrence of whole genome doubling as melanoma metastases progress and resist treatment suggesting this as a a mechanism of immune-evasion and treatment resistance. Citation Format: Samra Turajlic. Understanding evolution of metastatic disease in renal cancer and melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr SY02-02.