Late-stage metastatic melanoma emerges through a diversity of evolutionary pathways
April 14, 2023
Abstract
Understanding the evolutionary pathways to metastasis and resistance to immune checkpoint inhibitors (ICI) in melanoma is critical for improving outcomes. Here we present the most comprehensive intra-patient metastatic melanoma dataset assembled to date as part of the PEACE research autopsy programme, including 222 exome, 493 panel-sequenced, 161 RNA-seq, and 22 single-cell whole-genome sequencing samples from 14 ICI-treated patients. We observed frequent whole-genome doubling and widespread loss of heterozygosity, often involving antigen presentation machinery. We found KIT extrachromosomal DNA may have contributed to the lack of response to KIT inhibitors of a KIT-driven melanoma. At the lesion-level, MYC amplifications were enriched in ICI non-responders. Single-cell sequencing revealed polyclonal seeding of metastases originating from clones with different ploidy in one of the patients. Finally, we observed that brain metastases that diverged early in molecular evolution emerge late in disease. Overall, our study illustrates the diverse evolutionary landscape of advanced melanoma.
Source:
Lavinia Spain, Alexander Coulton, Irene Lobon, Andrew Rowan, Desiree Schnidrig, Scott T.C. Shepherd, Benjamin Shum, Fiona Byrne, Maria Goicoechea, Elisa Piperni, Lewis Au, Kim Edmonds, Eleanor Carlyle, Nikki Hunter, Alexandra Renn, Christina Messiou, Peta Hughes, Jaime Nobbs, Floris Foijer, Hilda van den Bos, Rene Wardenaar, Diana C.J. Spierings, Charlotte Spencer, Andreas M. Schmitt, Zayd Tippu, Karla Lingard, Lauren Grostate, Kema Peat, Kayleigh Kelly, Sarah Sarker, Sarah Vaughan, Mary Mangwende, Lauren Terry, Denise Kelly, Jennifer Biano, Aida Murra, Justine Korteweg, Charlotte Lewis, Molly OFlaherty, Anne-Laure Cattin, Max Emmerich, Camille L. Gerard, Husayn Ahmed. Pallikonda, Joanna Lynch, Robert Mason, Aljosja Rogiers, Hang Xu, Ariana Huebner, Nicholas McGranahan, Maise Al Bakir, Jun Murai, Cristina Naceur-Lombardelli, Elaine Borg, Miriam Mitchison, David A. Moore, Mary Falzon, Ian Proctor, Gordon W H. Stamp, Emma L. Nye, Kate Young, Andrew J.S. Furness, Lisa Pickering, Ruby Stewart, Ula Mahadeva, Anna Green, James Larkin, Kevin Litchfield, Charles Swanton, Mariam Jamal-Hanjani, Samra Turajlic; Late-stage metastatic melanoma emerges through a diversity of evolutionary pathways. Cancer Discov 2023; https://doi.org/10.1158/2159-8290.CD-22-1427