Abstract 272: Effective treatment of colorectal peritoneal metastases by exploiting a molecular subtype specific vulnerability

Abstract

Abstract In colorectal cancer, peritoneal metastases (PMs) associate with severe morbidity and dismal prognosis. Given the incidence of this disease and the lack of adequate treatments currently available, PMs pose a large unmet clinical need. Although PMs can be accompanied by more widespread metastatic disease, it often occurs as the only sign of dissemination. This implies that the route of metastatic spread to the peritoneum differs from that to distant organs. PMs are thought to result from cancer cells that spill into the abdominal cavity, and are able to attach to the peritoneal lining and form tumor deposits. This cascade places specific demands on the cancer cells. Here, we report that colorectal cancers that present with PMs almost universally classify as consensus molecular subtype 4 (CMS4). This previously recognized disease entity is characterized by mesenchymal features, poor prognosis, and resistance to therapies currently used against peritoneal metastases, which explains their limited efficacy. By leveraging disease models that capture CMS4-specific features, including the ability to form PMs in vivo, we identified elesclomol as a highly effective agent. Elesclomol kills cancer cells in a copper-dependent fashion by targeting the oxidative phosphorylation machinery, which we found to be a specific vulnerability of CMS4 cancers. Elesclomol-Cu2+ was effective following only minutes of exposure to CMS4 cell lines and organoids, supporting its use in intra-abdominal treatment procedures. It is therefore a promising candidate for the local treatment of peritoneal metastases of colorectal cancer. Citation Format: Sanne Bootsma, Mark P. Dings, Leandro Ferreira Moreno, Kristiaan J. Lenos, Louis Vermeulen, Maarten F. Bijlsma. Effective treatment of colorectal peritoneal metastases by exploiting a molecular subtype specific vulnerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 272.