Genomic diversity andBCL9Lmutational status in CTC pools predict overall survival in metastatic colorectal cancer

Abstract The genomic diversity of circulating tumor cells (CTCs) and its clinical implications remain poorly understood. In this study, we characterized the mutational landscape of CTC pools stemming from 29 metastatic colorectal cancer (mCRC) patients and examined its relationship with disease progression. Our analysis revealed substantial variation in mutational burden among patients, with all CTC pools harboring non-silent mutations in key CRC driver genes. Importantly, higher genomic diversity in CTC pools was significantly associated with reduced overall survival. Furthermore, non-silent mutations in BCL9L emerged as a strong predictor of patient survival. Taken together, these findings underscore the potential of CTC genomic profiling as a promising prognostic tool in mCRC and highlight the need for further research into its clinical applications. Competing Interest Statement The authors have declared no competing interest. Funding Statement This work was supported by the Spanish Ministry of Science and Innovation - MICINN (PID2019-106247GB-I00 awarded to DP) and by an AXA Research Fund postdoctoral grant (awarded to J.M.A.). DP receives further support from the Galician government (ED431C 2022/26). JMA is currently supported by an AECC-Investigator grant (INVES20007FERN). R.P. is currently supported by an AECC-Investigator grant (INVES234992PINE). L.M.R. is supported by a contract Miguel Servet from ISCIII (CP20/00119). Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All samples were obtained and collected after written informed consent from all subjects using a protocol approved by the Clinical Ethics Committee of Pontevedra-Vigo-Ourense (2018/301 approved 19/06/2018). This study was approved by the Clinical Ethics Committee of Pontevedra-Vigo-Ourense I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Footnotes Competing interests: The authors declare no competing interests. In this version, we have updated the analysis by including additional clinical variables (lines of treatment) and the latest clinical survival details. Data availability Raw exome sequencing data from CTC pools, together with matching healthy samples, have been deposited in the Sequence Read Archive database under the accession code ########. All data supporting the findings of this study are available within the article and its supplementary information files.