Patients with metastatic colorectal cancer whose disease has stopped responding to standard chemotherapy face sharply limited options, and a newly registered clinical trial now aims to find out whether laboratory-grown fragments of their own tumors can steer doctors toward better choices. The DSEE-CRC trial, described in a study protocol published in BMC Cancer, will randomize patients with chemotherapy-refractory metastatic colorectal cancer to either treatment guided by functional precision cancer medicine or to the standard third-line regimen of trifluridine-tipiracil combined with bevacizumab.
The protocol was published on 28 October 2026 as an open-access article, and the version shared at this stage is a peer-reviewed, accepted manuscript that remains subject to further editorial edits before the final version of record appears.
Eligible patients must have failed first-line standard chemotherapy for unresectable, measurable metastases located in the liver, peritoneum, or superficial lymph nodes, and they must have at least one lesion that can be reached by biopsy. This requirement matters because the entire strategy depends on obtaining fresh tumor tissue that can be kept alive outside the body long enough for meaningful drug testing.
These tumoroids are exposed to more than 20 anti-cancer drugs, and the resulting pattern of sensitivity and resistance is compiled into an in-vitro diagnostic report that summarizes and ranks the drug responses observed in the laboratory.
Randomization occurs only after second-line chemotherapy has failed, with patients assigned in a 2:1 ratio. Two-thirds receive investigational therapy selected according to the tumoroid drug-sensitivity report, while the remaining third receive trifluridine-tipiracil with bevacizumab, the currently accepted standard third-line option. This design allows the trial to compare the guided approach directly against routine care in the same patient population.
The primary objective is not to measure survival benefit directly but to evaluate the diagnostic performance of the tumoroid-guided approach, asking whether the laboratory test correctly identifies therapies that will control disease. Clinical endpoints include disease control rates at prespecified intervals until treatment failure, along with progression-free survival, overall survival, and safety. The protocol also incorporates assessments of relevant quality-of-life domains and an economic evaluation of the cost-effectiveness of tumoroid-informed therapy.
The investigators emphasize that the trial addresses both the efficacy and the safety of precision cancer medicine in late-stage colorectal cancer, while also confronting a practical hurdle: the regulatory challenges of simultaneously investigating medicinal products and a new in-vitro diagnostic device for precision oncology. Because the drug guidance depends on a diagnostic test that must itself be validated, the study has to satisfy requirements that apply to both a therapeutic strategy and a laboratory assay.
Because the published document is a study protocol, it describes planned methods rather than results, and no findings about whether tumoroid-guided therapy improves outcomes yet exist. The trial’s registered design, however, lays out a concrete path for testing whether growing a patient’s tumor in the laboratory and challenging it with dozens of drugs can translate into better-informed treatment decisions at a stage of disease where options are running out.
Subject of Research: A randomized trial protocol testing patient-derived tumoroid-guided therapy against standard third-line treatment in chemotherapy-refractory metastatic colorectal cancer.
Article Title: Functional precision medicine for chemotherapy-refractory metastatic colorectal cancer: the randomized DSEE-CRC trial
Article References: Ree, A. H., Eide, P. W., Meltzer, S., Bousquet, P. A., Fuglestad, A. J., Dahle-Smith, Å., Negård, A., Leland-Try, M., Holmedal, S. H., Augestad, K. M., Andreassen, C. A., Lüders, T., Bordin, D. L., Tahiri, A., Wang, S., Aas, E., Brahme, C.-J., Wangheim, M., Sjögren, A., & Bruun, J. (2026). Functional precision medicine for chemotherapy-refractory metastatic colorectal cancer: the randomized DSEE-CRC trial. BMC Cancer. https://doi.org/10.1186/s12885-026-17265-8
Image Credits: AI Generated
DOI: 10.1186/s12885-026-17265-8
Keywords: colorectal cancer, functional precision medicine, patient-derived tumoroids, DSEE-CRC trial, drug sensitivity testing, trifluridine-tipiracil, bevacizumab, in-vitro diagnostic, clinical trial protocol, third-line therapy, metastatic cancer, Functional
News Source: Nathaniel Bowman. (October 28, 2026). Randomized DSEE-CRC trial will test tumoroid-guided therapy in refractory metastatic colorectal cancer. Scienmag.
