Colorectal cancer (CRC) continues to rank among the most frequently diagnosed and deadliest cancers globally. Despite improvements in therapy that have extended the survival of patients with metastatic colorectal cancer (mCRC), there is still a shortage of effective biomarkers to inform treatment choices and guide clinical management. In this investigation, we employed a refined flow cytometry workflow to detect, quantify, and classify extracellular vesicles (EVs) in peripheral blood obtained from 54 individuals with mCRC and 48 healthy control participants matched by age and sex. Clinical outcomes, including overall survival (OS) and overall response rate (ORR), were assessed in patients who received first-line fluoropyrimidine-based chemotherapy.
The study revealed that mCRC patients exhibited markedly elevated circulating levels of total EVs as well as CD133+ and EPCAM+ EV subsets relative to healthy controls. Survival analyses indicated that patients with higher pre-treatment concentrations of total EVs and CD133+ EVs experienced significantly worse OS (p = 0.001 and p = 0.0001, respectively). Additionally, increased baseline levels of CD133+ EVs were associated with a diminished ORR to initial systemic therapy (p = 0.045).
Overall, these results highlight the potential value of blood-based EV profiling—particularly CD133+ EVs—as a source of new prognostic biomarkers that could enhance risk assessment and support more tailored therapeutic strategies for individuals with mCRC.
