Exploring the diagnostic and prognostic significance of circulating tumor cells in stage II-IV colorectal cancer using a nano-based detection method

Background: Colorectal cancer (CRC) is a leading cause of cancer mortality globally, underscoring the urgency for a noninvasive and effective biomarker to enhance patient prognosis. Circulating tumor cells (CTCs), a potential marker for real-time tumor monitoring, are limited in clinical utility due to the low sensitivity of existing detection methods. Previously, we introduced a novel nano-based CTCs detection method that relies on the electrical properties of cell surfaces, thus eliminating the need for specific molecular biomarkers. In this study, we used this technique to evaluate the diagnostic and prognostic value of CTCs in stage II-IV CRC. Methods: A total of 194 participants were included, consisting of 136 CRC patients and 58 healthy individuals. The peripheral blood of the participants was collected, and CTC enumeration was performed utilizing the nano-based detection method that we newly developed. The receiver operating characteristic (ROC) curve and multivariate Cox proportional-hazards analysis were used to assess the effectiveness of CTCs for diagnosing CRC and predicting patient prognosis. Results: The nano-based method demonstrated an ability to differentiate CRC patients from healthy individuals with a sensitivity of 84.6% and a specificity of 94.8%. Furthermore, baseline CTC levels were predictive of progression-free survival (PFS) in CRC patients, with lower levels associated with longer PFS compared to higher levels (4.5 vs 8.0 months at 15 CTCs/mL, p = 0.016; 4.4 vs 8.0 months at 20 CTCs/mL, p = 0.028). We also explored the dynamic changes in the number of CTCs after 1 to 5 cycles of chemotherapy. Patients with increasing CTC levels typically experienced disease progression (PD), while those with decreasing levels often achieved a partial response (PR) or maintained stable disease (SD). These findings suggest that the dynamic fluctuations in CTC counts are closely tied to the clinical course of the disease. Conclusion: Our study indicates the potential of nano-based CTCs detection in diagnosing and predicting outcomes for patients with stage II-IV CRC.