Abstract
BACKGROUND: Changes in circulating tumor cells (CTCs) before and after surgery and their association with lymph node metastasis and prognosis in resectable colorectal cancer (CRC) remain poorly understood. METHODS: In this prospective study, 81 patients with resectable CRC treated at Jiangyin People's Hospital from January 2023 to December 2024 were enrolled, along with 20 controls with adenoma. Preoperative and Postoperative peripheral blood CTCs were quantified using microfluidic chip technology. RESULTS: The median CTC count significantly declined from 16 per 5 ml to 4 after surgery (P < 0.001). Preoperatively, 76.6% were CTC-positive. Postoperatively, the CTC-positive rate decreased to 56.8% (P < 0.001). Of the 81 patients, 36 had lymph node metastasis (LNM), and 45 did not. Univariate analysis identified T3-4 stage, nerve invasion, vascular invasion, and preoperative CTC positivity as significant predictors of LNM (P < 0.05). Multivariate logistic regression confirmed vascular invasion (odds ratio [OR], 20.528; 95% CI, 4.296-98.086; P < 0.001) and preoperative CTC positivity (OR, 8.017; 95% CI, 1.138-56.482; P = 0.037) as independent risk factors for LNM. Prognostic analysis revealed that postoperative CTC-negative status was significantly associated with improved disease-free survival (DFS) (Log-rank P = 0.047). CONCLUSIONS: Preoperative CTC positivity was significantly associated with an increased risk of lymph node metastasis, supporting its potential role in assessing tumor aggressiveness. In addition, postoperative CTC positivity showed an exploratory association with shorter disease-free survival, suggesting a possible prognostic value that warrants further investigation.