Analysis of Factors Related to Lymph Node Metastasis Following Neoadjuvant Chemotherapy for Breast Cancer: Correlation Between Plasma Exosomal Circular RNA and Metastasis

Objective: To investigate the correlation between plasma exosomal circular RNA (circRNA) (non-invasive, dynamically monitorable) and lymph node metastasis following neoadjuvant chemotherapy in breast cancer and highlight its predictive superiority over traditional serum markers. Methods: The clinicopathological data and follow-up data of 487 patients with breast cancer who received neoadjuvant therapy in our hospital between 1 January 2018 and 1 January 2020 were retrospectively collected using convenience sampling. Following screening, 379 patients who met the inclusion and exclusion criteria were included in the analysis. The patients' data, including age, clinical TNM stage, tumour pathological type, tumour histological grade, tumour molecular typing, neoadjuvant regimen and course of treatment, were collected for analysis. Results: = 22.868, P < 0.001). The results of regression analysis showed that non-pCR (odds ratio [OR] = 2.320, 95% CI: 1.259-4.276), molecular subtype HER2+ (OR = 1.747, 95% CI: 1.070-2.852), histological grade II (OR = 3.159, 95% CI: 1.537-6.491), histological grade III (OR = 2.606, 95% CI: 1.242-5.466) and circRNA expression level (OR = 1.497, 95% CI: 1.398-1.602) were risk factors for postoperative metastasis in patients with breast cancer. The level of circRNA has predictive value for the occurrence of postoperative metastasis in breast cancer. The area under the curve was 0.955 (95% CI: 0.933-0.976), with a sensitivity of 87.4% and a specificity of 91.9%. Conclusion: Molecular typing, pCR status, histological grade and plasma exosomal circRNA expression level are independent predictors of recurrence and metastasis following neoadjuvant therapy. Notably, plasma exosomal circRNA, with its non-invasive and dynamic monitoring advantages, shows promising predictive potential for lymph node metastasis, providing a novel and superior clinical tool for prognosis assessment.