Association of different traditional Chinese medicine treatment strategies with overall survival in patients with metastatic colorectal cancer: a multicenter real-world cohort study

Background Traditional Chinese medicine (TCM) is commonly used as part of integrated care for metastatic colorectal cancer (mCRC), but survival outcomes associated with different TCM treatment strategies in routine practice remain uncertain. We evaluated the association between three TCM treatment strategies and overall survival (OS). Methods This multicenter ambispective cohort included patients with mCRC treated at three tertiary hospitals between 2017 and 2024. Patients were classified into the Quxie Capsule group (QX group), the High-TCM group, and the Low-TCM group. Overlap weighting (OW) with weighted Cox regression was the primary analysis, with conventional multivariable Cox regression for validation. A 90-day landmark analysis was applied across all three groups, and a delayed-entry time-dependent Cox model was used for the High-TCM versus Low-TCM duration comparison. Results A total of 540 patients were included (60 QX, 344 High-TCM, and 136 Low-TCM). Median OS was 40.8, 26.0, and 22.6 months, respectively (overall log-rank P < 0.001). In the OW analysis, QX was associated with lower mortality than High-TCM (HR = 0.51, 95% CI 0.27–0.96, P = 0.038) and Low-TCM (HR = 0.41, 95% CI 0.28–0.62, P < 0.001), whereas Low-TCM versus High-TCM was not statistically significant (HR = 1.22, 95% CI 0.75–2.00, P = 0.429). In the delayed-entry High-TCM/Low-TCM analysis, sustained TCM exposure was associated with lower mortality than short-term or not-yet-sustained exposure (HR = 0.76, 95% CI 0.60–0.97, P = 0.025). Conclusion TCM treatment strategy was associated with OS in this multicenter real-world cohort of patients with mCRC. A Quxie Capsule-based strategy was associated with longer survival after overlap weighting, and time-dependent analysis supported an association between sustained Chinese herbal medicine treatment and lower mortality. These findings support further prospective evaluation of Quxie Capsule-based and sustained TCM strategies as components of integrated care for mCRC.