Association between Oral Chinese Herbal Medicine and Recurrence and Metastasis in Patients with Stages II and III Colorectal Cancer: A Cohort Study in China

Background: To evaluate the associations between long-term oral Chinese herbal medicines (CHMs) and recurrence and metastasis (R&M) in patients with stage II and III colorectal cancer (CRC). Furthermore, we aimed to determine the correlation between different syndrome patterns and prognosis and summarized the regularities among CHMs prescriptions, providing reference for clinical practice. Methods: An ambispective cohort study was conducted. All CRC patients who sought evaluation and treatment at Xiyuan Hospital and Beijing Cancer Hospital from August 2014 to August 2016 were included. In this study, "whether patients voluntarily take CHMs" was taken as the exposure factor, and the exposure degree was "the duration of CHM use." Stratification was performed according to the duration of TCM use to determine the relationship with R&M of CRC. The primary outcome was disease-free survival. Patients who had R&M of CRC after taking CHMs for ≥6 months were defined as "worst patients." R software was used for statistical analysis. The Kaplan-Meier method and Cox regression analysis were used to determine the prognosis. IBM SPSS was used to model a priori association rules; drug use rules were analyzed on this basis. Results: A total of 186 patients with stage II and III CRC after radical resection were enrolled. All patients reached the study endpoint by August 2021. The difference in disease-free survival between the two groups was most significant when the cutoff value for CHMs was 18 months (P = 0.0012). Multivariate analysis showed that 18 CHMs were independent protective factors for R&M of CRC (P = 0.001, HR = 0.20, 95% CI = 0.08-0.53). The ratio of Pi (spleen) and Shen (kidney) deficiency in the worst cases was higher than patients without R&M (P = 0.018). Sijunzi and Liuwei Dihuang decoctions were the most frequently used prescriptions in the anti-R&M phase. Conclusion: CHMs complying with the "Jianpi Bushen" principle may attenuate the risk of R&M in patients with stage II and III CRC. Pi (spleen) and Shen (kidney) deficiency in patients receiving TCM intervention for the first time within 6 months of radical resection may be associated with a higher CRC R&M rate. Further research is warranted to validate these findings and elucidate underlying biological mechanisms.