The Effect of Long-Term Traditional Chinese Medicine Treatment on Survival Time of Colorectal Cancer Based on propensity Score Matching: A Retrospective Cohort Study.

Objective. To explore the effect of long-term traditional Chinese medicine (TCM) treatment on survival time of colorectal cancer (hereinafter referred to as CRC). Methods. Our clinical study included patients who were diagnosed with CRC clinically or pathologically. Patients were divided into TCM treatment group and control group according to whether the modified Anti-cancer Decoction II Formula was applied for more than six months. Propensity score matching (hereinafter referred to as PSM) was used to further balance the covariates between groups. One-year to six-year progression-free survival rates of the two groups and the median progression-free survival (mPFS), median overall survival (mOS) of the two groups before and after PSM were calculated respectively. Furthermore, 15 factors that may affect the mPFS in CRC were included in COX multivariate regression analysis to explore the prognostic factors related to CRC as well as to analyze the risk ratio of different subgroups. Results. A total of 529 CRC patients were included in our study, 285 patients were in the TCM treatment group and 244 patients were in the control group. Before PSM, the mPFS and mOS in the TCM treatment group were 68 months and 75 months respectively, while mPFS and mOS in the control group were 40 months and 65 months respectively. After PSM, mPFS and mOS in the TCM treatment group were both 75 months, while mPFS and mOS in the control group were 28 months and 44 months respectively. One-year to six-year progression-free survival rates were 94.0%, 76.1%, 64.7%, 57.9%, 52.0%, 44.1% respectively in the TCM treatment group, and 78.6%, 61.4%, 51.7%, 40.8%, 33.0%, 29.1% respectively in the control group (p<0.01)(.) COX multivariate regression analysis indicated that surgery, chemotherapy and taking Chinese herbal decoction were protective factors for CRC recurrence and metastasis, while combining with intestinal obstruction, drinking history and family history were independent factors for CRC recurrence and metastasis. The results of subgroup analysis showed that the decoction of TCM could reduce the risk of recurrence and metastasis in each subgroup (p<0.01). The results of the survival analysis based on tumor stage demonstrated that patients may benefit from the long-term TCM treatment in the whole process, especially CRC patients with stage III similar to IV. Conclusions. Long-term TCM treatment by the usage of the modified Anti-cancer Decoction II Formula not only has a positive effect on the survival time of CRC patients, but also helps reduce the risk of recurrence and metastasis of CRC, which can be flexibly applied in the whole process of CRC treatment.