〔Abstract〕 Objective By collecting various clinical data during chemotherapy of breast cancer patients, we can discover the influencing factors of liver function abnormalities in breast cancer patients during chemotherapy, and establish a risk prediction model.To find out the influencing factors of liver function abnormalities in breast cancer patients during chemotherapy by collecting various clinical data during chemotherapy, and to establish a risk prediction model. Methods Epidemiological questionnaire surveys, clinical biochemical tests and blood sample collection were conducted for admitted breast cancer patients, and the age, tumor type, tumor TNM staging, chemotherapy regimen and other data of breast cancer patients were analyzed during chemotherapy, and decision trees were used to construct breast glands cancer chemotherapy drug-induced liver injury risk prediction model.During this period, Tangshan People′s Hospital admitted a total of 675 breast cancer patients, and all were women.According to the inclusion and exclusion criteria of the study subjects, it was found that demographic information, clinical biochemical indicators, and blood samples were collected from complete a total of 640 breast cancer patients.EpiData 3.0 was used to establish a database, and R software was used for statistical analysis. Results A total of 640 breast cancer patients were investigated.After chemotherapy, 106 breast cancer patients developed liver damage, the prevalence rate was 16.56%.The proportion of patients with drug-induced liver injury(22.82%) in the 60-80-year-old age group was higher than that in other age groups, and the incidence of liver injury showed an upward trend with age(P<0.05).The rates of liver injury in breast cancer patients who had been menopausal and breast cancer patients with a long-term medication history were 21.17% and 17.32%,respectively, which were higher than those of non-menopausal and liver-impaired patients without long-term medication history.The difference was statistically significant(P<0.05).Tumor pathology classification, tumor TNM staging, and chemotherapy regimens were all related to the incidence of drug-induced liver injury in breast cancer patients.Among them, the incidence of liver injury in the combined drug group in the chemotherapy regimen was 20.67%,which is significantly higher than that of other drug groups.There was statistical significance(P<0.05).The decision tree model for breast cancer chemotherapy drug-induced liver injury risk screened out three observational indicators for predicting liver injury risk: age, tumor TNM stage and combination medication group.These three indicators were correct in predicting the risk of breast cancer chemotherapy drug-induced liver injury The rate was 92.19%,and the sensitivity and specificity were 86.36% and 93.40%. Conclusion Age, menopause, long-term medication history, tumor pathology classification, tumor TNM staging, and chemotherapy regimens are the influencing factors for liver injury in breast cancer patients during chemotherapy.Combining the above influencing factors, a risk prediction model for breast cancer chemotherapy drug-induced liver injury is established to realize individualized treatment of patients and ensure the smooth progress of chemotherapy for breast cancer patients.