ABSTRACT
ObjectiveTo investigate whether severe myelosuppression after chemotherapy is associated with prognosis in patients with breast cancer. MethodsTriple negative breast cancer （TNBC） patients who received chemotherapy at the Second Affiliated Hospital of Nanchang University from May 2， 2013 to May 2， 2018 were divided into a control group （no/mild myelosuppression） and a case group （severe myelosuppression）. In this study， 251 patients with TNBC met the inclusion and exclusion criteria， including 125 patients in the control group （20 patients with grade 0 myelosuppression， 43 patients with grade I myelosuppression， 62 patients with grade Ⅱ myelosuppression）， 126 patients in the case group （114 patients with grade Ⅲ myelosuppression， 12 patients with grade Ⅳ myelosuppression）. The general clinicopathological data of the patients in the two groups， including age， pathological type of tumor， tumor T stage， tumor N stage， tumor Nottingham grade， intravascular cancer thrombus， were analyzed using the χ2 test. The disease-free survival （DFS） and overall survival （OS） of the two groups were analyzed using the Kaplan-Meier method. A Cox proportional hazards regression model with multiple factors was used to analyze the impact of post-chemotherapy severe myelosuppression on disease-free survival （DFS） and overall survival （OS） in patients with TNBC. ResultsThe differences in general clinicopathologic data between the two groups of patients were not statistically significant （all P＞0.05）. The 5-year disease-free survival （DFS） rate was significantly lower in the control group compared with the case group （75.2% vs. 85.7%， P=0.027）. However， there was no statistically significant difference in the 5-year overall survival （OS） rate between the two groups （88.8% vs. 95.2%， P=0.057）. The analysis of the multifactorial Cox proportional hazards regression model revealed that post-chemotherapy severe myelosuppression was an independent protective factor for disease-free survival （DFS） （HR=0.332， 95% CI： 0.173-0.638， P=0.001） and overall survival （OS） （HR=0.193， 95% CI： 0.062-0.602， P=0.005） in TNBC patients. ConclusionOur results show that TNBC patients with severe myelosuppression after chemotherapy have longer disease-free survival （DFS） than those with no/mild myelosuppression， and overall survival （OS） also tend to be prolonged compared with those with no/mild myelosuppression， and severe myelosuppression after chemotherapy can be used as an independent predictor of a good prognosis in breast cancer.