Study On The Hazard Factors Of Distant Metastasis In Triple-negative Breast Cancer Patients Without Pathologic Complete Response After Neoadjuvant Chemotherapy

Research backgroundTriple negative breast cancer(TNBC)is a kind of breast cancer subtype with higher malignancy,which is prone to recurrence and metastasis in the early stage after treatment.NACT is one of the most important treatments in TNBC system.The study shows that the prognosis of patients who have achieved complete pathologic response(p CR)after NACT can be significantly improved.However,in clinical practice,most TNBC patients do not achieve p CR after NACT whose prognosis is still poor.Distant metastasis is an important factor affecting the survival period of patients,and TNBC has a higher distant metastasis rate compared with other subtypes of breast cancer.This study is aimed at analyzing the conditions of pathological response and prognosis of TNBC patients who have received NACT,and further explore the hazard factors of distant metastasis in patients who haven't achieved p CR so as to provide reference and basis for individualized treatment of such patients.MethodsRetrospectively analyze the clinicopathological data of 129 patients with triple negative breast cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2011 to June 2016.All patients received NACT before operation and surgical treatment in our hospital.Evaluate the curative effect through imaging examination and postoperative pathological diagnosis during NACT.p CR is defined as in primary lesion of breast and axillary lymph nodes,with no infiltrating residual of tumor cell.Record the recurrence and metastasis events and itsocurrence time of postoperative patients through follow-up.Analyze the relationship between p CR and the clinicopathological characteristics of patients after NACT through ? 2 test.Kaplan Meier carried out survival analysis and drew survival curve,compared prognosis of the patients with p CR and non-p CR patients,defined the distant metastasis-free Survival(DMFS)as the time from surgery to the first occurrence of distant metastasis,used Cox proportional hazards regression model to analyze the influencing factors of DMFS in patients with non-p CR.P is < 0.05,it means the difference is statistically significant.Results:1.The objective remission rate(ORR)of 129 patients with TNBC included in this study is 94.6% and the p CR rate is 27.1%(35 / 129).The expression level of initial tumor T stage and Ki67 is the associated factors of p CR after NACT(P < 0.05).Patients with T1 / T2 tumor and Ki67 high expression(> 30%)were more likely to achieve p CR.2.The median follow-up time of 129 patients is 52 months,the 5-year DMFS in patients with p CR and non-p CR are 94.3% and 59.4% respectively,and the 5-year OS are 96.3% and 71.0% respectively,the difference is statistically significant(P <0.05).3.Univariate Cox regression analysis shows that premenopause,initial tumor T3/ T4 stage,Ki67(> 30%)high expression,residual lesions > 2cm,positive pathological lymph nodes and lymphovascular invasion are hazard factors related to distant metastasis of patients with non-p CR after NACT(P < 0.05).The results of multivariable analysis show that the positive pathological lymph nodes(HR: 3.179;95% CI: 1.695-5.962;P = 0.001)and the presence of lymphovascular invasion(HR:HR:2.231;95%CI:1.370-3.633;P=0.021)are independent hazard factors for distant metastasis in patients with non-p CR.ConclusionCompared with the patients who achieved p CR,the patients without p CR have higher incidence of distant metastasis and poorer prognosis.Among the patients without p CR,positive pathological lymph nodes and the presence of lymphovascular invasion after operation could be used as an important hazard factor to predict distant metastasis,which has certain guiding significance for the follow-up treatment of such patients after NACT.