The Relationship Between Post-neoadjuvant Chemotherapy Lymphocytic Infiltration In Residual Cancer And Prognosis In Breast Cancer Patients: A Meta-analysis

Background:Tumor infiltrating lymphocytes(TILs)are associated with the treatment and prognosis of breast cancer.However,whether TILs in residual breast tumors after neoadjuvant chemotherapy(NACT)is associated with prognosis requires further clarification.This study evaluated the relationship between post-neoadjuvant chemotherapy lymphocytic infiltration and the prognosis of breast cancer patients systematically,and provided a scientific basis for the treatment and prognosis of breast cancer.Methods:Pubmed,Embase,Cochrane Library,Web of Science,National Knowledge Infrastructure and Wanfang Database were searched for collecting post-neoadjuvant chemotherapy lymphocytic infiltration and breast cancer related literatures before March 1,2019.Hazard ratio(HR),95%confidence interval(95% CI),disease-free survival(DFS),recurrence-free survival(RFS),Metastasis-free survival(MFS)and overall survival(OS)were pooled in the meta-analysis.Then use RevMan 5.3 and Stata12.0 software to perform Meta-analysis.Results:11 studies were included in the meta-analysis with a total of breast cancer 945 patients.The results of meta-analysis showed that,for post-neoadjuvant chemotherapy lymphocytic infiltration in residual cancer,the H-TILs had a better DFS/RFS/MFS than that of the L-TILs[HR=0.35,95% CI(0.19,0.65),P=0.0008].Further subgroup analysis showed that for TNBC and HER2(+),the DFS/RFS/MFS of H-TILs were better than those of L-TILs [HR=0.33,95% CI(0.23,0.48),P<0.00001;HR = 0.25,95% CI(0.10,0.66),P = 0.005].As for post-neoadjuvant chemotherapy lymphocytic infiltration in residual cancer of TNBC,the OS of H-TILs was significantly better than those of L-TILs[HR=0.39,95% CI(0.27,0.56),P<0.00001].Conclusion: The level of TILs in post-neoadjuvant residual tumors has an important prognostic value for breast cancer,especially for HER2(+)and TNBC,H-TILs tend to have better prognosis than L-TILs as respect to the lower risk of death and disease.Due to the limited number of studies,a lot of researches and statistics are still needed at this stage to verify the above conclusions.