Clinicopathological Features And Prognostic Analysis Of The Breast Cancer With Low HER-2 Expression

Objectives:The success of new antibody-drug conjugates,Trastuzumab deruxtecan,in the breast cancer with HER-2 low expression may change the current treatment status of breast cancer,and There is an increasing interest in HER-2 low expression population.Therefore,it is necessary to study the clinicopathological features and prognosis of HER-2 low expression population.Methods:The data of primary breast cancer patients with HER-2 expression admitted to the Department of Breast and Thyroid Surgery of the First People’s Hospital of Yunnan Province from January 2018 to January 2020 were retrospectively collected.There were 304 HER-2 negative cases.The clinicopathological features of patients were stratified according to HR receptor and HER-2 status.The clinicopathological features and prognosis between patients with low HER-2expression and zero HER-2 expression were compared.Count data were expressed by frequency and percentage,and comparison was performed by using chi-square or Fisher’s exact test.Survival rates were calculated by Kaplan-Meier curve,and survival differences were compared by Breslow test.Cox regression analysis of univariate and multivariate prognostic factors.Bilateral test was used,and P<0.05 was considered statistically significant.Results: In 304 patients with HER-2 negative breast cancer,176 had HER-2 low expression(57.9%)and 128 had HER-2 zero expression(42.1%).Compared with the HER-2 zero expression group.There were significant statistical differences in age,menstrual status,histological grade,proliferation index and hormone receptor expression in the group with low HER-2 expression.Survival analysis shows there was no significant difference in DFS and OS between the two groups.Multivariate logistic analysis showed that tumor size and axillary status were influencing factors of DFS and OS.In 304 patients with HER-2 negative breast cancer,234(77.0%)were positive for hormone receptor,including 147(62.8%)with low expression of HER-2and 87(37.2%)with zero expression of HER-2.There were significant statistical differences in age,menstrual status and histological grading between the two groups.70(23.0%)were negative for hormone receptor,including 29(41.4%)with low expression of HER-2 and 41(58.6%)with zero expression of HER-2.There were significant statistical differences in TNM staging between the two groups.Conclusions: The breast cancer with HER-2 low expression has certain clinicopathological features.with the rise of new anti-HER-2 targeted drugs,it can be served as an independent clinical classification related to treatment.Also,it may become an independent biological subtype of breast cancer treatment research direction in the future,provides a more favorable theoretical basis for future HER-2low expression population to receive novel targeted drug therapy.No definitive conclusions can be drawn regarding the prognostic significance of the breast cancer with HER-2 low expression.