Clinicopathological Characteristics And Prognosis Analysis Of Hormone Receptor Positive HER-2 Low Expression Breast Cancer

Objective:A retrospective study of operable hormone receptor(HR)positive and low expression of human epidermal growth factor-2(HER-2)in the clinical pathology characteristics and prognosis of breast cancer,to investigate the reasonableness of classification of this type of breast cancer as a new clinical treatment subcategory.Methods:Clinicopathologic data and follow up data of breast cancer patients undergoing operation for breast cancer in the breast surgery department of the First Affiliated Hospital of Nanchang University from January 2015 to December 2021 and were diagnosed as HR positive and HER-2 negative by pathology were collected for retrospective analysis.A total of 551 patients were classified into non-expression and low-expression groups according to HER-2 expression status.The clinicopathological characteristics(including age,fertility,family history of cancer,menstrual status,surgical method,histological grade,pathological type,and treatment status)and prognosis of the two groups were compared.Results:1.551 HR positive and HER-2 negative breast cancer patients,the group with low HER-2 expression included 318 patients(57.7%),the group with non HER-2expression included 233 patients(42.3%),the proportion of patients with low expression of HER-2 was higher.2.In HR positive HER-2 negative breast cancer,Compared with the group without HER-2 expression,patients with low HER-2 expression accounted for a higher proportion in T-stage 3-4(12.3% vs.6.4%,P=0.023),invasive ductal carcinoma(91.5% vs.82.0%,P=0.004),Ki-67 high expression(69.2% vs.60.5%,P=0.034),modified radical surgery(75.5% vs.66.5%,P=0.046).3.After a median follow-up of 50 months,in HR positive HER-2 negative breast cancer,recurrence and metastasis were found to be higher in patients with low expression of HER-2(18.6% vs.10.3%,P = 0.007).By means of univariate and multivariate COX proportional risk regression analysis,we found that HER-2expression status,estrogen receptor(ER)expression status,TNM staging,endocrine therapy and fertility status could influence the prognosis of HER-2 negative HR positive patients.HER-2 expression status is an independent prognostic factor of disease free survival(DFS)(HR=1.740,95% CI: 1.063-2.849,P=0.028).Conclusion:1.In HR positive HER-2 negative breast cancer,compared with HER-2 non expression group,HER-2 low expression group is more aggressive,with later stage at diagnosis and higher malignancy.2.In HR positive HER-2 negative breast cancer,compared with HER-2 non expression group,patients with HER-2 low expression have a higher risk of recurrence and metastasis,shorter DFS and worse prognosis.3.In HR positive HER-2 negative breast cancer,compared with HER-2 non expression group,breast cancer patients with HER-2 low expression have more aggressive clinicopathological characteristics and worse prognosis,and are related to HER-2 low expression status.HR positive HER-2 low expression may require clinical management as an independent subgroup to develop more effective treatments for HER-2 targets to further improve therapeutic efficacy and prognosis.