Prognostic Analysis Of Hormone Receptor Positive T1 Stage Breast Cancer And The Establishment Of Prognostic Model

Objective: To study the clinicopathological features and prognostic factors of HR+ HER2-type T1 stage(?2cm)breast cancer,and establish a low-cost,intuitive and convenient prognostic model to screen out HR+ HER2-type T1 stage(? 2cm)breast cancer patients who could benefit from chemotherapy.Method:Data of this study come from a total of 1448 patients with breast cancer after surgery from January 1,2002 to December 31,2015 in the Department of Oncology of First Affiliated Hospital of China Medical University.According to the screening criteria,270 eligible patients with HR+,HER2-type T1 stage(?2cm)breast cancer were screened out.The general information,pathological data,and treatment status of these 270 patients were collected and summarized.Then,we established HR+,HER2-type T1 stage(?2cm)breast cancer patients' database and analyzed the factors affecting its prognosis.All data were analyzed by SPSS 16.0 software.Univariate and multivariate analyzes of DFS and OS were carried out with cox risk proportional model.Survival analysis used Kaplan-Meier curve and the difference between groups used Log-rank test.Nomogram prognostic model was established by using The R Project for Statistical Computing 3.4.3 software(http://www.R-project.org)and the independent prognostic factors from the multivariate analysis of the cox risk proportional model were substituted into the nomogram.1000 Bootstrap self-sampling methods were used for internal verification,and the prediction accuracy of this model was measured by the Harrell's concordance index(C-index).P value <0.05 for the difference was statistically significant.The ROC curve was drawn according to the total score shown in the nomogram.The maximum value of the "Youden index" was used as the cut-off point to classify the high,medium and low risk groups.The cox proportional hazards model was used to investigate the effect of ?chemotherapy or not?,? cycles of chemotherapy? and ?chemotherapy programme? on the prognosis of high,middle and low-risk groups.Thereby,we distinguish the group of HR +,HER2-type T1-stage(? 2cm)breast cancer who could benefit from adjuvant chemotherapy.Results:The follow-up ended on January 1,2017.There were 7 cases(2.59%)lost in 270 cases,24 DFS cases(8.89%),and 6 OS cases(2.22%).The DFS of 5 years and 10 years were 95.56% and 91.85% respectively.The OS of 5 years and 10 years were 100% and 98.52% respectively.Univariate analysis showed that tumor diameter,lymph node metastasis number,ER receptor intensity,and endocrine therapy were related to DFS of HR+,HER2-type T1 stage(?2cm)breast cancer patients.The lymph node metastasis number and histological grade of were related to OS;Multivariate analysis showed that the tumor diameter,number of lymph node metastasis and intensity of ER receptor are independent prognostic factors affecting DFS.The number of lymph node metastasis is the independent prognostic factor affecting OS.The larger the HR+,HER2-type T1 stage(?2cm)breast cancer tumor diameter,the more lymph node metastases,the lower the ER receptor intensity,and the poorer the prognosis.Using the independent prognostic factors-tumor diameter,number of lymph node metastasis,ER intensity,to establish a nomographic prognostic model.After 1000 bootstrap self-sampling internal verification,Bootstrap-corrected C-index was 0.811(95% CI 0.727-0.895,P <0.001),demonstrating that the nomogram model was better resolved.The ROC curve was plotted and the maximum value of the "Youden index" was taken as the cut-off point.It obtained that the total score of the nomogram less than 107 was the low-risk group,107 to 175 was the medium-risk group,and the total score higher than 175 was high-risk group.For low and medium risk groups,whether chemotherapy or not,chemotherapy cycles and the choice of chemotherapy regimen did not affect DFS,P> 0.05.For high-risk groups,the number of chemotherapy cycles and chemotherapy regimen did not affect DFS,P> 0.05.But whether chemotherapy or not was significantly correlated with DFS,p=0.010.Chemotherapy patients' prognosis was significantly better than non-chemotherapy patients.Conclusion :1.Tumor diameter,number of lymph node metastasis and ER expression intensity are the clinicopathological factors affecting the prognosis of HR+,HER2-type T1 stage breast cancer.2.The nomographic prognostic model can predict the prognosis of HR+,HER2-type T1 stage breast cancer.3.For medium and low risk group,adjuvant endocrine therapy may be given alone without chemotherapy,while high-risk patients should be given adjuvant chemotherapy.Chemotherapy protocol and number of chemotherapy cycles shall be selected according to patient comorbidity,tolerance,risk-benefit ratio and others..