Objective To investigate the expression of claudin-1 in breast tumor tissues and the relationship of development and progress of breast neoplasm．Methods The expressions of claudin-1 in 89 cases of breast cancer and 37 benign breast diseases were tested by tissue chip technology and immunohistochemistry．The relationships of claudin-1 expression to the lymph node metastasis，TNM staging，maximum diameter of the tumor，and histology grade were statistically analyzed．Results The expression of claudin-1 in the breast cancer was significantly lower than that in the benign breast disease（χ2=19.20，P=0.000 2）．The claudin-1 expression in the patients with lymph node metastasis was significantly lower than that without lymph node metastasis （χ2=3.85，P=0.049 7）．The claudin-1 expression in the stageⅢ of TNM staging was weaker than that in the stage Ⅰ（χ2=5.29，P=0.021 4） and stage Ⅱ （χ2=7.46，P=0.006 3），respectively. There was no significant difference of the claudin-1 expression in the different maximum diameters of tumor （χ2=1.58，P=0.453 8） or histology grades （χ2=1.02，P=0.600 5），respectively．Conclusions The expression of claudin-1 might be correlated with the occurrence，development，and metastasis in breast tumor．It may be one of the potential indicator for lymph node metastasis and prognosis assessment in breast cancer．
With the acceleration of global innovative drug development, selecting safe, effective, and cost-effective products from numerous drugs has posed new challenges for the decision-making process of medical insurance drug access and dynamic updating of insurance directory. Real-world data (RWD) provides a new perspective for evaluation of clinical and economic value of drugs, but there are still uncertainties regarding the scope, quality standards, and evidence categories of RWD that can be used. Based on the current status of domestic and international RWD supporting the assessment of the clinical and economic value of drugs, this paper, in collaboration with national RWD and healthcare experts, has developed the key considerations for using real-world data to evaluate the clinical and economic value of drugs. This paper first clarifies the scope of RWD that can be used to evaluate the clinical and economic value of drugs evaluate; secondly, provides specific requirements and guidance on data attribution, data governance, and quality standards for RWD; finally, summarizes the evidence categories of RWD supporting evaluate the clinical and economic value of drugs evaluate.