Abstract: Objective To investigate the expression of RIN1 in breast cancer, and analyze its association with the prognosis. Methods To analyze the tissues of 85 breast cancer and 20 benign breast disease patients by immunhistochemical techniques, and followed up the 85 cases of breast cancer; RIN1 in 20 cases of breast cancer and adjacent tissues’ expressions by Real Time PCR and Western blot assay. Kaplan – Meier survival analyze the average survival time.Results A varying degrees of RIN1 were expressed in 85 cases of breast cancer ,high expression in 44 cases,RIN1 was highly expressed in breast cancer than in no-cancer tissues (p﹤0.05);The expression of RIN1 were significantly associated with tumor size、histological grade、family history (p﹤0.05). the average survival time of high expression group was significantly shorter than low expression group(p﹤0.05).The high expression of RIN1 was related to the tumor disease-free survival (p﹤0.05). mRNA and its protein were expressed in 20 cases of breast cancer and its adjacent tissues. The expression of RIN1 mRNA and its protein significantly increased in cancer tissues.Conclusion RIN1 expression played a role in breast cancer pathogenesis and Maybe its high expression could be used as prognostic marker in breast cancer.

Key words: Breast cancer, RIN1, prognosis