FANCD2 is involved in DNA damage repair and maintenance of chromosome stability.The purpose of this study was to investigate the expression of FANCD2 in sporadic breast cancer tissues and its association with clinicopathological features.A total of 162 Chinese women with invasive breast carcinoma who had no family history in first-degree relatives and 12 normal breast tissues were examined.The expression of FANCD2 was detected by immunohistochemical staining based on a tissue microarray technique.SAS system was used to analyze the data.Twenty-one out of the 162 invasive breast cancers(13%)were negative for FANCD2.The mean percentage of FANCD2 positive cells was significantly lower in breast cancers than in controls(P＜0.05).FANCD2 expression was significantly inversely associated with histological grade and TNM stage(P＜0.05),but not with axillary lymph node status or other conventional prognostic markers such as ER,PR,Her-2 and PCNA(P＞0.05).It was suggested that FANCD2 may play a critical role in breast carcinogenesis.It may become a valuable and independent marker for identifying women with sporadic breast cancer and evaluating the prognosis.