Abstract: ObjectiveTo investigate the protein expression of cell divison cycle 6（CDC6） and minichromosome maintennance 7（MCM7） in early gastric cardia cancer tissues and its clinical significance. MethodsFrom Mar 2009 to Dec 2014, 57 cases of early gastric cardia cancer tissues and paired adjacent normal tissues were collected. The expression of CDC6 and MCM7 in the above tissues were detected by immunohistochemistry.Furthermore， the relationships between protein levels of CDC6 and MCM7 with clinical features as well as prognosis were analyzed. ResultsThe positive rate of CDC6 expression in early gastric cardia cancer tissues was 33.3％， higher than that in adjacent tissues（14.0％）， and the difference was statistically significant（P＜0.05）.The positive rate of MCM7 expression in early cardia cancer tissues was 66.7％， higher than that in adjacent tissues （19.3％）， and the difference was statistically significant （P＜0.01）.The expression of CDC6 and MCM7 in early gastric cardia cancer tissues was both correlated with tumor differentiation（P＜0.05）， but not with age， gender and tumor volume（P＞0.05）. There was no significant correlation between CDC6 and MCM7（r=0.105， P＞0.05）. The overall survival of patients with different expression of CDC6 and MCM7 were not achieved. Patients with positive expression of CDC6 had better overall survival than those with negative expression， but the difference was not statistically significant （P=0.149）. Patients with positive expression of MCM7 had worse overall survival than those with negative expression， but the difference was not statistically significant （P=0.710）. ConclusionDysregulation of CDC6 and MCM7 expression occurs in early stage during the development of cardia cancer， and they are correlated with tumor differentiation， and may be related to the occurrence and development of cardia cancer.

Key words: Gastric cardia cancer, Immunohistochemistry, Cell division cycle 6（CDC6）, Minichromosome maitennance 7（MCM7）, Prognosis