Expression and prognostic significance of TK1 and Ki67 in breast cancer

Abstract

Objective To investigate the effects of the expressions of thymidine kinase 1 (TK1) and Ki67 alone or their combination on the recurrence and metastasis of breast cancer.Methods Sixty-five samples were selected from the Second Affiliated Hospital of Guangzhou Medical University from March 2005 to June 2007,which were resected by surgical operation and confirmed as breast carcinoma by pathology.They were individed into two groups including 37 cases with recurrence or metastasis in 5 years (group A),28 cases without recurrence or metastasis in 5 years (group B).The expressions of TK1 and Ki67 in the two groups were detected by immunohistochemical staining assay.Then,Kaplan-Meier assay was used to describe survival curve.Results The positive expression rate of TK1 in group A was 91.8％,which was dramatically higher than that in group B 67.8％ (x2 =6.116,P =0.013).The positive expression rates of Ki67 in group A and B were 78.4％ and 42.9％ (x2 =8.635,P =0.003).The positive expression rates of TK1 combined with Ki67 in group A and B were 67.6％ and 39.3％ (x2 =5.159,P =0.023).Moreover,disease free survival of patients with positive expression of TK1 combined with Ki67 decreased significantly,compared with patients with positive expression of TK1 or Ki67 alone (x2 =6.137,P =0.046).Conclusion Positive expression of TK1 combined with Ki67 is the high risk factor of the reccurence or metastasis of breast carcinoma,and indicates poorer prognosis compared with positive expression alone. Key words: Breast neoplasms; Thymidine kinase; Ki67