Abstract: ObjectiveTo approach the interrelation between telomerase activation and PCNA expression in breast cancer and evaluate the significance of combined detection in formulating therapeutic regimen after breast cancer operation.MethodThe level of telomerase activation and PCNA expression were detected in 80 cases of breast cancer,36 cases of side-cancer tissues and 10 cases of lacteal gland benign lesion using TRAP-PCR-ELISA and S-Pimmuno histochemistry technique.Results(1)The positive rate of telomerase in 80 breast cancer tissues and 36 side-cancer tissues were 65.0% and 8.3% respectively and the difference revealed statistical significance(P<0.01),the telomer ase activation was not examinated in 10 cases of lacteal gland benign lesion;Itis no significance in statistic that the level of positive rate of telomerase and the extent of axillary nodes metastasis(P>0.05).(2)Among 80 cases,the positive rate of PCNA in breast cancer tissues was 63.75% and the positive rate of PCNA in group with lymphatic metastasis was significantly higher than thatin group without lymphatic metastasis(P<0.01)and there was positive relationship between lymphatic metastasis and positive expression of PCNA(P<0.01).(3)The telomerase activation was in accordance with PCNA expression(P<0.01)and there was positive relationship between telomerase activation and PCNA(P<0.01),the concordance rate was 86.25%.ConclusionThe telomerase activation is in accordance with PCNA expression,associating telomerase activation with PCNA detection can provide the ancillary evidence to predict the prognosis and to formulate the treatment plan after breast cancer operation.