Objective    To study the relationship of the coexpression of APE1 and P53 with clinical related-parameters of the stages

international prognostic indexes

chemotherapeutic efficacy and prognosis in peripheral T-cell lymphomas (PTCLs).     Methods    Totally lymphoma specimens from 178 PTCLs patients were collected including 90 cases of peripheral T-cell lymphoma-unspecified (PTCL-U)

42 of extranodal NK/T cell lymphoma(NK/TL)

22 of anaplastic large T-cell lymphoma (ALCL)

20 of angioimmuno-blastic T-cell lymphoma (ATL)

and 4 of   subcutaneous panniculitis-like T-cell lymphoma（CTCL）. Expressions of APE1 and P53 were detected with immunohistochemical method in these 178 specimens. The correlations of the expressions of APE1 and P53 alone or combined together with the clinical features as well as prognosis were statistically analyzed with univariate and multivariate analyses.     Results    The APE1 expression and the P53 expression were positive in 147(82.6%) and 72 of 178 cases (40.5%) respectively. The positive rate of APE1 in the patients with ATL and PTCL-U was significantly higher than that in the patients with NK/TL

CTCL and ALCL (P0.05). Most patients with the APE1

+

/P53

+

coexpression were belonged to stage Ⅲ and Ⅳ and intermediate or high risk condition. The response rates of the patients in APE1

+

/P53

-

group and APE1

+

/P53

+

group were very lower than those of the patients in APE1

-

P53

-

group and APE1

-

P53

+

group (P0.01)

  meanwhile

the survival rates in APE1

+

/P53

-

group and PE1

+

/P53

+

group were significant lower than those in APE1

-

/P53

-

group and APE1

-

/P53

+

group(P0.01). The disease-free survival time in APE1

+

/P53

+

group was very lower than that in the other 3 groups

(P0.01). Univariate analysis showed that the positive expressions of APE1 or P53 and coexpression of APE1

+

/P53

-

and APE1

+

/P53

+

were significantly correlated with the poor prognosis all together (P0.05)

and the coexpressions of APE1

+

/P53

-

and APE1

+

/P53

+

were with 3-years survival rate respectively (P0.05 and P0.01). Multivariate analysis with the Cox regression models showed that the coexpression of APE1

+

/P53

+

was significantly associated with the poor prognosis(P0.01).     Conclusion    The respective expression of APE1

+

or P53

+

the coexpression of APE1

+

/P53

-

and APE1

+

/P53

+

are indicators of the poor prognosis in PTCLs patients; What’s more

the coexpression of APE1

+

/P53

+

may be also a independent prognosis factor for PTCLs.