DNA Replication Error in Endometrial Carcinoma and Complex Atypical Endometrial Hyperplasia

We attempted to define the relation between DNA replication errors (RERs) in endometrial carcinomas and the precancerous lesion complex atypical endometrial hyperplasia (ATH) and clinicopathological characteristics. Tissue samples from 93 patients with endometrial carcinoma diagnosed as endometrioid adenocarcinoma and 26 patients with ATH (including 21 in whom endometrial carcinoma also was found) were prepared as formalin-fixed, paraffin-embedded sections. The samples were examined for the presence of RERs by the polymerase chain reaction with the use of five microsatellite markers. RERs were observed at ≥1 loci in 32 endometrial carcinoma patients (34%); all 26 ATH patients were RER negative. RERs were observed in 25% of stage I and stage II cancer patients (16/64) and in 55% of stage III and stage IV cancer patients (16/29) (P = 0.009), as well as in 63% (10/16) of cancer patients with and in 27% (20/75) of patients without lymph-node metastases (P = 0.013). The incidence of RERs was not related to patient age, histological tumor grade, or prognosis. These results suggest that RER may be involved in the advanced rather than the early stages of endometrioid adenocarcinoma. There appears to be little association between RER and ATH.