Loss of hMLH1 expression is associated with less aggressive clinicopathological features in sporadic endometrioid endometrial adenocarcinoma.
OBJECTIVE
To assess the incidence and clinicopathological significance of microsatellite instability (MSI) and the protein expression of hMLH1 and hMSH2 in sporadic endometrioid endometrial adenocarcinoma (SEEA).


METHODS
A total of 50 patients with pure endometrioid sporadic endometrial adenocarcinoma were enrolled in the study. MSI analysis was done using five polymorphic markers (BAT26, D5S346, BAT25, D17S250, D2S123) and the protein expression of the hMLH1 and hMSH2 genes was determined by immunohistochemical staining. MSI was detected in 24% (12/50) of SEEA cases.


RESULTS
There was a significant correlation between MSI status and loss of hMLH1, hMSH2 expression, respectively. No significant association was found between MSI status and clinicopathological parameters, including age, grade, stage, depth of myometrial invasion, lymph-vascular space invasion (LVI), lymph node involvement or peritoneal cytology. However, significant correlations were found between loss of hMLH1 and a lower histological grade and the absence of LVI in patients with SEEA.


CONCLUSIONS
According to these results, MSI and a loss of protein expression of hMLH1 and hMSH2 may be associated with the pathogenesis of SEEA. In addition, hMLH1 immunostaining might have a role as a prognostic parameter. Further research using a large number of cases is needed to confirm our observations.
Ju
Woong
W
Department of Obstetrics and Gynecology, Ewha Womans University, College of Medicine, Seoul, Korea.
Park
Han Moie
HM
Lee
Shi Nae
SN
Sung
Sun Hee
SH
Kim
Seung Cheol
SC
D048868:Adaptor Proteins, Signal Transducing; D018269:Carcinoma, Endometrioid / Q000235:genetics* / Q000473:pathology*; D002352:Carrier Proteins / Q000235:genetics*; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D009363:Neoplasm Proteins / Q000235:genetics; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000235:genetics*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C088996:PMS1 protein, human; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins