Microsatellite Instability in Endometrial Adenocarcinomas of Young Women

ABSTRACT

BACKGROUND: The correlation between microsatellite instability (MSI) and the prognosis of patients with endometrial carcinomas is controversial. The endometrial carcinomas in the young adult group usually have an excellent prognosis, and these tumors might have a different frequency of MSI compared with those in old women. Further, the pathogenetic mechanisms of the two groups might be different. We investigated the frequency of MSI in the endometrial cancers of patients who were under the age of 40 and we correlated the frequency with other prognostic factors. METHODS: MSI analyses were performed using 5 primers (BAT25, BAT26, D2S123, D5S346 and D17S250) and with using the genomic DNA obtained from the paraffin embedded tumor and the paired normal tissues. RESULTS: All 23 cases we examined exhibited endometrioid adenocarcinomas, and most of them were of the low international federation of gynecologists and obstetricians (FIGO) stage (stage I 22, IIB 1); 78% were microsatellite stable and 22% were MSI-low; an abnormal peak was present at only one marker, and any case of MSI-high was not identified. The FIGO stages of the 5 MSI-low cases were variable. CONCLUSIONS: The frequency of MSI in the endometrial cancers of young patients is not significantly different from the frequencies reported for all age groups in the previous studies, MSI-low does not seem to be related to the other poor prognostic parameters, although the number of cases we studied is insufficient to draw any firm conclusion.