Clinicopathological Implications of Mismatch Repair Status in Endometrioid Endometrial Cancer in Duhok City

DNA mismatch repair (MMR) is a specialized system that corrects errors in DNA replication, namely, base substitution mismatches and minor insertion-deletion mismatches. The deficient mismatch repair (d-MMR) protein plays a vital role in predicting the prognosis of endometrioid carcinoma. The study aimed to determine the prevalence of MMR errors in endometrial cancer (EC) and their correlation with clinicopathological features.

We examined the immunohistochemistry presence of four MMR proteins in 50 samples of EC tissues that were preserved in formalin and embedded in paraffin. The proteins identified were MutL homolog 1 (MLH1), post-meiotic segregation increased 2 (PMS2), MutS homolog 2 (MSH2), and MutS homolog 6 (MSH6). The study examined several clinicopathological characteristics and conducted MMR phenotyping.

The findings revealed that among the 50 cases of EC, 40% of patients had grade I disease and 78% had stage I malignancy. Furthermore, among the 50 individuals evaluated, 56% exhibited competence in MMR, whereas 44% displayed loss in nuclear expression of MMR. The rate of MLH1 and PMS2 protein loss was recorded as the greatest, at 18%, while the loss of MSH2 and MSH6 was documented at 6%. Within the same range, the majority of patients with d-MMR were above the age of 50 years.

The majority of the recruited EC patients in this study showed advanced age and a high percentage of d-MMR status.