Impact of DNA Mismatch Repair (MMR) in Endometrial Cancer in a Single Reference Center in Mexico.
Delia Perez Montiel, David Cantu de Leon, Armando Gamboa Dominguez, Jose Chanona Vilchis, Claudia Cavazos. Instituto Nacional de Cancerologia, Mexicio city, Mexico; Instituto Nacional de Cancerologia, Mexico city, Mexico; Instituto Nacional de la Nutricion, Mexico city, Mexico
Background: To describe DNA mismatch repair (MMR) proteins in a Mexican cohort of patients with sporadic endometrial cancer and its impact on disease-free survival and overall survival.
Design: From the cohort of patients with sporadic endometrial cancer at the Instituto Nacional de Cancerología de México charts were reviewed for clinical and pathologic characteristics. Immunohistochemistry for DNA MMR proteins MLH1, MSH2, MSH6, and PMS2 was performed on tissue microarray of primary tumors from formalin-fixed, paraffin embed blocks (3 cores per block, predominantly from areas with different grades in the same tumor). Expression of all proteins reflected intact MMR system and lack of expression of one or more proteins was considered deficient. Comparisons were made using Chi-square test. Survival curves were constructed using Kaplan-Meier method and log-rank test for comparisons.
Results: One hundred sixty-four Mexican patients were included, 131 were older than 45 years, 41 cases ( 25%) were FIGO clinical stages III/IV, 152 (93%) were obese and 87 (56%) cases had deficient DNA MMR.(25 cases with defective MSH6 only; 22 cases with defective MLH1/PMS2, 18 cases with defective MLH1/PMS2/MSH6; 18 cases with defective MLH1/PMS2/MSH2/MSH6 and 4 cases with defective MSH2/MSH6). Overall and progression-free survival were not different between patients whose tumors had intact or defective MMR; mean follow up was 27.5 months. Subgroup analyses stratified by histology (non-endometrioid versus endometrioid) showed a higher frequency of defective MMR in endometrioid carcinomas ( p=0.013) although this difference did not have impact on survival or recurrence. Others parameters as age, tumor grade, stage and P53 expression were not statistically significant.
Conclusions: Loss of DNA MMR proteins is a frequent event in sporadic endometrial cancer in Mexican population. It is also related to endometrioid histology but it does not have impact on disease-free survival or overall survival. Compared with other factors ( histopathological grading, TNM stage and FIGO classification) the status of DNA MMR continues to be controversial as a prognostic factor.
Category: Gynecologic & Obstetrics
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 160, Wednesday Afternoon