Abstract
Background
Gastric cancer is the third leading cause of cancer-related death. Determining molecular and histopathologic tumor features, which may contribute to the development or progression of gastric cancer, can improve the prognosis. Expression patterns of DNA repair proteins such as MLH1, MSH2, MSH6, and PMS2 that are associated with microsatellite instability (MSI) are some of the markers that are useful in predicting the prognosis of gastric cancer.
Purpose
The purpose was to determine the immunohistochemical expression pattern of MLH1, MSH2, MSH6, and PMS2 in tumor specimens of Iranian gastric carcinoma patients.
Methods
In this prospective cohort, 186 consecutive patients with gastric cancer, attending Taleghani Hospital, were enrolled. The immunohistochemical expression patterns of MLH1, MSH2, MSH6, and PMS2 in tumor specimens among them were determined.
Results
The results of this study demonstrated that 91.4% of our gastric cancer patients were negative for MSI, and 8.6% of them were MSI positive. The positive MSI was seen in 5.9% and 15.7% of male and female subjects, respectively, with a significant difference (P = 0.043). The other variables were not related to MSI results (P > 0.05).
Conclusion
According to the obtained results, the expression of MLH1, MSH2, MSH6, and PMS2 in tumor specimens is positive in 8.6% of the total Iranian gastric cancer sample size, which is mainly positive in female subjects. However, it is not related to the location and stage of the tumor.