Relationship with the frequency of MSİ (Microsatellite instability), clinicopathological features and inflammation parameters in endometrium cancer cases

Introduction: Endometrial cancer is the most common gynecological malignancy in developed countries. The discovery that the presence of MSI has a prognostic effect in colorectal cancers has paved the way for its investigation in gynecological malignancies. MSI mismatch occurs as a result of loss of function in related proteins in the presence of mutations in repair genes. Instability causes the accumulation of mutations in the cell, preventing DNA repair. We aimed to investigate the frequency of MSI, clinicopathological features and its relation with inflammation parameters in patients with endometrial cancer who applied to our clinic. Materials and Methods: This study was conducted in Afyonkarahisar Health Sciences University Medical Faculty Hospital, Medical Oncology Department between 12.12.2019-12.12.2020. 74 cases meeting the study criteria were included in the study. The information of the patients was obtained from the files available in the archive. The data of the patients were analyzed retrospectively. Paraffin blocks belonging to the tumor tissue of the patients included in the study for MSI analysis were removed from the archives of the Medical Pathology Department. Tumor paraffin tissues were subjected to various staining processes in accordance with the literature. Any nuclear staining presence was evaluated as positive and MSS. Total loss of staining in tumor cell nuclei was evaluated as negative and MSI. IBM SPSS 22.0 was used in the analysis, p <0.05 was considered statistically significant. Results: The median age of diagnosis of our patients was calculated as 61 years. Thirty (40.5%) of the cases were stage 1, 21 (28.4%) stage 2, 14 (18.9%) stage 3, and 9 (12.2%) stage 4. Microsatelled instability was detected in 21 (28.3%) of the 74 patients included in the study. Of these patients, 14 patients had mlh-1 / pms-2 (18.9%), 3 had pms-2 (4.03%), 2 had msh-2 (2.7%), 1 had msh- Expression loss of 6 / pms-2 (1.3%), 1 of them msh-2 / pms-2 (1.3%) was observed. The rates of myometrial invasion were found to be different in the groups of our patients with microsatellite instability (p = 0.008). MSI was detected in 20 (27.4%) patients with myometrial invasion, whereas MSI was not detected in any of our patients without myometrial invasion. NLR (neutrophil lymphocyte ratio), SII2 (systemic immune inflammation index) parameters were used for inflammation parameters. The distribution of NLR and SII2 values in MSI and MSS subgroups was found to be similar (p = 1,000 and p = 0,600 ). The median overall survival of our cases was found to be 17 months. Median disease-free survival was calculated as 18.5 months. The mean 5-year survival was 73% in the CNS group and 46% in the MSI group. Average survival analyzes were similar between the two groups (p = 0,760). Conclusion: We aimed to show the incidence of MSI in patients with endometrial cancer, its clinicopathological features and its relationship with inflammation parameters. We found that cases with MSI tumors were particularly associated with myometrial invasion. MSI is a possible immunotherapy candidate in cases with endometrial cancer. Therefore, it is very important to study MSI in cases with pathological diagnosis of endometrial carcinoma. For cases with endometrial cancer, more studies with multicenter prospective analysis are needed, with more cases examining MSI status and clinicopathological features.