Clinical characteristics of endometrial cancers with microsatellite instability-high and BRCA1/2 mutations

The purpose of this study was to identify the clinical features of endometrial cancers (EC) with microsatellite instability-high (MSI-H) and BRCA1/2 mutations (BRCAm).

We selected patients diagnosed with EC who were MSI-H from the Affiliated Hospital of Qingdao University between March 2021 and December 2024. The clinical information was collected after applying the inclusion and exclusion criteria. Based on BRCA1/2 status, we divided the patients into two groups: the MSI-H only group (M group), and the MSI-H and BRCAm group (MB group). After comparing the clinical characteristics of the two groups, Kaplan-Meier (K-M) curves were employed to analyze the distribution of progression-free survival (PFS) between them. Finally, both univariate and multivariate Cox proportional hazards regression models were utilized to assess various prognostic variables.

A total of 177 patients were included in the final analysis, of whom 28 were identified as having BRCAm. The rate of laparoscopic surgery in M group was higher than that in MB group (87.25% vs. 67.86%, p-value=0.022). The lymph node metastasis rate in MB group was significantly higher than that in M group (14.29% vs. 2.01%, p-value=0.011). Additionally, a higher proportion of patients received immunotherapy in MB group (7.14% vs. 2.68%, p-value=0.011). The recurrence rates in M group and MB group were 1.34% and 17.86%, respectively (p-value=0.003). K-M analysis indicated that there was statistically significant difference in PFS between the two groups (p-value=0.006). Furthermore, we did not identify any independent risk factors that influenced prognosis in our study.

The co-occurrence of BRCAm and MSI-H is associated with high rates of lymph node metastasis and recurrence. However, BRCAm was not an independent prognostic factor influencing PFS of EC with MSI-H.