Prognostic value of Ki-67 in patients with endometrial cancer in the Republic of Moldova

Abstract

Introduction/Background: Endometrial adenocarcinoma is characterized by a good prognosis. According to the National Cancer Registry of the Republic of Moldova, endometrial cancer has shown a rising trend in morbidity over the past five years. In 2024, 515 new cases were reported, with 92 deaths. Notably, over 77% of cases are diagnosed in early stages (I–II), which correlates with favorable 5-year survival rates—up to 95% in stage IA. However, survival decreases with advancing stage: 65–80% in stage IB and just over 50% in stage II. Treatment of endometrial cancer (EC) is still based on clinico-pathological parameters, which have limited role in risk stratification. There is a need for more determinant markers, such as Ki-67, to identify patients at higher risk of relapse. Methodology: 50 patients with EC were involved in this prospective study. The patients were treated and followed up at Institute Of Oncology of Moldova. Ki-67 was detected by immuno-histochemical exam and compared with other clinico-pathological criteria. Survival was assessed and compared by Kaplan-Meier curves. Results: Ki-67expression more than 49% was detected in 17 patients (22.4%). This analysis highlights the prognostic relevance of clinicopathological features and Ki-67 expression in stage I–II of EC. High differentiation grade and low Ki-67 index (<49%) are strongly associated with low-risk profiles, while low-grade tumors and elevated Ki-67 (>49%) correlate with high-risk groups. Deep myometrial invasion (>50%) and advanced disease stages (IB–II) significantly align with increased Ki-67 and higher risk categories. Although endometrioid histology predominates across all groups, non-endometrioid subtypes are more frequent in high-risk cases and were significantly associated with shorter Disease-Free Survival (DFS) but no significant correlation was detected between Ki-67 and DFS. Conclusion: Our study indicates that Ki-67 is significantly associated with poor tumour characteristics and shorter disease-free survival and may be a helpful tool as a part of a simple clinical molecular classification for EC.