Prognostic Significance of “High” Tumor Budding and “High” Poorly Differentiated Clusters in Endometrial Carcinomas: Independent Predictors of Lymphovascular Space Invasion and Lymph Node Metastasis

Tumor budding (TB) and poorly differentiated clusters (PDCs) are well-established prognostic factors in various cancers. This study aimed to assess the independent prognostic role of these markers in endometrial carcinomas. Retrospective analysis of endometrial carcinoma resection specimens by examining traditional histologic prognostic parameters. TB and PDC were observed at 20× magnification in ten fields at the invasive front and categorized as present or absent. In addition, a count of ≥5 was stratified as “high.” Clinical and follow-up details were extracted from Gynecologic Oncology records. Sixty-five endometrial carcinomas were studied and were predominantly endometrioid (n=47, 72.3%). TB was identified in 52.3% of cases, with high TB observed in 38.5%. PDC was evident in 44.6%, with high PDC seen in 29.2%. Associations were significant between the presence of TB/high TB and higher tumor grade ( P < 0.001), deep myometrial invasion ( P = 0.006/ P = 0.002), diffuse pattern of invasion ( P = 0.007/ P = 0.03), microcystic elongated and fragmented pattern ( P < 0.001), lymphovascular space invasion, lymph node metastasis ( P =<0.001) and International Federation of Gynecology and Obstetrics stage ( P = 0.000/ P = 0.002). PDC/high PDC showed similar associations, and, in addition, with nonendometrioid histologic type ( P = 0.02) and tumor location in a lower uterine segment (high PDC, P = 0.009). After adjusting for other significant parameters, both high TB ( P = 0.03) and high PDC ( P = 0.031) emerged as independent prognostic parameters for lymphovascular space invasion or Lymph node metastasis. No recorded deaths or significant events occurred, precluding commentary on overall survival status. High TB and PDC are independent predictors of Lymph node metastasis in endometrial carcinomas. Their association with the microcystic elongated and fragmented pattern makes them histologic predictors of epithelial-mesenchymal transition. Their simple application underscores their potential as valuable additional prognostic indicators for endometrial carcinomas.