Endometrioid uterine cancer: Histopathological risk factors of local and distant recurrence

Objectives: To determine the relationship between histopathological prognostic factors and sites of initial recurrence in endometrioid uterine cancer. Methods: A total of 355 patients (Stage I, n = 227; II, n = 38; III, n = 90) underwent primary radical surgery including complete systematic pelvic lymph node (PLN) and para-aortic lymph node (PALN) adenectomy followed by adjuvant chemotherapy who were at risk for recurrence. Relapse-free survival (RFS) and disease-related survival (DRS) were analyzed using the log-rank testing. Multivariate Cox regression analysis and logistic regression analysis were used to determine and estimate independent prognostic factors. Results: Lymph-vascular space invasion (LVSI), architectural grade (AG), myometrial invasion, and PLN metastasis (PLNM) were identified as independent prognostic factors for RFS. AG (p = 0.0043) related with local recurrence. Among patients who received adjuvant chemotherapy, patients with G3 tumor had higher ratio of recurrence (16/45) compared with G1/2 tumor (11/102) (p = 0.0004). Meanwhile, PLNM related with distant recurrence (p = 0.0008). There was a statistically significant difference in RFS according to the number of positive PLN sites (group 0: n = 313, 1: n = 16, ≥ 2: n = 26), five-year RFS in each group was 91.9%, 81.3%, and 41.2%, respectively. Conclusions: Sites of initial recurrence were related with AG and PLNM in patients with endometrioid uterine cancer. Current chemotherapy alone may not be an effective adjuvant therapy to prevent recurrence in patients with G3 tumor and ≥ 2 positive PLN sites. Prospective clinical trial needs to be conducted to establish the strategy of adjuvant therapy with these patients.