Risk assessment of extra-uterine involvement and prognosis in young type I endometrial carcinoma with high or moderate differentiation and less than 1/2 myometrial invasion

Purpose: The aim of this study was to investigate whether young patients with endometrial carcinoma can preserve adnexa and lymph nodes to improve their quality of life without compromising their prognosis. Methods: A total of 319 patients with type I endometrial carcinoma (high or moderate differentiation and less than 1/2 myometrial invasion) hospitalized in the First Affiliated Hospital of Zhengzhou University from May 2012 to July 2021 were included. The patients were divided into four groups: high differentiation without myometrial invasion group (G1MI-), high differentiation with superficial myometrial invasion group (G1MI+), moderate differentiation without myometrial invasion group (G2MI-), and moderate differentiation with superficial myometrial invasion group (G2MI+). Logistic regression analysis was conducted to identify risk factors for extra-uterine involvement. Kaplan-Meier method was used to draw the survival curve to compare the prognosis in subgroups and rates of extra-uterine involvement were also compared using Chi-square test or Fisher’s exact test. Results: Multivariable logistic regression revealed that differentiation (HR = 14.590, 95%CI = 1.778-119.754, p = 0.013) and myometrial invasion (HR = 10.732, 95%CI = 0.912-92.780, p = 0.037) were the independent risk factors for extra-uterine involvement. The overall difference was statistically significant (p < 0.001). In the subgroups analysis, both adnexal metastasis and lymph node metastasis were statistically significant in the G2MI+ group compared with G1MI- (p = 0.007, p = 0.008). There were no significant differences in the overall survival (OS) rate and progression free survival (PFS) rate among the four subgroups (p > 0.05). Conclusions: Surgery with adnexal preservation and without systematic lymphadenectomy could be employed for the patients who are high differentiation with less than 1/2 myometrial invasion or moderate differentiation without myometrial invasion, but not recommended to the patients with moderate differentiation and superficial myometrial invasion.