Introduction/Background We evaluate the effect of lymph-vascular space invasion on survival rate in stage I endometrial cancer (EC)

Methodology 625 patients with low-risk stage I EC were included in a prospective randomized study who underwent treatment at N.N. Alexandrov national cancer center of Belarus. After risk group determining, all patients were randomized by means of a computer program. All patients have performed hysterectomy with bilateral salpingo-oophorectomy. Groups were differed by presence or absence radiation therapy (postoperative brachytherapy).

Results In the group without lymph-vascular space invasion, the 5-year overall survival rate (OS) was 95.6% (95% CI 93.5–97.2%), cancer-specific survival rate (CSS) was 97.7% (95% CI 96.0–98.8%) disease free survival rate (DFS) was 95.9% (95% CI 93.9–97.5%). In the group with lymph-vascular space invasion, the 5-year OS was 90.2% (95% CI 83.0–95.3%), CSS - 92.0% (95% CI 85.4–96.6%), DFS 90.7% (95% CI 83.0–95.3%). Statistically significant differences in OS (p=0.019) and absence of differences in CSS (p=0.102) and DFS (p=0.144) for lymph vascular space invasion were obtained between the groups. OS and DFS were higher in the sub-group without lymph vascular space invasion on stage Ia G1 with myometrial invasion (p(OS)=0.005 and p(DFS)=0.030). There were not statistically significant differences in OS, CSS, DFS (p=0.929;; p=0.838;; p=0.802) in stage Ia G2 with myometrial invasion

Conclusion Low-risk EC represents a non-homogeneous group. The survival rate in the study group is determined by the degree of tumor differentiation and depth of myometrial invasion. The effect of lymph-vascular space invasion needs to be clarified in further studies, because of the significant effect on survival rate in stage Ia G1 EC with myometrial invasion.

Disclosure Nothing to disclose