Blood Vessel Invasion Is a Strong Predictor of Postoperative Recurrence in Endometrial Cancer.

OBJECTIVES: Although lymphovascular space invasion is a prognostic factor for the recurrence of resectable endometrial cancer, the differential impacts of lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) on the recurrence of endometrial cancer are poorly described. We investigated the prognostic significance of LVI and BVI on the recurrence of endometrial cancer and their association with patterns of recurrence. METHODS: We retrospectively reviewed 376 patients with stage I to III endometrial cancer who underwent surgery with curative intent at our institution between 2007 and 2015. The associations of the presence of lymphovascular space invasion or LVI and BVI with recurrence-free survival and patterns of recurrence were evaluated. RESULTS: Lymphovascular space invasion positivity was an independent prognostic factor for recurrence-free survival (hazards ratio [HR], 3.070; 95% confidence interval [CI], 1.404-6.824; P = 0.0048). However, when categorized by LVI versus BVI, the latter was a strong independent prognostic factor (HR, 2.697; CI, 1.288-5.798; P = 0.0081), whereas the former was not (HR, 1.740; CI, 0.795-3.721; P = 0.1637). Hematogenous metastasis was the most prevalent form of recurrence in endometrial cancer (24 [50%] of all 48 recurrent cases). Notably, 17 (19.5%) of 87 patients with BVI developed hematogenous metastases, compared with 7 (2.4%) of 289 without BVI (χ test, P < 0.0001). CONCLUSIONS: Blood vessel invasion rather than LVI was a strong predictor of postoperative recurrence in stage I to III endometrial cancer, probably due to its predisposition to hematogenous metastases.