Risk factors for paraaortic lymph node metastasis in endometrial cancer.

Objective: The purpose of this study was to determine the risk factors for paraaortic lymph node (LN) metastasis in endometrial cancer (EC) patients who underwent comprehensive surgical staging.

Methods: A total of 641 women with EC (endometrioid, non-endometrioid, or mixed histology) who underwent comprehensive surgical staging including pelvic and paraaortic LN dissection between 2008 and 2016 were included in this retrospective study. Patient data were analyzed with respect to paraaortic LN involvement, and predictive factors for paraaortic LN metastasis were investigated.

Results: Lymph node metastasis was detected in 90 (14%) patients, isolated pelvic LN metastasis in 28 (4.3%), isolated paraaortic LN metastasis in 15 (2.3%), and both pelvic and paraaortic LN metastasis in 47 (7.3%) women, respectively. Univariate analysis showed that the risk of paraaortic LN metastasis significantly increased in patients with non-endometrioid histology, age greater than 60 years, grade 3 tumor, deep myometrial invasion, lymphovascular space invasion (LVSI), primary tumor diameter (≥2 cm), cervical stromal invasion, adnexal involvement, serosal invasion, pelvic LN involvement, two or more positive pelvic LNs, and positive peritoneal cytology (p < 0.05). At the end of multivariate analysis, the presence of LVSI [odds ratio (OR), 4.8; 95% confidence interval (CI), 1.25-18.2; p = 0.022] and pelvic LN metastasis (OR, 18.8; 95% CI, 5.7-61.6; p < 0.001) remained as independent risk factors for paraaortic LN involvement in women with EC.

Conclusion: The presence of LVSI and pelvic LN involvement appear to be independent risk factors for paraaortic LN metastasis in patients with EC. LVSI may be considered as a routine pathological parameter during frozen section analysis in women with EC undergoing surgery.