Objectives To explore the risk factors of para-aortic lymph node (PALN) metastasis in endometrial carcinoma.

Methods 514 cases with comprehensive staging surgery were included. The risk factors of para-aortic lymphatic metastasis were analyzed with SPSS 23.0 and R software and a meta-analysis was performed.

Results 79 cases had pelvic lymph nodes (PVLN) metastasis, 59 PALN metastasis, and 21 cases were PALN metastasis without PVLN metastasis. The ratio PVLN metastasis and PALN metastasis were 1.9% and 0.9% in low-risk group, 14.9% and 11.4% in intermediate-risk group, 23.8% and 18.3% in high-risk group, respectively. Almost all factors increased the risk of PALN metastasis except age and stage. The PVLN metastasis was the top one risk factor of PALN metastasis, lymphovascular space invasion (LVSI) and tumor diameter (TSIZE) ranked the top 2 and 3. The multivariate logistic regression model showed that, PVLN metastasis was the most relative factor of PALN metastasis with the OR of 7.21. Cervical stromal invasion (CI) and TSIZE followed it. The meta-analysis we did with published references from 1988 to 2017 in the database showed that adnexal involvement, cervical stromal invasion, peritoneal cytology positive, LVSI positive and PVLN positive were risk factors of PALN metastasis.

Conclusions Adnexal involvement, deep myometrium invasion, peritoneal cytology positive, CI, TSIZE, LVSI positive and PVLN positive increased the risk of PALN metastatic. Our data indicated CI, TSIZE, LVSI positive, PVLN positive were the top 4 risk factors of PALN metastatic, especially PVLN positive. We commend PALN dissection should be performed for those who have the high-risk factors mentioned above.