Tumor diameter as a predictor of lymph node involvement in endometrioid type endometrial adenocarcinomas.

Aim: To analyze the risk factors of lymph node involvement in pure endometrioid type endometrial cancer and assess factors that necessitate lymphadenectomy.
Methods: Patients who had been operated on due to endometrial cancer and whose final pathology was reported as pure endometrioid carcinoma between January 2014 and January 2020 were assessed. Hysterectomy, bilateral salpingo-oophorectomy, and systematic lymphadenectomy were performed in all patients. All specimens were reported by expert gynecopathologists.
Results: The lymph node positivity rate was 14.4%. When the study population was classified according to the Mayo risk criteria; lymph node involvement in the low-risk and high-risk groups was 9.1% and 14.8%, respectively and there was no statistically difference (p > 0.05). The median of tumor size and the rate of deep myometrial invasion, lymphovascular space invasion, adnexal involvement, FIGO grade 3 tumor were found significantly higher in the positive lymph node group in univariate analysis. In the receiver operating characteristic curve analysis, the cut-off value of the tumor diameter was determined as 47.5 mm (sensitivity 85%, specificity 62%). Every 10 mm increase in tumor diameter increased the risk of lymph node involvement 10 times.
Conclusion: This study defined that the tumor diameter is an independent predictor for lymphatic dissemination. In the future, it could be shown that even with new modeling based on tumor diameter, lymphadenectomy or adjuvant radiotherapy requirements would be reevaluated.
(© 2021 Japan Society of Obstetrics and Gynecology.)