Predictability of lymph node involvement in uterus-confined endometrioid endometrial cancer by tumour size, pattern and location measured with transvaginal ultrasonography: can we save time?

We aimed to investigate whether transvaginal ultrasonography (TVUSG)-measured tumour size, pattern and location were significant predictors for lymph node metastasis in the uterus-confined endometrioid endometrial cancer (EEC) patients. A total of 213 patients with EEC were recruited and 73 of them were considered eligible and were analysed according to lymph node involvement. Tumour size, pattern and location measured by transvaginal ultrasound were recorded. Thereafter, patients were distributed according to their lymph node involvement and were compared with respect to these parameters. The patients' median age was 56 (27-80). Mean of the resected lymph nodes was 29.68 and 33.5 in lymph-node-negative and positive patients, respectively (p=.525). Tumour diameter was measured >2 cm on transvaginal ultrasound in 28 (48.3%) and 13 (86.7%) cases of the lymph node-negative and positive arms, respectively (p=.008). Transvaginal ultrasound revealed that 18 (31.0%) tumours in lymph node-negative and two (13.3%) in the node positive patients had polypoid pattern (p=.171). Seventeen (54.8%) tumours of the lymph node-negative group and three (42.9%) of the node positive group were determined in the lower uterine segment (p=.250). While tumour diameter measured with TVUSG was predictable for lymph node involvement in the uterus-confined EEC, its pattern and location were not.Impact Statement What is already known on this subject? In clinically early-stage endometrioid endometrial cancer (EEC), it has been recognised for decades that selective lymphadenectomy is a more acceptable strategy than the systematic lymphadenectomy, owing to the low rate of lymph node metastases in the patients. Preoperative imaging, frozen section and recently accepted lymph node concept are the prominent methods in designating appropriate candidates for lymphadenectomy. The measurement of tumour diameter or size obtained intraoperatively by frozen section assessment is one of the parameters used in MAYO criteria for selective lymphadenectomy in endometrial cancer patients. What do the results of this study add? In our study, tumour diameter measured with transvaginal ultrasonography was predictable for lymph node involvement in the uterus-confined EEC. What are the implications of these findings for clinical practice and/or further research? Transvaginal ultrasonography-measured tumour diameter can be considered in deciding to proceed with pelvic lymphadenectomy while waiting for the frozen section result. It should be remembered that this approach could be considered only in clinics using MAYO criteria for selective lymphadenectomy, and it needs to be confirmed with more prospective studies.