Can systematic lymphadenectomy be omitted for low-risk endometrial cancer?

The objective of this study was to identify pathological indicators that could be used to identify a subgroup of patients with apparent stage I endometrial cancer who do require retroperitoneal lymphadenectomy. 188 T1 endometrial cancer patients underwent primary surgery at Tokushima University Hospital. We retrospectively evaluated their clinical records and histopathological factors. Systematic lymphadenectomy was performed for 149 patients, and 39 patients (grade 1 with < 5 mm of myometrial invasion) were treated without lymphadenectomy. Lymph node metastases were found in 19 (12.8%) of the lymphadenectomy cases. Twenty-four patients with a T1a endometrium-limited lesion did not exhibit lymph node metastasis. Three (3.1%) of the 95 patients with a T1a lesion exhibited lymph node metastasis, and these 3 cases exhibited approximately 50% myometrial invasion. The 39 low-risk patients who did not undergo systematic lymphadenectomy remain alive without recurrence. Systematic lymphadenectomy could be omitted for patients with a grade 1 tumor and minor myometrial invasion of less than 5mm.