Low-Volume Lymph Node Metastases in Endometrial Carcinoma

Area of Science:

• Gynecologic Oncology
• Pathology
• Surgical Oncology

Background:

• Endometrial carcinoma staging relies on accurate assessment of lymph node metastases.
• Distinguishing between low-volume (isolated tumor cells, micrometastases) and high-volume (macrometastases) disease is crucial for treatment planning.
• Sentinel lymph node (SLN) biopsy is increasingly used to detect lymph node involvement.

Purpose of the Study:

• To compare the histopathologic characteristics of endometrial carcinoma patients with low-volume lymph node metastases versus macrometastases.
• To evaluate the significance of SLN dissection in identifying low-volume disease.

Main Methods:

• Retrospective review of 350 patients undergoing robotic-assisted hysterectomy for endometrial cancer.
• Analysis of sentinel lymph node (SLN) and non-SLN dissection outcomes.
• Comparison of histopathologic features (histology, grade, myometrial invasion) between groups with low-volume versus macrometastases.

Main Results:

• Among 187 patients with attempted SLN biopsy, 99% had SLN detection.
• Low-volume metastases (isolated tumor cells, micrometastases) were found in one-third of patients with nodal metastases, exclusively in those with SLN dissection.
• Patients with low-volume metastases were significantly more likely to have endometrioid histology (100% vs. 46%), Grade 1 carcinoma (58% vs. 14%), and less than 50% myometrial invasion (67% vs. 4%) compared to those with macrometastases.

Conclusions:

• Low-volume lymph node metastases in endometrial cancer are associated with favorable histopathologic features, traditionally considered low-risk.
• SLN dissection plays a key role in identifying these low-volume metastatic deposits.
• These findings support the clinical utility of SLN biopsy for precise endometrial cancer staging.