Impact of incorporating an algorithm that utilizes sentinel lymph node mapping during minimally invasive procedures on the detection of stage IIIC endometrial cancer

Objective: To determine whether the frequency of cases diagnosed with stage IIIC endometrial cancer is affected by the incorporation of a modified surgical lymph node assessment.

Methods: Since 2008, we have increasingly utilized a modified nodal assessment using an algorithm that incorporates SLN mapping. For this analysis, we identified all cases of newly diagnosed endometrial cancers undergoing a minimally invasive staging procedure not requiring conversion to laparotomy from 1/1/08 to 12/31/10. Procedures were categorized as standard, modified, and hysterectomy only. Differences were based on time period: 2008 (Y1), 2009 (Y2), and 2010 (Y3). Appropriate statistical tests were used.

Results: We identified a total of 507 cases. The distribution of cases was 143 (Y1), 190 (Y2), and 174 (Y3). Tumor grade (P=0.05) and high-risk histologies (P=0.8) did not differ during the 3 time periods. A standard staging procedure was performed in the following cases: Y1 (93/143; 65%), Y2 (66/166; 35%), and Y3 (40/164; 23%) (P<0.001). Median operative times were as follows: Y1 (218 min), Y2 (198 min), and Y3 (176.5 min) (P<0.001). The median numbers of total lymph nodes removed among cases with at least 1 node retrieved were: Y1 (20); Y2 (10); Y3 (7) (P<0.001). Cases diagnosed as stage IIIC were as follows: Y1 (10/143; 7%), Y2 (15/166; 7.9%), and Y3 (13/164; 7.5%) (P=1.0).

Conclusions: The incorporation of a modified staging approach utilizing the SLN mapping algorithm reduces the need for standard lymphadenectomy and does not appear to adversely affect the rate of stage IIIC detection.