Prior research has examined sentinel lymph node (SLN) mapping among patients with a range of BMI values (median BMI range, 27-31), but no studies have examined mapping success among individuals with higher BMI. To investigate this, Nicole Fennimore, MD, and colleagues conducted a retrospective chart review using EMR data for adult patients with stage 1 endometrial cancer (EC) who had robotic-assisted total laparoscopic hysterectomy with attempted SLN mapping at three institutions between January 2015 and April 2020.

Success of SLN Mapping Varied by BMI Group

Among 702 patients included in the study, most patients (N=598; 85%) had a BMI of less than 45. Fewer than 100 patients (N=104; 15%) had a BMI of equal to or greater than 45.

When the researchers compared patients according to BMI grouping (<45 vs ≥45), bilateral SLN mapping was successful in 398 patients (66.56%) versus 47 patients (45.19%), respectively. Unilateral SLN mapping was successful in 131 patients (21.91%) versus 25 patients (24.04%), and failed SLN mapping was reported in 69 patients (11.54%) versus 32 patients (30.77%), with a P value of less than 0.001.

Impact of Morbid Obesity in Counseling and Treatment

The findings indicate a statistically significant difference in the success of SLN mapping among patients with a BMI of greater than or equal to 45 compared with patients with a BMI of less than 45. Specifically, the preliminary data from this study indicate that patients with morbid obesity experience a decreased likelihood of successful SLN mapping, potentially increasing their risk for full lymphadenectomy or postoperative radiation therapy with resultant sequelae. According to the researchers, understanding the impact of morbid obesity in success rates with SLN mapping are important for counseling and managing patients with EC, particularly in regard to identifying disease stage and intraoperative surgical management.