4 Sentinel lymph node mapping for endometrial cancer in patients with morbid obesity

Obesity is a risk factor for endometrial cancer and can increase the complexity of surgery. Previous studies have investigated sentinel lymph node (SLN) mapping in patients with a range of body mass index (BMI), with a median BMI ranging from 27–31, but have not studied success in higher BMI groups. The objective is to evaluate the success of SLN mapping in patients with BMI ≥45 compared to BMI of <45. Retrospective chart review was performed using the electronic medical records of patients who underwent robotic-assisted total laparoscopic hysterectomy with attempted SLN mapping at three institutions between January 2015 to December 2021. Patients ≥18 years old with clinical stage 1 endometrial cancer or complex atypical hyperplasia were included. Subjects were identified using ICD-9, ICD-10, and CPT codes or available cancer registries. Data collection included clinical and demographic information and outcome of SLN mapping. Data were analyzed using Stata (version 17; Stata, College Station, TX, USA). The proportion of successful SLN mapping in patients with BMI <45 versus ≥45 were compared using Chi-square test.Download : Download high-res image (61KB)Download : Download full-size image 934 patients were included: 796 (85.2%) with BMI <45, and 138 (14.8%) with BMI ≥45. Comparing the BMI <45 with the BMI ≥45 group (respectively), bilateral SLN mapping was successful in 545 (68.5%) versus 67 (48.6%); unilateral SLN mapping was successful in 159 (20.0%) versus 33 (23.9%); failed SLN mapping occurred in 92 (11.6%) versus 38 (27.5%), with a p value of <0.001. This study demonstrated that there is a statistically significant difference between the success of SLN mapping in patients with a BMI ≥45 compared to those with BMI <45. A higher proportion of patients with BMI ≥45 had failed SLN mapping and a lower rate of bilateral SLN mapping. Understanding the success of SLN mapping in patients with morbid obesity is crucial in preoperative counseling and when determining stage and intraoperative surgical management. With failed SLN mapping, alternatives include intraoperative frozen pathology for determination of need for further lymph node dissection or a full lymphadenectomy on the side that did not map. Patients with morbid obesity have a lower likelihood of successful SLN mapping which may increase their risk for full lymphadenectomy or postoperative radiation therapy with resultant sequelae.