Introduction/Background Endometrial intraepithelial neoplasia (EIN) is a precursor of endometrial carcinoma (EC),the role of lymph node (LN) is highly controversial.

In view of the risk for occult carcinoma, the option of adjuvant treatment decision, and the low morbidity of sentinel lymph node (SLN), some are considering performing SLN in EIN to avoid ’re-staging’ or inappropriate adjuvant treatment, either over or under-treatment.

Since SLN might be more complex in patients with elevated BMI,as previously reported in EC, we sought to evaluate the effect of BMI on the SLN detection rate (DR) during robotic hysterectomy in EIN cases.

Methodology A retrospective chart review, encompassing all patients with pre-operative diagnosis of EIN who underwent robotic surgical staging including SLN sampling.

For the analysis, five BMI subgroups were determined according to literature (<24.9,25–29.9,30–34.9,35–39.9,>40).

Distribution normality was assessed using Kolmogorov Smirnov test. 2-sided Student’s t-tests were used to compare continuous variables,Mann-Whitney U-test for non-parametric continuous variables and chi-squared test for categorical variables. Multinomial logistic regression was used for categorical clinical outcomes. A probability value of <0.05 was considered statistically significant.

Results A total of 115 patients with EIN were included in our study with an average BMI of 34.75±9.38 SD.

A chi-square test comparing 5 different BMI sub-groups showed no significant difference in SLN DR between the groups (p=0.606). Moreover, no significant difference was found when examining specific high BMI sub-groups: obesity with BMI >30(N=74,DR=68.9%, p=0.181), morbid obesity with BMI>40 (N=37,DR=67.6%,p=0.362).

Furthermore, to investigate whether an elevation of a BMI unit will reduce the SLN DR, a logistic regression model was performed. The model showed that for every unit of BMI the likelihood of SLN DR did not change significantly (adjusted odds ratio=0.98, 95% CI 0.94–1.02,p=0.321).

Using the same statistical methods for the analysis of unilateral DR, we found no significant difference when comparing the 5 different BMI sub-groups (p=0.269). Similarly,no significant difference was found when examining the high BMI sub-groups:

BMI>30(DR=85.1%,p=0.053),BMI>40(DR=83.8%,p=0.162).

Conclusion We found no connection between obesity(BMI>30) or morbid obesity (BMI>40) and reduced SLN DR in EIN cases, nor a significant variation in the DR when comparing all the different BMI subgroups.

Disclosures No.