Is lymph node assessment warranted in patients with endometrial intraepithelial neoplasia on an endometrial biopsy? (322)

Abstract

<b>Objectives:</b> Endometrial intraepithelial neoplasia (EIN) on endometrial biopsy is associated with a significant risk of concurrent endometrial cancer (EC) at the time of hysterectomy. This study aimed to identify clinical and pathological factors that may improve our ability to predict underlying high-grade cancer. We also sought to evaluate the justifiability and the accuracy of the sentinel lymph node (SLN) sampling as a staging procedure in this set of patients. <b>Methods:</b> A retrospective cohort study of women undergoing hysterectomy, bilateral salpingo-oophorectomy (BSO), and lymph nodes assessment for EIN on endometrial biopsy was conducted from December 2007 and August 2021. Associations between grade 2-3 carcinoma and other variables were calculated using univariable linear and multivariate regression models; covariates included age, BMI, ASA score, preoperative CA-125, and time between diagnosis and surgery. <b>Results:</b> Of the 3557 charts reviewed, 160 patients were eligible and included. Sixty patients (37.5%) were ultimately diagnosed with carcinoma. Among patients diagnosed with cancer, one patient (1.7%) was diagnosed with FIGO stage II, one patient with IIIA, and two (3.3%) were found to have positive pelvic lymph nodes (stage IIIC1). Twenty percent of the patients had FIGO grade 2-3 disease and deep myometrial invasion was present in 16.7% of the cancer samples. Total 155 patients underwent SLN with bilateral and unilateral detection rates of 93.2% and 72.9%, respectively. None of the preoperative clinical factors were found to be significantly associated with concurrent grade 2-3 endometrial cancer. <b>Conclusions:</b> Although preoperative EIN presages low-risk disease, a considerable proportion of patients are found to have high-grade disease on final pathology, which would require either re-staging surgery or adjuvant radiotherapy, which could be avoided by proper staging. Also, given its decreased perioperative morbidity, high negative predictive value, and short procedure time, assessment by SLN might still be valuable in patients with EIN on endometrial biopsy.