Is universal sentinel lymph node sampling indicated in endometrial intraepithelial neoplasia (EIN)?

Incidence of endometrial carcinoma in patients with endometrial intraepithelial neoplasia versus atypical endometrial polyp

ObjectiveOur study's primary aim was to compare the incidence of endometrial carcinoma in patients with a presurgical diagnosis of endometrial intraepithelial neoplasia confined to the endometrium (EIN-E) versus endometrial intraepithelial neoplasia confined to a polyp (EIN-P). Our secondary aim was to examine the difference in pathological features, prognostic risk groups and sentinel lymph node involvement between the two groups.

METHODS

We conducted a retrospective cohort study between January 2014 and December 2020 in a tertiary university-affiliated medical center. The study considered the characteristics of women who underwent hysterectomy with sentinel lymph node dissection for endometrial intraepithelial neoplasia (EIN). We compared EIN-E diagnosed by endometrial sampling via dilatation curettage or hysteroscopic curettage vs EIN-P. A multivariate logistic regression analysis was used to assess risk factors for endometrial cancer.

RESULTS

Eighty-eight women were included in the study, of those, 50 were women with EIN-P (EIN-P group) and 38 were women with EIN following an endometrial biopsy (EIN-E group).The median age was 57.5 years (range; 52-68) in the EIN-P group as compared with 63 years (range; 53-71) in the EIN-E group (p=0.47). Eighty-nine percent of the women in the EIN-E group presented with abnormal uterine bleeding whereas 46% of the women in the EIN-P group were asymptomatic (p=0.001). Pathology results following hysterectomy revealed concurrent endometrial carcinoma in 26% of women in the EIN-P group compared with 47% of women in the EIN-E group (p=0.038). Multivariate analysis showed that endometrial cancer was significantly less common in the EIN-P group (overall response (OR)=0.3 95% confidence interval (CI)=0.1-0.9, p=0.03). Eighty-four percent of cancers were grade one in the EIN-P group compared with 50% in the EIN-E group (p=0.048).

CONCLUSIONS

Concurrent endometrial cancer is less frequent with EIN-P than with EIN-E. The high incidence of endometrial carcinoma in both groups supports the current advice to perform hysterectomy for post-menopausal women. Our data does not support performing sentinel lymph node dissection for EIN-P that was completely resected. The benefit of sentinel lymph node dissection for women with pre-operative EIN-E is yet to be determined.

Lymph node assessment at the time of hysterectomy has limited clinical utility for patients with pre-cancerous endometrial lesions

OBJECTIVE

The objective of this study was to determine the proportion of patients with a pre-invasive endometrial lesion who meet Mayo criteria for lymph node dissection on final pathology to determine if the use of sentinel lymph node biopsy in patients with pre-invasive lesions would be warranted.

METHODS

All women who underwent hysterectomy for a pre-invasive endometrial lesion (atypical hyperplasia or endometrial intra-epithelial neoplasia) between 2009 and 2019 were included for analysis. Relevant statistical tests were utilized to test the associations between patient, operative, and pathologic characteristics.

RESULTS

141 patients met inclusion criteria. 51 patients (36%) had a final diagnosis of cancer, the majority (96%) of which were Stage IA grade 1 endometrioid carcinomas. Seven patients (5%) met Mayo criteria on final pathology (one grade 3, seven size >2 cm, one >50% myoinvasive). Three of these seven patients had lymph nodes assessed of which 0% had metastases. Six of these patients had frozen section performed, and 2 met (33%) Mayo criteria intraoperatively. Of the seven patients in the overall cohort that had lymph node sampling, six had a final diagnosis of cancer and none had positive lymph nodes. Of the 51 patients with cancer, only 10 had cancer diagnosed using frozen section, and only two met intra-operative Mayo criteria. Age > 55 was predictive of meeting Mayo criteria on final pathology (p = 0.007). No patients experienced a cancer recurrence across a median follow up of 24.3 months.

CONCLUSIONS

Atypical hyperplasia and endometrial intra-epithelial neoplasia portend low risk disease and universal nodal assessment is of limited value.