Sentinel Lymph Node Mapping in High-Grade Endometrial Cancer

A meta-analysis of the effect of pelvic and para-aortic lymph node dissection on the prognosis of patients with endometrial cancer

Endometrial cancer (EC) is the second most common malignant tumor of the female reproductive system, and it occurs in the peri- and post-menopausal periods. The metastasis routes of EC include direct spread, hematogenous metastasis and lymph node metastasis. Symptoms such as vaginal discharge or irregular vaginal bleeding may occur in the early stage. The pathological stage of the patients treated at this time is mostly in the early stage, and comprehensive treatment such as surgery, radiotherapy and chemotherapy can improve the prognosis. This article investigates whether endometrial cancer requires pelvic and para-aortic lymph node dissection. The clinical data of 228 patients with endometrial cancer who underwent pelvic lymphadenectomy in our hospital from July 2020 to September 2021 were retrospectively analyzed. All patients underwent preoperative clinical staging and postoperative pathological staging. This paper compared lymph node spread rates of endometrial carcinoma in different stages, depth of muscle invasion, and pathological characteristics to analyze lymph node metastasis risk factors. Results showed metastasis rates of 7.5% in 228 cases of endometrial cancer, increasing with deeper myometrial invasion. Different clinicopathological factors had varying lymph node spread rates. Different clinicopathological factors have different pelvic lymph node spread rates in surgical patients. The lymph node spread rate of differentially differentiated carcinoma is higher than that of well-differentiated carcinoma. The lymph node spread rate of serous carcinoma is 100%, but there is no difference between the lymph node metastasis rate of special type carcinoma and adenocarcinoma. Statistical significance (P > 0.05).

Efficacy of Single- and Dual-Docking Robotic Surgery of Paraaortic and Pelvic Lymphadenectomy in High-Risk Endometrial Cancer

(1) The surgical method of choice for the treatment of endometrial cancer is minimally invasive surgery. In cases of high-risk endometrial cancer, completed paraaortic and pelvic lymphadenectomy are indicated. The aim of this study was to analyze the types of docking during robotic surgery assisted with the da Vinci X system while performing paraaortic and pelvic lymphadenectomy. (2) Methods: A total of 25 patients with high-risk endometrial cancer, with a mean age of 60.07 ± 10.67 (range 34.69-83.23) years, and with a mean body mass index (BMI) of 28.4 ± 5.62 (range 18-41.5) kg/m2, were included in this study. The analyzed population was divided into groups that underwent single or dual docking during surgery. (3) Results: No statistical significance was observed between single and dual docking during paraaortic and pelvic lymphadenectomy and between the type of docking and the duration of the operation. However, there was a statistically significant correlation between the duration of the operation and previous surgery (p < 0.005). The number of removed lymph nodes was statistically associated with BMI (p < 0.005): 15.87 ± 6.83 and 24.5 ± 8.7 for paraaortic and pelvic lymph nodes, respectively, in cases of single docking, and 18.05 ± 7.92 and 24.88 ± 11.75 for paraaortic and pelvic lymph nodes, respectively, in cases of dual docking. (4) Conclusions: The robot-assisted approach is a good surgical method for lymphadenectomy for obese patients, and, despite the type of docking, there are no differences in the quality of surgery.

Risk factors associated with false negative rate of sentinel lymph node biopsy in endometrial cancer: a systematic review and meta-analysis

Objective

Currently, sentinel lymph node biopsy (SLNB) is increasingly used in endometrial cancer, but the rate of missed metastatic lymph nodes compared to systemic lymph node dissection has been a concern. We conducted a systematic review and meta-analysis to evaluate the false negative rate (FNR) of SLNB in patients with endometrial cancer and to explore the risk factors associated with this FNR.

Data sources

Three databases (PubMed, Embase, Web of Science) were searched from initial database build to January 2023 by two independent reviewers.

Research eligibility criteria

Studies were included if they included 10 or more women diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage I or higher endometrial cancer, the study technique used sentinel lymph node localization biopsy, and the reported outcome metrics included false negative and/or FNR.

Study appraisal and synthesis methods

Two authors independently reviewed the abstracts and full articles. The FNR and factors associated with FNR were synthesized through random-effects meta-analyses and meta-regression.

The results

We identified 62 eligible studies. The overall FNR for the 62 articles was 4% (95% CL 3-5).There was no significant difference in the FNR in patients with high-risk endometrial cancer compared to patients with low-risk endometrial cancer. There was no difference in the FNR for whether frozen sections were used intraoperatively. The type of dye used intraoperatively (indocyanine green/blue dye) were not significantly associated with the false negative rate. Cervical injection reduced the FNR compared with alternative injection techniques. Indocyanine green reduced the FNR compared with alternative Tc-99m. Postoperative pathologic ultrastaging reduced the FNR.

Conclusions

Alternative injection techniques (other than the cervix), Tc-99m dye tracer, and the absence of postoperative pathologic ultrastaging are risk factors for a high FNR in endometrial cancer patients who undergo SLNB; therefore, we should be vigilant for missed diagnosis of metastatic lymph nodes after SLNB in such populations.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023433637.

Comparison of progression-free survival outcome of sentinel node biopsy without ultrastaging versus lymphadenectomy in endometrial cancer: a propensity-matched analysis

OBJECTIVE

We aimed to investigate the oncologic outcomes of patients with endometrial cancer who underwent sentinel lymph node (SLN) biopsy without ultrastaging compared with that of those who underwent lymphadenectomy (LND).

METHODS

Patients with endometrial cancer who underwent staging with SLN biopsy or LND during 2006 - 2021 were analyzed using propensity score matching (PSM). SLN metastasis was examined using hematoxylin and eosin staining, without ultrastaging. Progression-free survival (PFS) was compared between the two groups before and after PSM using age, histology, and stage as covariates. Clinical variables such as recurrence patterns and lymphatic complications, were assessed.

RESULTS

After excluding 213 patients who underwent validation LND with SLN biopsy, 902 were identified. The demographics of the remaining patients differed according to histology, myometrial invasion depth, and stage. Lymph node metastasis was less frequent in the SLN group than in the LND group (9.4% vs. 3.8%, p=0.004). The recurrence rates within 2 years were lower in the SLN group. The SLN group exhibited significantly superior 2-year and overall PFS than the LND group. Among patients with uterus-confined disease, overall PFS was favorable for SLN biopsy. After matching, differences in PFS were no longer observed, although the lymphocele and lymphedema rates were significantly lower in the SLN group.

CONCLUSION

In patients with endometrial cancer, SLN biopsy without ultrastaging did not compromise survival outcomes and was associated with significantly reduced lymphatic complication rates compared with LND. Therefore, SLN biopsy can be recommended for patients with endometrial cancer without definitive preoperative evidence of distant metastasis.

Applications and Safety of Sentinel Lymph Node Biopsy in Endometrial Cancer

Lymph node status is important in predicting the prognosis and guiding adjuvant treatment in endometrial cancer. However, previous studies showed that systematic lymphadenectomy conferred no therapeutic values in clinically early-stage endometrial cancer but might lead to substantial morbidity and impact on the quality of life of the patients. The sentinel lymph node is the first lymph node that tumor cells drain to, and sentinel lymph node biopsy has emerged as an acceptable alternative to full lymphadenectomy in both low-risk and high-risk endometrial cancer. Evidence has demonstrated a high detection rate, sensitivity and negative predictive value of sentinel lymph node biopsy. It can also reduce surgical morbidity and improve the detection of lymph node metastases compared with systematic lymphadenectomy. This review summarizes the current techniques of sentinel lymph node mapping, the applications and oncological outcomes of sentinel lymph node biopsy in low-risk and high-risk endometrial cancer, and the management of isolated tumor cells in sentinel lymph nodes. We also illustrate a revised sentinel lymph node biopsy algorithm and advocate to repeat the tracer injection and explore the presacral and paraaortic areas if sentinel lymph nodes are not found in the hemipelvis.

Therapeutic Benefit of Systematic Lymphadenectomy in Node-Negative Uterine-Confined Endometrioid Endometrial Carcinoma: Omission of Adjuvant Therapy

Simple Summary

Endometrial cancer is the most common gynecological tract malignancy in developed countries. Extrauterine disease, in particular lymph node metastasis, is an important prognostic factor. Nevertheless, pelvic lymphadenectomy is not considered to have a therapeutic benefit, as it did not improve survival in randomized studies. However, lymphadenectomy may have a therapeutic benefit if adjuvant therapy can be omitted without decreasing oncological outcomes, as the long-term quality of life is maintained by avoiding morbidities associated with adjuvant therapy. In intermediate- and high-risk endometrioid endometrial carcinomas, adjuvant therapy may be safely omitted without decreasing long-term survival by open surgery including systematic pelvic and para-aortic lymphadenectomy when patients are node-negative. Systematic lymphadenectomy may remove undetectable low-volume lymph node metastasis in both pelvic and para-aortic regions, and open surgery may reduce vaginal recurrence even without vaginal brachytherapy. However, lymphadenectomy may not improve survival in elderly patients and patients with p53-mutant tumors.

Abstract

Endometrial cancer is the most common gynecological tract malignancy in developed countries, and its incidence has been increasing globally with rising obesity rates and longer life expectancy. In endometrial cancer, extrauterine disease, in particular lymph node metastasis, is an important prognostic factor. Nevertheless, pelvic lymphadenectomy is not considered to have a therapeutic benefit, as it did not improve survival in randomized studies. However, lymphadenectomy may have a therapeutic benefit if adjuvant therapy can be omitted without decreasing oncological outcomes, as the long-term quality of life is maintained by avoiding morbidities associated with adjuvant therapy. In intermediate- and high-risk endometrioid endometrial carcinomas, adjuvant therapy may be safely omitted without decreasing long-term survival by open surgery including systematic pelvic and para-aortic lymphadenectomy when patients are node-negative. Systematic lymphadenectomy may remove undetectable low-volume lymph node metastasis in both pelvic and para-aortic regions, and open surgery may reduce vaginal recurrence even without vaginal brachytherapy. However, lymphadenectomy may not improve survival in elderly patients and patients with p53-mutant tumors. In this review, I discuss the characteristics of lymph node metastasis, the methods of lymph node assessment, and the therapeutic benefits of systematic lymphadenectomy in patients with intermediate- and high-risk endometrioid endometrial carcinoma.