Lymphatic mapping in endometrial cancer: a literature review of current techniques and results

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.

Sentinel lymph node biopsy in endometrial cancer: state of the art

Endometrial cancer (EC) is the most common gynecological neoplasm in developed countries. In literature, there are discordant data regarding the therapeutic value of systematic lymphadenectomy whereas the importance of lymph node status for determining prognosis and the need for adjuvant treatment is undoubted. Given the low risk of lymph-node metastases in the apparent early-stage disease and the significant surgical and postoperative risks when performing a complete pelvic lymphadenectomy, the surgical approach in these patients is controversial, ranging from no nodal evaluation to comprehensive pelvic and aortic lymphadenectomy. The recent introduction of sentinel node mapping represents the mid-way between the execution and omission of node dissection in EC patients. Indeed, the sentinel node mapping has rapidly emerged as an alternative to complete lymphadenectomy to reduce morbidity. In the present review, we discuss the role of sentinel node mapping in the surgical management of EC evaluating all aspects of this procedure.

Where Are We Going with Sentinel Lymph Node Mapping in Gynecologic Cancers?

PURPOSE OF REVIEW

Sentinel lymph node (SLN) mapping is a standard of care for lymphatic assessment of many early-stage gynecologic malignancies. We review the current data, emphasizing the utility of SLN mapping in the management of gynecologic cancers.

RECENT FINDINGS

Endometrial cancer: recent studies have focused on confirming the safety and efficacy of SLN mapping for high-risk patients. Cervical cancer: the LACC Trial demonstrated reduced survival with minimally invasive surgery, calling into question the validity of prior studies evaluating SLN mapping with a minimally invasive approach. Vulvar cancer: the ongoing GROINS-V-II trial is investigating whether patients with SLN metastasis < 2 mm in diameter can safely undergo adjuvant radiation ± chemotherapy without completion inguinal lymphadenectomy. NCCN guidelines have incorporated SLN mapping as a lymphatic assessment strategy for endometrial, cervical, and vulvar malignancies. SLN mapping appears to reduce morbidity while still maintaining an appropriate detection rate of lymphatic metastasis. Additional clinical trials will further our knowledge of these procedures.

A prospective evaluation of the sentinel node mapping algorithm in endometrial cancer and correlation of its performance against endometrial cancer risk subtypes

OBJECTIVE

Sentinel node mapping is emerging as the alternative to lymphadenectomy in endometrial cancer. The objective of our study is to validate of the sentinel node mapping surgical algorithm and also to compare the performance of the algorithm against endometrial cancer risk subtypes DESIGN: This is a prospective interventional study carried out at a Single University teaching hospital. All patients with apparent early stage endometrial cancer who underwent robotic assisted surgical staging were included. Intracervical injection of Indocyanine Green dye and sentinel node identification and biopsy was done for all study patients. The node positive rate when using SLN mapping alone versus SLN mapping algorithm were compared. The node positivity was compared against various risk subtypes of endometrial cancer.

RESULTS

69 patients were included in the study. In 95.7% patients SLN was detected with a bilateral detection rate of 87.9%. 10 patients had nodal positivity, among which 7 were identified by SLN mapping alone. The algorithm captured all 10 patients with positive LNs, yielding a node positivity rate of 14.9%, sensitivity and NPV of 100%. For SLN mapping alone the sensitivity was 77.8%, false negative rate (FNR) 22.2%, and NPV 96.6%. In low- and intermediate-risk subtypes SLN mapping as well as algorithm identified all node positive patients, but in high-risk endometrial cancers the SLN mapping technique alone had a sensitivity of 57.1% and false-negative rate of 42.9% when compared with 100% sensitivity for the SLN mapping algorithm.

CONCLUSIONS

When doing SLN mapping and biopsy during endometrial cancer staging surgery it is essential that the steps mentioned in the SLN mapping algorithm are followed as SLN mapping alone seems to have a limitation in detecting positive nodes especially in high risk subtypes of endometrial cancer. Even with the lack of survival data, based on the performance of SLN mapping surgical algorithm (even if ultrastaging facility is not available), it seems to be a better technique in detecting metastatic nodes, giving prognostic information, and enabling accurate adjuvant treatment.

Sentinel lymph node mapping in gynecological oncology

The intraoperative mapping of sentinel lymph nodes (SLNs) is part of the treatment strategy for a number of types of tumor. To retrospectively compare results from the mapping of pelvic SLNs for gynecological oncology, using distinct dyes, the present review was conducted to determine the clinical significance of SLN mapping for gynecological oncology. In addition, the present study aimed at identifying an improved choice for SLN mapping tracers in clinical application. Each dye exhibits demerits when applied in the clinical environment. The combination of radioisotopes and blue dyes was identified to exhibit the most accurate detection rate of SLN drainage of gynecological oncology. However, contrast agents were unable to identify whether a SLN is positive or negative for metastasis prior to pathologic examination; additional studies are required.

Unexpected locations of sentinel lymph nodes in endometrial cancer

INTRODUCTION

To evaluate the anatomical location of sentinel lymph nodes (SLN) following intra-operative cervical injection in endometrial cancer.

METHODS

All consecutive patients with endometrial cancer undergoing sentinel lymph node mapping were included in this prospective study following intra-operative cervical injection of tracers. Areas of SLN detection distribution were mapped.

RESULTS

Among 436 patients undergoing SLN mapping, there were 1095 SLNs removed, and 7.9% of these SLNs found in 13.1% of patients, were detected in areas not routinely harvested during a standard lymph node dissection. These included the internal iliac vein, parametrial, and pre-sacral areas. The SLN was the only positive node in 46.1% (15/36) of cases with successful mapping and completion lymphadenectomy, including 3 cases where the sentinel node in the atypical location was the only node with metastatic disease.

CONCLUSION

SLN mapping using intra-operative cervical injection is capable to map out areas not typically included in a standard lymphadenectomy. The sentinel node is the most relevant lymph node to analyze and may enable to discover metastatic disease in unusual areas.

Survival of Patients with Serous Uterine Carcinoma Undergoing Sentinel Lymph Node Mapping

OBJECTIVE

The aim of this study was to determine progression-free survival (PFS) in patients with serous uterine carcinoma undergoing sentinel lymph node (SLN) mapping compared with patients undergoing standard lymphadenectomy.

METHODS

We retrospectively reviewed all uterine cancer patients treated at our institution from 2005 to 2015. Patients were separated into two cohorts: those who underwent SLN mapping at the time of staging (SLN) and those who underwent routine lymphadenectomy (the non-SLN group). SLN mapping was performed according to institutional protocol, incorporating a surgical algorithm and pathologic ultrastaging.

RESULTS

Overall, 248 patients were identified-153 SLN mappings and 95 routine lymphadenectomies (pelvic and/or paraaortic lymph node dissection). No significant difference in age or body mass index was observed between the groups (p = 0.08 and p = 0.9, respectively). Minimally invasive surgery was utilized in 117/153 (77%) SLN patients and 30/95 (32%) non-SLN patients (p = <0.001). Stage distribution for the SLN and non-SLN cohorts demonstrated 106/153 (69%) and 59/95 (62%) patients with stage I/II disease, respectively, and 47/153 (31%) and 36/95 (38%) patients with stage III/IV disease, respectively (p = 0.3). The median number of nodes removed was 12 (range, 1-50) in the SLN cohort versus 21 (range, 1-75) in the non-SLN cohort (p = <0.001). Adjuvant chemotherapy alone or with radiation therapy was administered in 122/153 (80%) SLN patients and 79/95 (83%) non-SLN patients; radiotherapy alone was administered in 12/153 (8%) SLN patients and 7/95 (7%) non-SLN patients (p = 0.8). At a median follow-up of 40 months, the 2-year PFS rates were 77% (95% confidence interval [CI], 68-83%) in the SLN group and 71% (95% CI, 61-79%) in the non-SLN group (p = 0.3).

CONCLUSIONS

Incorporation of the SLN mapping algorithm into the staging of uterine serous cancer is feasible and does not appear to compromise prognosis. PFS in patients with uterine serous carcinoma undergoing SLN mapping, followed by adjuvant therapy, was similar to PFS in patients undergoing standard lymphadenectomy and adjuvant therapy.

Sentinel Lymph Node Mapping in Endometrial Cancer: An Update

: Lymph node removal for staging, as part of the initial surgical management of patients with endometrial carcinoma, remains a controversial topic in gynecologic oncology. There is currently wide variability among clinical practices, with surgical approaches ranging from no nodal evaluation to comprehensive pelvic and aortic lymphadenectomy. Lymphatic mapping has emerged as an increasingly popular option over the past few years, with several attractive features in its concept, innovative surgical approach, and encouraging preliminary results. At this time, however, several different techniques have been described and used for lymphatic mapping in endometrial cancer, incorporating a variety of mapping agents and injection sites. Although recently published results are encouraging, they are limited to single-institution series or multi-institutional collaborations undertaken without the aegis of a prospective randomized controlled trial. However, the surgical staging of endometrial cancer with lymphadenectomy was historically established based not on randomized trial data but on prospective clinicopathologic studies. Another evolving field in endometrial cancer staging is the interpretation of pathologic ultrastaging of sentinel lymph nodes (SLNs), which can identify low-volume metastases for which the clinical significance and the ideal management remain uncertain. This is particularly an issue with extremely low-volume nodal metastasis and isolated tumor cells. Furthermore, it has become apparent that applying a predefined SLN algorithm can decrease false-negative rates. The Memorial Sloan Kettering Cancer Center SLN algorithm can be used as a checklist to ensure standardization of care and to reduce the chance of missing nodal disease. Prospective trials are under way at many institutions to help establish the definitive role of SLN mapping for staging of endometrial cancer. The objective of this study was to provide an update on the latest clinical data related to lymphatic mapping for the staging and management of endometrial cancer and its role in clinical practice.

IMPLICATIONS FOR PRACTICE

Lymphatic mapping is an increasingly popular option in the surgical treatment of endometrial cancer. The aim of using this tool is to target the lymph nodes that are the most likely to be involved with metastatic cancer cells (sentinel lymph nodes) and thereby limit the extent of surgery needed and decrease surgical complications and long-term side effects associated with extensive lymph node removal. By examining a limited number of sentinel lymph nodes, a more detailed examination of the node can be done (ultrastaging). This allows for the detection of a small number of cancer cells (low-volume metastasis) that can be missed with standard techniques.

Impact of Obesity on Sentinel Lymph Node Mapping in Patients with Newly Diagnosed Uterine Cancer Undergoing Robotic Surgery

PURPOSE

The aim of this study was to determine the impact of obesity on the rate of successful sentinel lymph node (SLN) mapping in patients with uterine cancer undergoing robotic surgery, and compare SLN detection rates using indocyanine green (ICG) versus blue dye.

METHODS

We reviewed robotic cases undergoing SLN mapping with a cervical injection from January 2011 to December 2013 using either blue dye or ICG with near-infrared (NIR) fluorescence imaging. Data were stratified by body mass index (BMI) and the dye used. Appropriate statistical tests were applied.

RESULTS

Overall, 472 cases were identified. Bilateral mapping was successful in 352 cases (75 %), and unilateral mapping was successful in 73 cases (15 %). Bilateral mapping was achieved in 266 (85 %) of 312 ICG cases compared with 86 (54 %) of 160 blue-dye cases (p < 0.001). Cases with successful bilateral mapping had a median BMI of 29.8 kg/m(2) (range 16.3-65.3 kg/m(2)); cases with no mapping had a median BMI of 34.7 kg/m(2) (range 21.4-60.4 kg/m(2)) (p = 0.001). With increasing BMI, there was a significant decrease in successful bilateral mapping rates for both the ICG (p < 0.001) and blue-dye groups (p = 0.041); however, the use of ICG resulted in better bilateral (p = 0.002) and overall (p = 0.011) mapping rates compared with the use of blue dye in all BMI groups.

CONCLUSIONS

ICG results in a higher overall and bilateral SLN detection than blue dye in women with uterine cancer. Successful mapping decreases with increasing BMI irrespective of the dye used; however, it is significantly improved with the use of ICG and NIR fluorescence imaging compared with blue dye.

Laparoscopic sentinel lymph node mapping after cervical injection of indocyanine green for endometrial cancer - preliminary report

Introduction

Endometrial cancer (EC) has an increasing incidence worldwide, with lymph node metastases as the main prognostic factor. Systemic lymphadenectomy is connected with elevated morbidity. Sentinel lymph node (SLN) biopsy is intended to avoid extensive lymphadenectomy and provide significant oncologic information.

Aim

To evaluate the accuracy of laparoscopic SLN biopsy guided by indocyanine green (ICG) injection into the cervix in EC patients and to develop ideas to improve this method. The optimal time from dye injection to lymph node visualization was assessed.

Material and methods

This retrospective study was conducted between July 2014 and March 2015 in a group of 9 women with EC, at low and intermediate risk of recurrence, scheduled for total laparoscopic hysterectomy and pelvic lymphadenectomy. All patients underwent cervical ICG injection and SLN biopsy, followed by surgery. Pelvic lymph nodes were located using an ICG endoscopic camera.

Results

The following data were collected: There were 9 patients with endometrial cancer at low and intermediate risk of recurrence. Median patient age was 59 years, median body mass index (BMI) 28 kg/m², endometrioid adenocarcinoma in 9 cases, grading: G1 – 1 patient, G2 – 8 patients. No intraoperative or postoperative complications were noted. Median time from ICG injection and SLN detection during surgery was 25 min. There were no lymph nodes metastasis, all identified by the SLN protocol using ICG injection.

Conclusions

Sentinel lymph node mapping can play a significant role in lymph node assessment and staging in early-stage EC patients with low risk of recurrence according to the ESMO classification. The use of SLN mapping in EC is much needed and the therapeutic benefit is high.

Comparing indocyanine green, technetium, and blue dye for sentinel lymph node mapping in endometrial cancer

BACKGROUND AND AIMS

With the debate over extent of lymphadenectomy in endometrial cancer, sentinel lymph node (SLN) mapping may provide a focused approach to evaluate the most relevant lymph nodes (LN) while minimizing the complications. We evaluated SLN mapping using filtered technetium(99), indocyanine green (ICG), and blue dye.

METHODS

Prospective evaluation of 100 patients who underwent SLN mapping by using submucosal and deep stromal cervical injections of technetium(99), ICG, and blue dye as part of the staging for endometrial cancer.

RESULTS

286 SLNs were mapped (2.9 per patient) in 92% of patients. The bilateral detection rate was 76%. ICG had a significantly higher SLN detection rate than blue dye in both overall (87% vs 71%, respectively; p=0.005) and bilateral (65% vs 43%, respectively; p=0.002) detection, but similar SLN detection rates compared to technetium(99) in both overall (87% vs 88%, respectively; p=0.83) and bilateral (65% vs 71%, respectively; p=0.36) detection. In eight cases, the SLN was in the para-aortic area and in 14 cases in the pre-sacral, hypogastric vein, or parametrial area. In nine cases, the SLN was positive for metastasis, and in seven cases the SLN was the only positive node. One SLN was falsely negative. No complications or anaphylactic reactions occurred.

CONCLUSION

Intra-operative SLN mapping using cervical injection is feasible in patients with endometrial cancer and yields adequate detection rates. It allows mapping of SLNs in areas (pre-sacral, hypogastric vein, parametrial) not routinely sampled. Given the poorer performance of blue dye, surgeons may omit its use if a combination of ICG and technetium(99) is used.

Laparoscopic sentinel lymph node detection after hysteroscopic injection of technetium-99 in patients with endometrial cancer

BACKGROUND AND OBJECTIVES

Endometrial cancer (EC) has an increasing incidence worldwide. Despite the unequivocal prognostic importance of nodal status, systematic lymphadenectomy is associated to elevated morbidity. Sentinel lymph node (SLN) biopsy is designed to avoid extensive nodal dissection and provide crucial oncologic information. The goal of this prospective study was to determine the feasibility, safety, and accuracy of laparoscopic SLN biopsy in EC obtained through hysteroscopic injection of technetium-99 (Tc-99).

METHODS

From January 2008 to December 2012, a total of 42 women with EC were included in the study. We injected 20 mBq of Tc-99 hysteroscopically underneath the tumor minutes before definitive surgery. Thereafter, laparoscopic SLN identification /biopsy followed by pelvic and para-aortic lymphadenectomy, hysterectomy, and bilateral salpingo-oophorectomy were executed.

RESULTS

The total number of removed nodes was 970. The detection rate of the method was 73% (31/42). Among the 70 isolated SLNs, 35% (24) were exclusively identified in the para-aortic area. Fourteen patients (45%) had SLN only in the pelvic region, whereas 11 (35%) had SLN in both pelvic and para-aortic areas and 6 women (20%) had isolated para-aortic SNL. Nodal metastases were histologically confirmed in 9 patients (22%), and SLN was identified in 7 of 9 patients (78%). Although the obtained specificity was 100% and the negative predictive value was 89%, the sensitivity was only 58% (false-negative rate of 42%).

CONCLUSIONS

We could demonstrate that endoscopic SLN biopsy obtained through hysteroscopic injection of Tc-99 is a feasible and safe method. Despite the restricted number of included patients in this series, the obtained sensitivity and false-negative rates raise some questions about the real accuracy of the procedure in EC. Larger validation trials requiring quality pelvic and para-aortic lymphadenectomy are essential to correctly evaluate the method.

Relevance of sentinel lymph node procedure for patients with high-risk endometrial cancer

OBJECTIVE

While the accuracy of the Sentinel Lymph Node (SLN) procedure has been validated in patients with early-stage endometrial cancer (EC) at low and intermediate risk of recurrence, its relevance for high-risk EC remains unknown. The aim of this study was to evaluate the contribution of SLN biopsy in staging patients with presumed high-risk EC.

METHODS

This retrospective multicenter study, conducted from January 2001 to December 2012, included 180 patients with early-stage EC undergoing SLN biopsy. Detection rate and false negative rate were assessed according to risk groups of recurrence.

RESULTS

SLNs were detected in 159/180 patients (88%) and were bilateral in 63% of cases. Of the 180 patients, 41 (22%) had a positive lymph node. Ultrastaging detected metastases undiagnosed by conventional histology in 17/41 patients (41%). The false negative rate was 6% (9/159); 2.3% in the low/intermediate risk group and 20% in the high-risk group (p = 0.0008). Lymphovascular space invasion (LVSI) was present in 48 patients (27%). Preoperative findings classified 146 patients as ESMO low/intermediate risk (81%) and 34 as high risk (19%). Ten of the 34 patients (29%) in the presumed high-risk group were downstaged on final histology and 5/18 patients (28%) initially diagnosed with type 2 were finally classified as having type 1 EC. Classification was more likely discordant for patients with preoperative type 2 EC (p = 0.03) and in the initial high-risk group (p = 0.02).

CONCLUSIONS

SLN biopsy associated with LVSI status can select which high-risk patients with EC would benefit from comprehensive staging.

A comparison of colorimetric versus fluorometric sentinel lymph node mapping during robotic surgery for endometrial cancer

OBJECTIVE

The study objective was to compare the ability to detect sentinel lymph nodes (SLNs) in women with endometrial cancer (EC) or complex atypical hyperplasia (CAH) using fluorometric imaging with indocyanine green (ICG) versus colorimetric imaging with isosulfan blue (ISB).

METHODS

Women underwent SLN mapping, with either ISB or ICG, during robotic-assisted total laparoscopic hysterectomy (RA-TLH) from September 2012 to March 2014. SLNs were submitted for permanent pathologic analysis. Completion lymphadenectomy and ultrastaging were performed according to institutional protocols.

RESULTS

RA-TLH and SLN mapping was performed in 71 women; 64 had EC (64) and 7 had CAH. Age, body mass index (BMI), stage and tumor characteristics were similar in the ICG versus the ISB cohorts. Overall, SLNs were identified bilaterally (62.0%), unilaterally (21.1%), or neither (16.9%), and in 103 of 142 hemi-pelvises (72.5%). The mean number of SLNs retrieved per hemipelvis was 2.23(SD 1.7). SLNs were identified in the hypogastric (76.8%), external iliac (14.2%), common iliac (4.5%) and paraaortic (4.5%) regions. ICG mapped bilaterally in 78.9% of women compared with 42.4% of those injected with ISB (p=0.02). Five women (7%) had positive lymph nodes, all identified by the SLN protocol (false negative rate: 0%). On multivariate analysis, BMI was negatively correlated with bilateral mapping success (p=0.02). When stratified by dye type, the association with BMI was only significant for ISB (p=0.03).

CONCLUSIONS

Fluorescence imaging with ICG may be superior to colorimetric imaging with ISB in women undergoing SLN mapping for endometrial cancer. SLN mapping success is negatively associated with increasing patient BMI only when ISB is used.

Detection of sentinel lymph nodes in minimally invasive surgery using indocyanine green and near-infrared fluorescence imaging for uterine and cervical malignancies

OBJECTIVES

Our primary objective was to assess the detection rate of sentinel lymph nodes (SLNs) using indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging for uterine and cervical malignancies.

METHODS

NIR fluorescence imaging for the robotic platform was obtained at our institution in 12/2011. We identified all cases planned for SLN mapping using fluorescence imaging from 12/2011-4/2013. Intracervical ICG was the fluorophobe in all cases. Four cc (1.25mg/mL) of ICG was injected into the cervix alone divided into the 3- and 9-o'clock positions, with 1 cc deep into the stroma and 1 cc submucosally before initiating laparoscopic entry. Blue dye was concurrently injected in some cases.

RESULTS

Two hundred twenty-seven cases were performed. Median age was 60 years (range, 28-90 years). Median BMI was 30.2 kg/m(2) (range, 18-60 kg/m(2)). The median SLN count was 3 (range, 1-23). An SLN was identified in 216 cases (95%), with bilateral pelvic mapping in 179 (79%). An aortic SLN was identified in 21 (10%) of the 216 mapped cases. When ICG alone was used to map cases, 188/197 patients mapped, for a 95% detection rate compared to 93% (28/30) in cases in which both dyes were used (P=NS). Bilateral mapping was seen in 156/197 (79%) ICG-only cases and 23/30 (77%) ICG and blue dye cases (P=NS).

CONCLUSIONS

NIR fluorescence imaging with intracervical ICG injection using the robotic platform has a high bilateral SLN detection rate and appears favorable to using blue dye alone and/or other modalities. Combined use of ICG and blue dye appears unnecessary.

Histological features associated with occult lymph node metastasis in FIGO clinical stage I, grade I endometrioid carcinoma

AIMS

Lymph node involvement affects prognosis/treatment in endometrial carcinoma patients. We assessed various histological features associated with nodal metastasis in patients with grade I, stage I endometrial endometrioid carcinoma (EEC).

METHODS AND RESULTS

Eighteen stage I EECs with occult positive lymph nodes and 36 controls were assessed for depth of myoinvasion; microcystic, elongated and fragmented (MELF) pattern of myometrial invasion; lymphovascular invasion (LVI); and epithelial metaplasia. Nodal metastases were subclassified as isolated tumour cells (ITCs; ≤0.2 mm), micrometastasis (>0.2 mm and <2 mm), or macrometastasis (≥2 mm). Node-positive cases had significantly higher rates of LVI (P < 0.001) and MELF invasion (P = 0.003) on univariate analysis. Only LVI was associated significantly with nodal metastasis on multivariate analysis (P = 0.002). Tumours with MELF invasion demonstrated reduced E-cadherin expression. Macrometastases were identified in seven cases (39%) with or without micrometastasis/ITCs. Eight (44%) contained only ITCs. Eleven (61%) had histiocyte-like nodal metastases. Biopsy material from four of six (67%) and five of 17 (29%) cases with and without nodal metastasis showed detached eosinophilic tumour cell buds. Of the former, three were associated with histiocyte-like nodal metastases - a feature absent in biopsies without tumour budding.

CONCLUSIONS

Lymph nodes from grade I EEC exhibiting cellular budding or LVI should be examined for occult metastases, especially in the form of histiocyte-like cells.

Is sentinel lymph node dissection an appropriate standard of care for low-stage endometrial cancers? A review of the literature

BACKGROUND/AIMS

To review the literature and compare detection rates, false negative (FN) rates, and negative predictive values (NPVs) of sentinel lymph node (SLN) biopsy in endometrial cancer to those in breast and vulvar cancer. Secondary objectives were to evaluate techniques of SLN biopsy in endometrial cancer.

METHODS

The PubMed database was searched for applicable scientific articles. Detection rates, FN rates, and NPVs were calculated for all studies. Studies were stratified by techniques and compared.

RESULTS

Nineteen articles met criteria for this review. The overall detection rates ranged from 62 to 100%, the FN rate ranged from 0 to 50%, and the NPVs ranged from 95 to 100%. There is no technique that is definitively superior to any other with regard to surgical modality, injectant used, injection site, or pathologic techniques.

CONCLUSIONS

Studies on SLN biopsy in endometrial cancer have a large range of detection rates and FN rates, and larger studies including more patients with metastatic disease are needed for comparison with breast and vulvar cancers. While no techniques are definitively superior to others, minimally invasive surgery, cervical injection, and pathologic analysis utilizing HE staining, immunohistochemistry, and ultrastaging may be clinically advantageous.

Study of the sentinel node in endometrial cancer at early stages: preliminary results

AIM

To investigate the applicability of the sentinel lymph node biopsy technique in early stages of endometrial cancer.

MATERIAL AND METHODS

A prospective study that included consecutive patients with a histological diagnosis of clinical state I endometrial carcinoma was performed. Two doses of 2 mCi (74 MBq) of (99m)Tc-albumin nanocolloid were injected in the uterine cervix, and planar and SPECT-CT images were obtained at one hour, and at 24 hours if no migration of the tracer was observed. Methylene blue dye was also injected into the cervix immediately prior to the surgery. A gamma probe was used during the surgical procedure for sentinel lymph node identification. In all cases, a hysterectomy, double adnexectomy and pelvic lymphadenectomy were performed, carrying out a histological analysis (hematoxylin-eosin) of the sentinel lymph nodes and the lymphadenectomy specimen.

RESULTS

We included 19 patients, with a final diagnoses of endometrioid carcinoma (18 cases) and endometrial stromal sarcoma (1 case). At least one sentinel lymph node was identified in 17 of them (89.5% detection rate). Twenty-nine sentinel lymph nodes were identified during surgery, all of them negative for neoplastic infiltration. No metastatic invasion was found in the pelvic lymphadenectomy specimens as well.

CONCLUSIONS

The sentinel lymph node biopsy technique seems to be a reliable tool in nodal staging of endometrial cancer at early stages, with an acceptable detection rate and high histological correlation. The low prevalence of lymphatic spread in this group of patients and the encouraging results obtained could make the sentinel lymph node an alternative to routine complete lymphadenectomy.

Added value of intraoperative real-time imaging in searches for difficult-to-locate sentinel nodes

Localization of sentinel lymph nodes can be challenging if they are in difficult anatomic locations or near high radiotracer activity. The purpose of this study was to assess the value of intraoperative real-time imaging using a portable gamma-camera in conjunction with a conventional gamma-counting probe when it is difficult to localize the sentinel node.

METHODS

After (99m)Tc-nanocolloid injection, patients with various malignancies underwent presurgical lymphoscintigraphy followed by surgery (usually the next day). We evaluated 20 patients who required sentinel lymph node biopsy and in whom the location or other characteristics of the sentinel node would make intraoperative retrieval difficult. During surgery, the sentinel node was localized using a portable gamma-camera together with a hand-held gamma-probe. A (153)Gd pointer or (125)I seed was used to better depict the sentinel node location in real time.

RESULTS

Using only a conventional hand-held gamma-probe, surgeons were able to definitively localize the sentinel node in 15 of 20 patients. Intraoperatively, the portable gamma-camera showed uptake by the definite sentinel node in 19 of 20 patients and helped to precisely localize the node with the hand-held gamma-probe in 4 patients. In 1 of these patients, the sentinel node was metastatic.

CONCLUSION

The combination of a standard hand-held gamma-probe and real-time imaging provided by a portable gamma-camera offers a high intraoperative detection rate in patients with difficult sentinel node localization as assessed by presurgical lymphoscintigraphy.

The laparoscopic-assisted vaginal approach to early endometrial cancer

INTRODUCTION

For the surgical treatment of endometrial cancer laparotomy still is regarded as the gold standard. Over the past decade, the laparoscopic approach has gained equivalence in FIGO stage I carcinomas.

RESULTS

Laparoscopic-assisted vaginal hysterectomy and bilateral salpingooophorectomy plus pelvic/paraaortic lymphadenectomy have shown short-term advantages such as reduced blood loss and shorter hospitalization without reducing oncological safety or outcome. This has already been confirmed by numerous smaller studies and recent randomized controlled trials with sufficient numbers of patients are being published.

CONCLUSION

Further acceptance of the technique is necessary to enable every gynecological oncologist to individualize treatment by offering minimal access options.

The role of sentinel node biopsy in gynecological cancer: a review

PURPOSE OF REVIEW

In early-stage vulvar, cervical and endometrial cancer, lymph node status is the most important prognostic factor. Surgical treatment is aimed at removing the primary tumor and adequately staging the regional lymph nodes. As morbidity of regional lymphadenectomy is high, sentinel node biopsy is a technique with potential for adequate staging with less treatment-related morbidity. This manuscript reviews its current role in vulvar, cervical and endometrial cancer.

RECENT FINDINGS

In early-stage vulvar cancer, level 3 evidence indicates that it appears to be safe to omit inguinofemoral lymphadenectomy in case of a negative sentinel node. However, false-negative results with fatal consequences do occur and are often attributable to procedural failures. For early-stage cervical cancer, level 3 evidence points to an acceptable false-negative rate of a negative sentinel node; clinical utility and safety remain to be established. The optimal technique of the sentinel node biopsy in endometrial cancer is currently unclear.

SUMMARY

In early-stage vulvar cancer, data suggest that sentinel node biopsy could be offered as a treatment option instead of routine inguinofemoral lymphadenectomy. However, more (long-term follow-up) data are needed to further appreciate real clinical benefits. It is emphasized that the procedure should be performed by a skilled multidisciplinary team, centralized in oncology centers and preferably within the protection of clinical trials. For cervical cancer, data are promising, but routine application cannot be recommended due to lack of data on clinical utility and safety. For endometrial cancer, studies on the sentinel node biopsy are still in feasibility stage.

Sentinel lymph node mapping for grade 1 endometrial cancer: is it the answer to the surgical staging dilemma?

OBJECTIVE

To describe the accuracy of SLN mapping in patients with a preoperative diagnosis of grade 1 endometrial cancer.

METHODS

A prospective, non-randomized study of women with a preoperative diagnosis of endometrial cancer and clinical stage I disease was conducted. A subset analysis of patients with a preoperative diagnosis of grade 1 endometrial endometrioid cancer was performed. All patients had preoperative lymphoscintigraphy with Tc99m on the day of or day before surgery followed by an intraoperative injection of 2 cm(3) of isosulfan or methylene blue dye deep into the cervix or both cervix and fundus. All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and regional nodal dissection. Hot and/or blue nodes were labeled as SLNs and sent for histopathological analysis.

RESULTS

Forty-two patients with a preoperative diagnosis of grade 1 endometrial carcinoma treated from 3/06 to 8/08 were identified. Twenty-five (60%) had laparoscopic surgery; 17 (40%) were treated by laparotomy. Preoperative lymphoscintigraphy visualized SLNs in 30 patients (71%); intraoperative localization of the SLN was possible in 36 patients (86%). A median of 3 SLNs (range, 1-14) and 14.5 non-SLNs (range, 4-55) were examined. In all, 4/36 (11%) had positive SLNs-3 seen on H&E and 1 as cytokeratin-positive cells on IHC. All node-positive cases were picked up by the SLN; there were no false-negative cases. The sensitivity of the SLN procedure in the 36 patients who had an SLN identified was 100%.

CONCLUSION

Sentinel lymph node mapping using a cervical injection with combined Tc and blue dye is feasible and accurate in patients with grade 1 endometrial cancer and may be a reasonable option for this select group of patients. Regional lymphadenectomy remains the gold standard in many practices, particularly for the approximately 15% of cases with failed SLN mapping.

Update on sentinel lymph node biopsy in gynecologic cancers

The sentinel lymph node biopsy (SLNB) holds the promise of more accurate staging of the primary tumor and fewer wound complications and lymphedema than associated with lymphadenectomy. Regional lymphadenectomy may no longer be a requirement in SLNB-negative patients if the SLN procedure is adequately validated in prospective clinical trials for gynecologic malignancies.