Utilization and Outcomes of Sentinel Lymph Node Biopsy for Early Endometrial Cancer

Geographic and racial disparities in the quality of surgical care among patients with nonmetastatic uterine cancer

BACKGROUND

Although the rates of minimally invasive surgery and sentinel lymph node biopsy have increased considerably over time in the surgical management of early-stage uterine cancer, practice varies significantly in the United States, and there are disparities among low-volume centers and patients of Black race. A significant number of counties in the United States are without a gynecologic oncologist, and almost half of the counties with the highest gynecologic cancer rates lack a local gynecologic oncologist.

OBJECTIVE

This study aimed to evaluate the relationships of distance traveled and proximity to gynecologic oncologists with the receipt of and racial disparities in the quality of surgical care among patients who underwent a hysterectomy for nonmetastatic uterine cancer.

STUDY DESIGN

Patients who underwent a hysterectomy for nonmetastatic uterine cancer in Kentucky, Maryland, Florida, and North Carolina were identified in the 2012 to 2018 State Inpatient Database and the State Ambulatory Surgery Services Database files. County-to-county distances were used as the distances traveled to the nearest gynecologic oncologist. Factors associated with the receipt of minimally invasive surgery and lymph node dissection were analyzed using multivariable logistic regression models, as was the assessment of the interaction between travel for surgery and patient race.

RESULTS

Among 21,837 cases, 45.5% lived in a county without a gynecologic oncologist; overall, 55.5% traveled to another county for surgery, including 88% of those who lacked a local gynecologic oncologist. Patients who lacked access to a local gynecologic oncologist in their county who did not travel for surgery were more likely to receive open surgery and no lymph node dissection, and those in counties without access in any surrounding county were affected even more. Among patients in counties without a gynecologic oncologist, those who traveled for surgery had a similar likelihood of undergoing minimally invasive surgery (71%) but had a greater likelihood of undergoing lymph node dissection (64.7% vs 57.2%) than nontravelers. Among those in counties without a gynecologic oncologist, a longer distance traveled was associated with receipt of a lymph node assessment. When compared with non-Black patients, Black patients were less likely to undergo minimally invasive surgery (57.0% vs 74.1%). In adjusted regression models that controlled for a diagnosis of fibroids, Black race was an independent risk factor for the receipt of open surgery. There was a significant interaction between Black race and travel for surgery, and Black patients who lived in counties without a gynecologic oncologist who did not travel faced an incrementally lower likelihood of receiving minimally invasive surgery (odds ratio, 0.57 when compared with non-Black patients who traveled for surgery; odds ratio, 0.60 as interaction term; P<.001 for both). Similar disparities in surgical quality by race were noted for Black patients who lived in counties with a gynecologic oncologist who traveled out of county for surgery.

CONCLUSION

Patients, particularly those of Black race, who lacked local access to gynecologic oncologist specialty care benefitted from traveling to specialty centers to ensure access to high-quality surgery for nonmetastatic uterine cancer. Further work is needed to ensure equitable and universal access to high-quality care through patient travel or specialist outreach.

Risks and benefits of sentinel lymph node evaluation in the management of endometrial intraepithelial neoplasia

INTRODUCTION

Endometroid intraepithelial neoplasia (EIN) is a premalignant lesion to endometrial cancer. Increasing number of gynecologic oncologists are performing sentinel lymph node (SLN) evaluation during hysterectomy for EIN to ensure complete staging if there is cancer on the final specimen. However, there are no clear guidelines and the benefits and risks to performing SLN evaluation for EIN patients are unclear.

AREAS COVERED

This narrative review examines the advantages and disadvantages of SLN evaluation for EIN patients and provides an algorithm to assist clinicians in selectively applying the procedure for maximal patient benefit. Relevant articles up to March 2024 were obtained from a PubMed search on SLN use with endometrial pathology.

EXPERT OPINION

Sentinel lymph node evaluation for patients with EIN is safe, feasible, and particularly important for the approximately 10% of patients with high-risk endometrial carcinoma on final pathology. However, as most diagnosed carcinomas are low-risk, SLN evaluation would have limited oncologic benefit. While SLN assessment may overtreat most patients with EIN, a significant minority of patients will be improperly staged. We propose an algorithm highlighting the importance of maximal preoperative endometrial sampling and stratifying patients via risk factors to selectively identify those who would benefit most from SLN evaluation.

Prognostic performance of the 2023 FIGO staging schema for endometrial cancer

OBJECTIVE

To assess the prognostic performance of the 2023 International Federation of Gynecology and Obstetrics (FIGO) endometrial cancer staging schema.

METHODS

This retrospective cohort study queried the Commission-on-Cancer's National Cancer Database. Study population was 129,146 patients with stage I-IV endometrial cancer per the 2009 FIGO staging schema. Stage-shifting and overall survival (OS) were assessed according to the 2023 FIGO staging schema.

RESULTS

Upstage (IA → II, 21.4 %; IB → II, 53.0 %) and downstage (IIIA→IA3, 22.2 %) occurred in both early and advanced diseases. Inter-stage prognostic performance improved in the 2023 schema with widened 5-year OS rate difference between the earliest and highest stages (68.2 % to 76.9 %). Stage IA1-IIB and IIC had distinct 5-year OS rate differences (85.8-96.1 % vs 75.4 %). The 5-year OS rate of the 2009 stage IIIA disease was 63.9 %; this was greater segregated in the 2023 schema: 88.0 %, 62.4 %, and 55.7 % for IIIA→IA3, IIIA1, and IIIA2, respectively (inter-substage rate-difference, 32.3 %). This 5-year OS rate of stage IA3 disease was comparable to the 2023 stage IB-IIB diseases (88.0 % vs 85.8-89.5 %). In the 2023 stage IIIC schema (micrometastasis rates: 29.6 % in IIIC1 and 15.6 % in IIIC2), micrometastasis and macrometastasis had the distinct 3-year OS rates in both pelvic (IIIC1-i vs IIIC1-ii, 84.9 % vs 71.1 %; rate-difference 13.8 %) and para-aortic (IIIC2-i vs IIIC2-ii, 82.9 % vs 65.2 %; rate-difference 17.7 %) nodal metastasis cases. The 5-year OS rate of the 2009 stage IVB disease was 23.4 %; this was segregated to 25.4 % for stage IVB and 19.2 % for stage IVC in the 2023 staging schema (rate-difference, 6.2 %).

CONCLUSION

The 2023 FIGO endometrial cancer staging schema is a major revision from the 2009 FIGO schema. Almost doubled enriched sub-stages based on detailed anatomical metastatic site and incorporation of histological information enable more robust prognostication.

Utilization and Surgical Outcomes of Sentinel Lymph Node Biopsy for Endometrial Intraepithelial Neoplasia

OBJECTIVE

To describe the rate and surgical outcomes of sentinel lymph node (SLN) biopsy in patients with endometrial intraepithelial neoplasia (EIN).

METHODS

We conducted a cohort study that used the prospective American College of Surgeons National Surgical Quality Improvement Program database. Women with EIN on postoperative pathology who underwent minimally invasive hysterectomy from 2012 to 2020 were included. The cohort was dichotomized based on the performance of SLN biopsy. Patients' characteristics, perioperative morbidity, and mortality were compared between patients who underwent SLN biopsy and those who did not. Postoperative complications were defined using the Clavien-Dindo classification system.

RESULTS

Overall, 4,447 patients were included; of those, 586 (13.2%) underwent SLN biopsy. The proportion of SLN biopsy has increased steadily from 0.6% in 2012 to 26.1% in 2020 ( P <.001), with a rate of 16% increase per year. In a multivariable regression that included age, body mass index (BMI), and year of surgery, a more recent year of surgery was independently associated with an increased adjusted odds ratio of undergoing SLN biopsy (1.51, 95% CI, 1.43-1.59). The mean total operative time was longer in the SLN biopsy group (139.50±50.34 minutes vs 131.64±55.95 minutes, P =.001). The rate of any complication was 5.9% compared with 6.7%, the rate of major complications was 2.3% compared with 2.4%, and the rate of minor complications was 4.1% compared with 4.9% for no SLN biopsy and SLN biopsy, respectively. In a single complications analysis, the rate of venous thromboembolism was higher in the SLN biopsy group (four [0.7%] vs four [0.1%], P =.013). In a multivariable regression analysis adjusted for age, BMI, American Society of Anesthesiologists classification, uterus weight, and preoperative hematocrit, the performance of SLN biopsy was not associated with any complications, major complications, or minor complications.

CONCLUSION

The performance of SLN biopsy in EIN is increasing. Sentinel lymph node biopsy for EIN is associated with an increased risk of venous thromboembolism and a negligible increased surgical time.

Is it safe to operate selected low-risk endometrial cancer patients in secondary hospitals?

INTRODUCTION

The aim of this study was to assess the accuracy of a preoperative screening algorithm in identifying low-risk endometrial cancer (EC) patients to ensure optimal care.

METHODS

A total of 277 patients with primary EC confirmed through biopsy underwent magnetic resonance imaging (MRI). Patients with risk factors for advanced high-risk EC, such as non-endometrioid histology, high-grade differentiation status, deep myometrial invasion, or spread beyond the uterine corpus, were systematically excluded. The remaining preoperatively screened patients with stage IA low-grade endometrioid EC (EEC) (n = 93) underwent surgery in a tertiary hospital. The accuracy of the preoperative diagnosis was evaluated by comparing the findings with the postoperative histopathological results. Disease-free survival (DFS) and overall survival (OS) were analyzed using 8-year follow-up data.

RESULTS

Postoperative histopathological analysis revealed that all patients had grade 1-2 EEC localized to the corpus uteri. Only three patients had deep myometrial invasion (stage IB), but they remained disease-free after 6-9 years of follow-up. The median follow-up time for all patients was 8.7 years. The DFS was 7.6 years, and the OS was 8.6 years. Two patients with stage IA grade 1 EEC experienced relapse and, despite treatment, died of EC. No other EC-related deaths occurred.

CONCLUSIONS

The screening algorithm accurately identified low-risk EC patients without compromising survival. Therefore, the algorithm appears to be feasible for selecting patients for surgery in secondary hospitals.

Increasing utilization of intrauterine device insertion at hysteroscopic endometrial evaluation for patients with endometrial hyperplasia

PURPOSE

To examine the utilization and characteristics related to the use of hysteroscopy at the time of endometrial evaluation for endometrial hyperplasia in the outpatient surgery setting.

METHODS

This cross-sectional study queried the Healthcare Cost and Utilization Project's Nationwide Ambulatory Surgery Sample. The study population was 3218 patients with endometrial hyperplasia who underwent endometrial evaluation from January 2016 to December 2019. Performance and clinical characteristics of hysteroscopic endometrial evaluation were assessed with multivariable binary logistic regression models.

RESULTS

A total of 2654 (82.5%) patients had hysteroscopic endometrial tissue evaluation. Patients with postmenopausal bleeding, heavy menstrual bleeding, and polycystic ovary syndrome were more likely to undergo hysteroscopic endometrial evaluation in multivariable analysis (all, adjusted-P < 0.001). Uterine injury occurred in 4.9 per 1000 hysteroscopic endometrial evaluations; none had uterine injury in the non-hysteroscopy cohort. Among the 2654 patients who had hysteroscopic endometrial evaluation, 106 (4.0%) patients had intrauterine device insertion at surgery, and the utilization increased from 2.9 to 5.8% during the study period (P-trend < 0.001). Younger age, more recent year surgery, and obesity were independently associated with increased utilization of intrauterine device insertion at hysteroscopic endometrial evaluation (all, adjusted-P < 0.05). Among 2023 reproductive-age patients with endometrial hyperplasia, 1666 (82.4%) patients underwent hysteroscopic endometrial evaluation. On multivariable analysis, patients with heavy menstrual bleeding were more likely to have hysteroscopic endometrial evaluation (adjusted-P < 0.05). Intrauterine device insertion increased from 3.7% in 2016 to 8.0% in 2019 (P-trend = 0.007).

CONCLUSION

This nationwide analysis suggests that the insertion of intrauterine devices at the time of hysteroscopic endometrial tissue evaluation for endometrial hyperplasia is increasing among reproductive-age population.

Lymph Node Isolated Tumor Cells in Patients With Endometrial Cancer

Importance

Isolated tumor cells (ITCs) are the histopathological finding of small clusters of cancer cells no greater than 0.2 mm in diameter in the regional lymph nodes. For endometrial cancer, the prognostic significance of ITCs is uncertain.

Objective

To assess clinico-pathological characteristics and oncologic outcomes associated with ITCs in endometrial cancer.

Design, Setting, and Participants

This retrospective cohort study using the National Cancer Database included patients with endometrial cancer who had primary hysterectomy and nodal evaluation from 2018 to 2020. Patients with microscopic and macroscopic nodal metastases and distant metastases were excluded. Data were analyzed from June to September 2023.

Exposure

Regional nodal status with ITCs (N0[i+] classification) or no nodal metastasis (N0 classification).

Main Outcomes and Measures

(1) Clinical and tumor characteristics associated with ITCs, assessed with multivariable binary logistic regression model, and (2) overall survival (OS) associated with ITCs, evaluated by nonproportional hazard analysis with restricted mean survival time at 36 months.

Results

A total of 56 527 patients were included, with a median (IQR) age of 64 (57-70) years. The majority had T1a lesion (37 836 [66.9%]) and grade 1 or 2 endometrioid tumors (40 589 [71.8%]). ITCs were seen in 1462 cases (2.6%). In a multivariable analysis, ITCs were associated with higher T classification, larger tumor size, lymphovascular space invasion (LVSI), and malignant peritoneal cytology. Of those tumor factors, LVSI had the largest association with ITCs (7.9% vs 1.4%; adjusted odds ratio [aOR], 4.37; 95% CI, 3.87-4.93), followed by T1b classification (5.3% vs 1.3%; aOR, 2.62; 95% CI, 2.30-2.99). At the cohort level, 24-month OS rates were 94.3% (95% CI, 92.4%-95.7%) for the ITC group and 96.1% (95% CI, 95.9%-96.3%) for the node-negative group, and the between-group difference in expected mean OS time at 36 months was 0.35 (SE, 0.19) months, but it was not statistically significant (P = .06). There was a statistically significant difference in OS when the low-risk group (stage IA, grade 1-2 endometrioid tumors with no LVSI) was assessed per nodal status and adjuvant therapy use (P < .001): (1) among the cases treated with surgical therapy alone, 24-month OS rates were 95.9% (95% CI, 89.5%-98.5%) for the ITC group and 98.8% (95% CI, 98.6%-99.0%) for the node-negative group, and the between-group mean OS time difference at 36 months was 0.61 (SE, 0.43) months (P = .16); and (2) among the cases with ITCs, adjuvant therapy (radiotherapy alone, systemic chemotherapy alone, or both) was associated with improved survival compared with no adjuvant therapy (24-month OS rates, 100% vs 95.9%; between-group mean OS time difference at 36 months, 0.95 [SE, 0.43] months; P = .03).

Conclusions and Relevance

In this cohort study of patients with surgically staged endometrial cancer, the results of exploratory analysis suggested that presence of ITCs in the regional lymph node may be associated with OS in the low-risk group. While adjuvant therapy was associated with improved OS in the low-risk group with ITCs, careful interpretation is necessary given the favorable outcomes regardless of adjuvant therapy use. This hypothesis-generating observation in patients with low-risk endometrial cancer warrants further investigation, especially with prospective setting.

In the patient's shoes: The impact of hospital proximity and volume on stage I endometrial cancer care patterns and outcomes

OBJECTIVE

To compare the impact of travel burden and hospital volume on care patterns and outcomes in stage I endometrial cancer.

METHODS

This retrospective cohort study identified patients from the National Cancer Database with stage I epithelial endometrial carcinoma who underwent hysterectomy between 2012 and 2020. Patients were categorized into: lowest quartiles of travel distance and hospital surgical volume for endometrial cancer (Local) and highest quartiles of distance and volume (Travel). Primary outcome was overall survival. Secondary outcomes were surgery route, lymph node (LN) assessment method, length of stay (LOS), 30-day readmission, and 30- and 90-day mortality. Results were stratified by tumor recurrence risk. Outcomes were compared using propensity-score matching. Propensity-adjusted survival was evaluated using Kaplan-Meier curves and compared using log-rank tests. Cox models estimated hazard ratios for death. Sensitivity analysis using modified Poisson regressions was performed.

RESULTS

Among 36,514 patients, 51.4% were Local and 48.6% Travel. The two cohorts differed significantly in demographics and clinicopathologic characteristics. Upon propensity-score matching (p < 0.05 for all), more Travel patients underwent minimally invasive surgery (88.1%vs79.1%) with fewer conversions to laparotomy (2.0%vs2.6%), more sentinel (20.5%vs11.3%) and fewer traditional LN assessments (58.1vs61.7%) versus Local. Travel patients had longer intervals to surgery (≥30 days:56.7%vs50.1%) but shorter LOS (<2 days:76.9%vs59.8%), fewer readmissions (1.9%vs2.7%%), and comparable 30- and 90-day mortality. OS and HR for death remained comparable between the matched groups.

CONCLUSIONS

Compared to surgery in nearby low-volume hospitals, patients with stage I epithelial endometrial cancer who travelled longer distances to high-volume centers experienced more favorable short-term outcomes and care patterns with comparable long-term survival.

Does sentinel node mapping impact morbidity and quality of life in endometrial cancer?

OBJECTIVES

To evaluate the prevalence of post-operative complications and quality of life (QoL) related to sentinel lymph node (SLN) biopsy vs systematic lymphadenectomy in endometrial cancer.

METHODS

A prospective cohort included women with early-stage endometrial carcinoma who underwent lymph node staging, grouped as follows: SLN group (sentinel lymph node only) and SLN+LND group (sentinel lymph node biopsy with addition of systematic lymphadenectomy). The patients had at least 12 months of follow-up, and QoL was assessed by European Organization for Research and Treatment of Cervical Cancer Quality of Life Questionnaire 30 (EORTC-QLQ-C30) and EORTC-QLQ-Cx24. Lymphedema was also assessed by clinical evaluation and perimetry.

RESULTS

152 patients were included: 113 (74.3%) in the SLN group and 39 (25.7%) in the SLN+LND group. Intra-operative surgical complications occurred in 2 (1.3%) cases, and all belonged to SLN+LND group. Patients undergoing SLN+LND had higher overall complication rates than those undergoing SLN alone (33.3% vs 14.2%; p=0.011), even after adjusting for confound factors (OR=3.45, 95% CI 1.40 to 8.47; p=0.007). The SLN+LND group had longer surgical time (p=0.001) and need for admission to the intensive care unit (p=0.001). Moreover, the incidence of lymphocele was found in eight cases in the SLN+LND group (0 vs 20.5%; p<0.001). There were no differences in lymphedema rate after clinical evaluation and perimetry. However, the lymphedema score was highest when lymphedema was reported by clinical examination at 6 months (30.1 vs 7.8; p<0.001) and at 12 months (36.3 vs 6.0; p<0.001). Regarding the overall assessment of QoL, there was no difference between groups at 12 months of follow-up.

CONCLUSIONS

There was a higher overall rate of complications for the group undergoing systematic lymphadenectomy, as well as higher rates of lymphocele and lymphedema according to the symptom score. No difference was found in overall QoL between SLN and SLN+LND groups.

Influence of lymphadenectomy on survival and recurrence in patients with early-stage epithelial ovarian cancer: a meta-analysis

BACKGROUND

This meta-analysis aimed to evaluate the effectiveness of lymphadenectomy on survival and recurrence in patients with early-stage epithelial ovarian cancer (eEOC).

METHODS

Relevant studies were searched from four online databases. Hazard ratios (HRs) with 95% confidence intervals (CIs) or risk ratios (RRs) with 95% CIs were used to evaluate the effects of lymphadenectomy on overall survival (OS), progression-free survival (PFS), and recurrence rates. A subgroup analysis was performed to explore the sources of heterogeneity, followed by sensitivity and publication bias assessments.

RESULTS

Fourteen articles involving 22,178 subjects were included. Meta-analysis revealed that lymphadenectomy was significantly associated with improved OS (HR = 0.72; 95% CI:0.61, 0.84; P < 0.001), improved PFS (HR = 0.74; 95% CI: 0.67, 0.80; P < 0.001), and reduced recurrence rates (RR = 0.72; 95% CI: 0.60, 0.85; P < 0.001). Subgroup analysis showed that factors including area, histology, and source of the control group were significantly related to improved OS and PFS in patients with eEOC. Sensitivity analysis showed that the combined results were stable and reliable, and no significant publication bias was observed.

CONCLUSIONS

Patients with eEOC can benefit from lymphadenectomy, with improved survival outcomes (OS and PFS) and a lower recurrence rate.

Increasing trends of cervical conization with lymph node evaluation for fertility-sparing surgery in early cervical cancer

OBJECTIVE

To examine uptake, characteristics, and survival outcome of less-radical fertility-sparing surgery with cervical conization and lymph node evaluation (Cone-LN) in reproductive age patients with early cervical cancer.

METHODS

This retrospective cohort study examined the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. The study population included 407 patients aged <50 years with stage IA-IB2 (≤4 cm) cervical cancer who received fertility-sparing surgery from 2004 to 2019. The exposure was fertility-sparing surgery type: Cone-LN (n = 196) or trachelectomy with lymph node evaluation (Trach-LN, n = 211). The main co-outcomes were (i) temporal trends of surgery type, assessed with Cochran-Armitage test, and (ii) clinical and tumor characteristics, assessed with multivariable binary logistic regression model. The secondary outcome was overall survival, assessed with inverse probability of treatment weighting propensity score.

RESULTS

The number of patients receiving Cone-LN increased from 43.5% in 2004-2007 to 58.4% in 2016-2019 (P-trend = 0.005). Patients receiving conization and sentinel lymph node (SLN) biopsy alone increased from 0% to 14.4% (P-trend < 0.001). In a multivariable analysis, patients in the Cone-LN group were more likely to undergo SLN biopsy (aOR 6.04) compared to those in the Trach-LN group whereas those with adenocarcinoma (aOR 0.49) and T1b tumors (aOR for ≤2 cm 0.21, and aOR for 2.1-4.0 cm 0.10) were less likely to receive Cone-LN. In a propensity score-weighted model, the Cone-LN and Trach-LN groups had comparable overall survival (7-year rates, 98.9% vs 97.8%). Similar associations were observed for patients with squamous, adenocarcinoma / adenosquamous, T1a classification, and T1b(≤2 cm) classification.

CONCLUSION

The current population-based analysis suggests that the performance of cervical conization with lymph node evaluation, particularly with SLN biopsy, is gradually increasing for early cervical cancer patients desiring future fertility.

Utilization of sentinel lymph node biopsy in the early ovarian cancer surgery

OBJECTIVE

Sentinel lymph node (SLN) biopsy has been incorporated into surgical care for many malignancies; however, the utility has not been examined in ovarian cancer. This study examined population-level trends, characteristics, and outcomes related to SLN biopsy in early stage ovarian cancer.

METHODS

This is a retrospective cohort study querying the National Cancer Institute's Surveillance, Epidemiology, and End Result Program from 2003-2018. The study population consisted of 11,512 women with stage I ovarian cancer who had adnexectomy-based surgical staging including lymph node evaluation. Exposure allocation was based on SLN biopsy use. Main outcomes measured were (i) trends and characteristics associated with SLN biopsy use, assessed by multivariable logistic regression model, and (ii) overall survival assessed with inverse provability of treatment weighting propensity score.

RESULTS

SLN biopsy was performed in less than 1% of study population. In a multivariable analysis, recent surgery (2011-2018 versus 2003-2010, odds ratio [OR] 1.64, 95% confidence interval [CI] 1.03-2.59), smaller tumor size (< 10 versus ≥ 10 cm, OR 3.07, 95% CI 1.20-7.84), and East registry area (OR 2.74, 95% CI 1.73-4.36) remained independent characteristics for SLN biopsy use. In a propensity score weighted model, 5-year overall survival rate was 90.5% for the SLN biopsy-incorporated group and 88.6% for the lymphadenectomy group (hazard ratio 0.96, 95% CI 0.53-1.73).

CONCLUSION

SLN biopsy was rarely performed for early ovarian cancer surgery during the study period with insufficient evidence to interpret the survival effect. SLN biopsy in early ovarian cancer appears to be in early development phase, warranting further study and careful evaluation to assess feasibility and oncologic outcome.

The Role of Sentinel Lymph Node Mapping in High-grade Endometrial Cancer

OPINION STATEMENT

Total hysterectomy with lymph node assessment is the current standard-of-care for surgical staging in apparent early-stage endometrial cancer. Compared to the traditional complete pelvic lymphadenectomy with or without para-aortic lymphadenectomy, sentinel lymph node (SLN) mapping results in fewer surgical complications, decreased operative time, and lower rates of chronic lymphedema. The technique is endorsed by the National Comprehensive Cancer Network and the Society of Gynecologic Oncology guidelines, and over the past two decades the majority of gynecologic oncologists worldwide have adopted SLN mapping into their practice. However, as the results of the initial SLN studies were mostly based on low-grade tumors, adoption of the technique in high-grade tumors has been slower and more controversial. In this review, we discuss the most recent studies evaluating the SLN mapping in high-grade endometrial cancers. The results of these studies suggest that the SLN detection rate is acceptably high and the negative predictive value is sufficiently low to support the use of SLN mapping in high-grade endometrial tumors to replace complete lymphadenectomy. Validity of SLN mapping techniques does, however, require following a standard algorithm, and success depends also on surgeon expertise. Moreover, the impact of SLN mapping on overall survival in high-grade tumors requires future prospective randomized studies. Finally, a transition toward near-universal SLN mapping techniques for endometrial cancers could significantly impact on the adequacy of gynecologic oncology fellows' surgical training and competency in lymphadenectomy.

Association between sentinel lymph node biopsy and micrometastasis in endometrial cancer

OBJECTIVE

Sentinel lymph node (SLN) biopsy is increasingly utilized at surgical staging for early endometrial cancer. This study examined the association between SLN biopsy and micrometastasis in endometrial cancer.

METHODS

This is a retrospective cohort study examining the National Cancer Institute's Surveillance, Epidemiology, and End Result Program. The study population was 6,414 women with T1-2 endometrial cancer who underwent primary hysterectomy and surgical nodal evaluation. Exclusion criteria included cases with isolated tumor cells. Exposure assignment was surgical nodal evaluation (SLN biopsy or lymphadenectomy). Main outcome measure was micrometastasis, assessed by inverse probability of treatment weighting propensity score in a stage-specific fashion.

RESULTS

In T1a disease (n = 4,608), SLN biopsy was performed in 1,164 (25.3%) cases. SLN biopsy was associated with a 90% increased likeliness of identifying micrometastasis compared to lymphadenectomy (1.3% versus 0.7%, odds ratio 1.90, 95% confidence interval 1.02-3.55, P = 0.040). In T1b disease (n = 1,369), 270 (19.7%) cases had SLN biopsy. The incidence of micrometastasis was significantly higher in the SLN biopsy group compared to the lymphadenectomy group (8.4% versus 5.0%, odds ratio 1.74, 95% confidence interval 1.06-2.86, P = 0.028). In T2 disease (SLN biopsy in 57 [13.0%] of 437 cases), the incidence of micrometastasis was similar between the two groups (7.9% versus 7.0%, odds ratio 0.88, 95% confidence interval 0.30-2.60, P = 0.818).

CONCLUSION

This study suggests that SLN biopsy protocol may identify more micrometastasis in the regional lymph nodes of T1 endometrial cancer. Whether national-level increase in the utilization of SLN biopsy for early endometrial cancer results in a stage-shifting to advanced disease on a population-basis warrants further investigation.

Evaluating long-term outcomes of three approaches to retroperitoneal staging in endometrial cancer

OBJECTIVE

Sentinel lymph node mapping (SNM) has gained popularity in managing apparent early-stage endometrial cancer (EC). Here, we evaluated the long-term survival of three different approaches of nodal assessment.

METHODS

This is a multi-institutional retrospective study evaluating long-term outcomes of EC patients having nodal assessment between 01/01/2006 and 12/31/2016. In order to reduce possible confounding factors, we applied a propensity-matched algorithm.

RESULTS

Overall, 940 patients meeting inclusion criteria were included in the study, of which 174 (18.5%), 187 (19.9%), and 579 (61.6%) underwent SNM, SNM followed by backup lymphadenectomy (LND) and LND alone, respectively. Applying a propensity score matching algorithm (1:1:2) we selected 500 patients, including 125 SNM, 125 SNM/backup LND, and 250 LND. Baseline characteristics of the study population were similar between groups. The prevalence of nodal disease was 14%, 16%, and 12% in patients having SNM, SNM/backup LND and LND, respectively. Overall, 19 (7.6%) patients were diagnosed with low volume nodal disease. The survival analysis comparing the three techniques did not show statistical differences in terms of disease-free (p = 0.750) and overall survival (p = 0.899). Similarly, the type of nodal assessment did not impact survival outcomes after stratification based on uterine risk factors.

CONCLUSION

Our study highlighted that SNM provides similar long-term oncologic outcomes than LND.