Implementing a Cervical Sentinel Lymph Node Biopsy Program: Quality Improvement in Gynaecologic Oncology

Association Study between the Sentinel Lymph Node Biopsy and the Clinicopathological Features of Patients with Cervical Cancer

Objective

The incidence of cervical cancer is increasing year by year, which seriously threatens the health of female patients. This study is aimed at investigating the association of sentinel lymph node biopsy (SLNB) with clinicopathological features in cervical cancer patients.

Methods

Patients diagnosed with cervical cancer in our hospital from February 1, 2019, to June 30, 2021, were selected as the research subjects. Statistical analysis was performed on the SLN examination of patients with cervical cancer with different pathological characteristics and the correlation between the positive rate of SLN detection and the pathological characteristics of cervical cancer.

Results

A total of 59 patients with cervical cancer were included in this study, the SLNB detection rate was 94.92%, 15 patients had lymph node metastasis, and the metastasis rate was 25.42% confirmed by histopathology. Thirteen of them had SLN metastases, and the other 2 had non-SLN metastases. The sensitivity of SLNB was 86.67%, and the false negative rate was 13.33%. Statistical analysis results showed that there was no significant difference in the positive rate of SLN among cervical cancer patients with different FIGO stages, pathological types, degree of differentiation, depth of invasion, and tumor size. In addition, the results of Pearson's correlation analysis showed that the positive rate of SLN was not significantly correlated with the FIGO stage, pathological type, degree of differentiation, depth of invasion, and tumor size of cervical cancer.

Conclusion

SLNB has a high sensitivity, safety, and feasibility in the diagnosis and evaluation of lymph node metastasis in cervical cancer. There is no significant correlation between SLNB and the clinicopathological features of cervical cancer.

Sentinel node navigation surgery in cervical cancer: a systematic review and metaanalysis

Sentinel node navigation surgery (SNNS) is used in clinical practice for the treatment of cervical cancer. This study aimed to elucidate the appropriate sentinel lymph node (SLN) mapping method and assess the safety and benefits of SNNS. We searched the PubMed, Ichushi, and Cochrane Library databases for randomized controlled trials (RCT) and studies on SLN in cervical cancer from January 2012 to December 2020. Two authors independently assessed study quality and extracted data. We quantitatively analyzed the detection rate, sensitivity/specificity, and complications and reviewed information, including the survival data of SLN biopsy (SLNB) without pelvic lymphadenectomy (PLND). The detection rate of SLN mapping in the unilateral pelvis was median 95.7% and 100% and in the bilateral pelvis was median 80.4% and 90% for technetium-99 m (Tc) with/without blue dye (Tc w/wo BD) and indocyanine green (ICG) alone, respectively. The sensitivity and specificity of each tracer were high; the area under the curve of each tracer was 0.988 (Tc w/wo BD), 0.931 (BD w/wo Tc), 0.966 (ICG), and 0.977 (carbon nanoparticle). Morbidities including lymphedema, neurological symptoms and blood loss were associated with PLND. One RCT and five studies all showed SNNS without systematic PLND does not impair recurrence or survival in early-stage cervical cancer with a tumor size ≤ 2-4 cm. Both Tc w/wo BD and ICG are appropriate SLN tracers. SNNS can reduce the morbidities associated with PLND without affecting disease progression in early-stage cervical cancer.

Sentinel Lymph Node Mapping in High-Grade Endometrial Cancer

Sentinel lymph node (SLN) mapping is becoming an acceptable alternative to full lymphadenectomy for evaluating lymphatic spread in clinical stage I endometrial cancer (EC). While the assessment of pelvic and para-aortic lymph nodes is part of the surgical staging of EC, there is a long-standing debate over the therapeutic value of full lymphadenectomy in this setting. Although lymphadenectomy offers critical information on lymphatic spread and prognosis, most patients will not derive oncologic benefit from this procedure as the majority of patients do not have lymph node involvement. SLN mapping offers prognostic information while simultaneously avoiding the morbidity associated with an extensive and often unnecessary lymphadenectomy. A key factor in the decision making when planning for EC surgery is the histologic subtype. Since the risk of lymphatic spread is less than 5% in low-grade EC, these patients might not benefit from lymph node assessment. Nonetheless, in high-grade EC, the risk for lymph node metastases is much higher (20–30%); therefore, it is crucial to determine the spread of disease both for determining prognosis and for tailoring the appropriate adjuvant treatment. Studies on the accuracy of SLN mapping in high-grade EC have shown a detection rate of over 90%. The available evidence supports adopting the SLN approach as an accurate method for surgical staging. However, there is a paucity of prospective data on the long-term oncologic outcome for patients undergoing SLN mapping in high-grade EC, and more trials are warranted to answer this question.

Sentinel lymph node biopsy in high-grade endometrial cancer: a systematic review and meta-analysis of performance characteristics

OBJECTIVE

A sentinel lymph node biopsy is widely accepted as the standard of care for surgical staging in low-grade endometrial cancer, but its value in high-grade endometrial cancer remains controversial. The aim of this systematic review and meta-analysis was to evaluate the performance characteristics of sentinel lymph node biopsy in patients with endometrial cancer with high-grade histology (registered in the International Prospective Register of Systematic Reviews with identifying number CRD42020160280).

DATA SOURCES

We systematically searched the MEDLINE, Epub Ahead of Print, MEDLINE In-Process & Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Embase databases all through the OvidSP platform. The search was performed between January 1, 2000, and January 26, 2021. ClinicalTrials.gov was searched to identify ongoing registered clinical trials.

STUDY ELIGIBILITY CRITERIA

We included prospective cohort studies in which sentinel lymph node biopsy were evaluated in clinical stage I patients with high-grade endometrial cancer (grade 3 endometrioid, serous, clear cell, carcinosarcoma, mixed, undifferentiated or dedifferentiated, and high-grade not otherwise specified) with a cervical injection of indocyanine green for sentinel lymph node detection and at least a bilateral pelvic lymphadenectomy as a reference standard. If the data were not reported specifically for patients with high-grade histology, the authors were contacted for aggregate data.

METHODS

We pooled the detection rates and measures of diagnostic accuracy using a generalized linear mixed-effects model with a logit and assessed the risk of bias using the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

RESULTS

We identified 16 eligible studies of which the authors for 9 of the studies provided data on 429 patients with high-grade endometrial cancer specifically. The study-level median age was 66 years (range, 44-82.5 years) and the study-level median body mass index was 28.6 kg/m² (range, 19.4-43.7 kg/m²). The pooled detection rates were 91% per patient (95% confidence interval, 85%-95%; I²=59%) and 64% bilaterally (95% confidence interval, 53%-73%; I²=69%). The overall node positivity rate was 26% (95% confidence interval, 19%-34%; I²=44%). Of the 87 patients with positive node results, a sentinel lymph node biopsy correctly identified 80, yielding a pooled sensitivity of 92% per patient (95% confidence interval, 84%-96%; I²=0%), a false negative rate of 8% (95% confidence interval, 4%-16%; I²=0%), and a negative predictive value of 97% (95% confidence interval, 95%-99%; I²=0%).

CONCLUSION

Sentinel lymph node biopsy accurately detect lymph node metastases in patients with high-grade endometrial cancer with a false negative rate comparable with that observed in low-grade endometrial cancer, melanoma, vulvar cancer, and breast cancer. These findings suggest that sentinel lymph node biopsy can replace complete lymphadenectomies as the standard of care for surgical staging in patients with high-grade endometrial cancer.

Development of a surgical competency assessment tool for sentinel lymph node dissection by minimally invasive surgery for endometrial cancer

INTRODUCTION

Sentinel lymph node dissection is widely used in the staging of endometrial cancer. Variation in surgical techniques potentially impacts diagnostic accuracy and oncologic outcomes, and poses barriers to the comparison of outcomes across institutions or clinical trial sites. Standardization of surgical technique and surgical quality assessment tools are critical to the conduct of clinical trials. By identifying mandatory and prohibited steps of sentinel lymph node (SLN) dissection in endometrial cancer, the purpose of this study was to develop and validate a competency assessment tool for use in surgical quality assurance.

METHODS

A Delphi methodology was applied, included 35 expert gynecological oncology surgeons from 16 countries. Interviews identified key steps and tasks which were rated mandatory, optional, or prohibited using questionnaires. Using the surgical steps for which consensus was achieved, a competency assessment tool was developed and subjected to assessments of validity and reliability.

RESULTS

Seventy percent consensus agreement standardized the specific mandatory, optional, and prohibited steps of SLN dissection for endometrial cancer and informed the development of a competency assessment tool. Consensus agreement identified 21 mandatory and three prohibited steps to complete a SLN dissection. The competency assessment tool was used to rate surgical quality in three preselected videos, demonstrating clear separation in the rating of the skill level displayed with mean skills summary scores differing significantly between the three videos (F score=89.4; P<0.001). Internal consistency of the items was high (Cronbach α=0.88).

CONCLUSION

Specific mandatory and prohibited steps of SLN dissection in endometrial cancer have been identified and validated based on consensus among a large number of international experts. A competency assessment tool is now available and can be used for surgeon selection in clinical trials and for ongoing, prospective quality assurance in routine clinical care.

Assessment of Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging

Question

What is the diagnostic accuracy of sentinel lymph node biopsy (SLNB) compared with lymphadenectomy in women with intermediate- and high-grade endometrial cancer?

Findings

In this cohort study of 156 patients with endometrial cancer (126 with high-grade histologic subtypes), SLNB had a sensitivity of 96% and a negative predictive value of 99% for the detection of nodal metastasis. A total of 26% of patients with node-positive cancer were identified outside lymphadenectomy boundaries or required immunohistochemistry for diagnosis.

Meaning

In this study, SLNB had similar diagnostic accuracy and prognostic ability as lymphadenectomy in patients with high-grade endometrial cancer at greatest risk for nodal metastasis.

Importance

Whether sentinel lymph node biopsy (SLNB) can replace lymphadenectomy for surgical staging in patients with high-grade endometrial cancer (EC) is unclear.

Objective

To examine the diagnostic accuracy of, performance characteristics of, and morbidity associated with SLNB using indocyanine green in patients with intermediate- and high-grade EC.

Design, Setting, and Participants

In this prospective, multicenter cohort study (Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging [SENTOR] study), accrual occurred from July 1, 2015, to June 30, 2019, with early stoppage because of prespecified accuracy criteria. The study included patients with clinical stage I grade 2 endometrioid or high-grade EC scheduled to undergo laparoscopic or robotic hysterectomy with an intent to complete staging at 3 designated cancer centers in Toronto, Ontario, Canada.

Exposures

All patients underwent SLNB followed by lymphadenectomy as the reference standard. Patients with grade 2 endometrioid EC underwent pelvic lymphadenectomy (PLND) alone, and patients with high-grade EC underwent PLND and para-aortic lymphadenectomy (PALND).

Main Outcomes and Measures

The primary outcome was sensitivity of the SLNB algorithm. Secondary outcomes were additional measures of diagnostic accuracy, sentinel lymph node detection rates, and adverse events.

Results

The study enrolled 156 patients (median age, 65.5 years; range, 40-86 years; median body mass index [calculated as weight in kilograms divided by height in meters squared], 27.5; range, 17.6-49.3), including 126 with high-grade EC. All patients underwent SLNB and PLND, and 101 patients (80%) with high-grade EC also underwent PALND. Sentinel lymph node detection rates were 97.4% per patient (95% CI, 93.6%-99.3%), 87.5% per hemipelvis (95% CI, 83.3%-91.0%), and 77.6% bilaterally (95% CI, 70.2%-83.8%). Of 27 patients (17%) with nodal metastases, 26 patients were correctly identified by the SLNB algorithm, yielding a sensitivity of 96% (95% CI, 81%-100%), a false-negative rate of 4% (95% CI, 0%-19%), and a negative predictive value of 99% (95% CI, 96%-100%). Only 1 patient (0.6%) was misclassified by the SLNB algorithm. Seven of 27 patients with node-positive cancer (26%) were identified outside traditional PLND boundaries or required immunohistochemistry for diagnosis.

Conclusions and Relevance

In this prospective cohort study, SLNB had acceptable diagnostic accuracy for patients with high-grade EC at increased risk of nodal metastases and improved the detection of node-positive cases compared with lymphadenectomy. The findings suggest that SLNB is a viable option for the surgical staging of EC.

Survival after minimally invasive surgery in early cervical cancer: is the intra-uterine manipulator to blame?

Objectives

Minimally invasive radical hysterectomy is associated with decreased survival in patients with early cervical cancer. The objective of this study was to determine whether the use of an intra-uterine manipulator at the time of laparoscopic or robotic radical hysterectomy is associated with inferior oncologic outcomes.

Methods

A retrospective cohort study was carried out of all patients with cervical cancer (squamous cell carcinoma, adenocarcinoma or adenosquamous carcinoma) International Federation of Gynecology and Obstetrics 2009 stages IA1 (with positive lymphovascular space invasion) to IIA who underwent minimally invasive radical hysterectomy at two academic centers between January 2007 and December 2017. Treatment, tumor characteristics, and survival data were retrieved from hospital records.

Results

A total of 224 patients were identified at the two centers; 115 had surgery with the use of an intra-uterine manipulator while 109 did not; 53 were robotic and 171 were laparoscopic. Median age was 44 years (range 38–54) and median body mass index was 25.8 kg/m2 (range 16.6–51.5). Patients in whom an intra-uterine manipulator was not used at the time of minimally invasive radical hysterectomy were more likely to have residual disease at hysterectomy (p<0.001), positive lymphovascular space invasion (p=0.02), positive margins (p=0.008), and positive lymph node metastasis (p=0.003). Recurrence-free survival at 5 years was 80% in the no intra-uterine manipulator group and 94% in the intra-uterine manipulator group. After controlling for the presence of residual cancer at hysterectomy, tumor size and high-risk pathologic criteria (positive margins, parametria or lymph nodes), the use of an intra-uterine manipulator was no longer significantly associated with worse recurrence-free survival (HR 0.4, 95% CI 0.2 to 1.0, p=0.05). The only factor which was consistently associated with recurrence-free survival was tumor size (HR 2.1, 95% CI 1.5 to 3.0, for every 10 mm increase, p<0.001).

Conclusion

After controlling for adverse pathological factors, the use of an intra-uterine manipulator in patients with early cervical cancer who underwent minimally invasive radical hysterectomy was not an independent factor associated with rate of recurrence.

Pathologic Protocols for Sentinel Lymph Nodes Ultrastaging in Cervical Cancer

CONTEXT.—

Ultrastaging of sentinel lymph nodes (SLNs) is a crucial aspect in the approach to SLN processing. No consensual protocol for pathologic ultrastaging has been approved by international societies to date.

OBJECTIVE.—

To provide a review of the ultrastaging protocol and all its aspects related to the processing of SLNs in patients with cervical cancer.

DATA SOURCES.—

In total, 127 publications reporting data from 9085 cases were identified in the literature. In 24% of studies, the information about SLN processing is entirely missing. No ultrastaging protocol was used in 7% of publications. When described, the differences in all aspects of SLN processing among the studies and institutions are substantial. This includes grossing of the SLN, which is not completely sliced and processed in almost 20% of studies. The reported protocols varied in all aspects of SLN processing, including the thickness of slices (range, 1-5 mm), the number of levels (range, 0-cut out until no tissue left), distance between the levels (range, 40-1000 μm), and number of sections per level (range, 1-5).

CONCLUSIONS.—

We found substantial differences in protocols used for SLN pathologic ultrastaging, which can impact sensitivity for detection of micrometastases and even small macrometastases. Since the involvement of pelvic lymph nodes is the most important negative prognostic factor, such profound discrepancies influence the referral of patients to adjuvant radiotherapy and could potentially cause treatment failure. It is urgent that international societies agree on a consensual protocol before SLN biopsy without pelvic lymphadenectomy is introduced into routine clinical practice.

Does small volume metastatic lymph node disease affect long-term prognosis in early cervical cancer?

INTRODUCTION

As sentinel lymph node biopsy is evolving to an accepted standard of care, clinicians are being faced with more frequent cases of small volume nodal metastatic disease. The objective of this study is to describe the management and to measure the effect on recurrence rates of nodal micrometastasis and isolated tumor cells in patients with early stage cervical cancer at two high-volume centers.

METHODS

We conducted a review of prospectively collected patients with surgically treated cervical cancer who were found to have micrometastasis or isolated tumor cells on ultrastaging of the sentinel lymph node. Our practice is to follow patients for ≥5 years post-operatively either at our center or another cancer center closer to home.

RESULTS

Nineteen patients with small volume nodal disease were identified between 2006 and 2018. Median follow-up was 62 months. Ten (53%) had nodal micrometastatic disease, while nine (47%) had isolated tumor cells detected in the sentinel lymph node. Seven patients (37%) underwent completion pelvic lymphadenectomy and four of them also had para-aortic lymphadenectomy; there were no positive non-sentinel lymph nodes. The majority (74%) received adjuvant treatment, mostly driven by tumor factors. We observed two recurrences. Recurrence-free survival was comparable with historical cohorts of node negative patients, and adjuvant treatment did not seem to impact the recurrence rate (p=0.5).

CONCLUSION

Given the uncertainties around the prognostic significance of small volume nodal disease in cervical cancer, a large proportion of patients receive adjuvant treatment. We found no positive non-sentinel lymph nodes, suggesting that pelvic lymphadenectomy or para-aortic lymphadenectomy may not be of benefit in patients diagnosed with small volume nodal metastases. Recurrence-free survival in this group did not seem to be affected. However, given the small numbers of patients and lack of level 1 evidence, decisions should be individualized in accordance with patient preferences and tumor factors.