Establishing a sentinel lymph node mapping algorithm for the treatment of early cervical cancer

Treatment advances across the cervical cancer spectrum

Cervical cancer is preventable with screening and vaccination approaches; however, access to these preventative measures is limited both nationally and globally and thus many women will still develop cervical cancer. Novel treatments and practice-changing research have improved cervical cancer outcomes over the past few decades. In this Review, we discuss clinical trials that have refined or redefined the treatment of cervical cancers across the early stage, locally advanced, persistent, recurrent and/or metastatic disease settings. Advances for patients with early stage disease have been achieved through trials evaluating less extensive and fertility-preserving surgeries, different surgical approaches (open versus minimally invasive), and sentinel versus full pelvic lymph node dissection. We also discuss results from trials testing the use of neoadjuvant, induction and adjuvant chemotherapy as well as immune-checkpoint inhibitors in patients with locally advanced disease. Finally, we review the progress made with systemic chemotherapy and novel therapeutics, including anti-angiogenic agents, immune-checkpoint inhibitors and antibody-drug conjugates, in the setting of metastatic and/or recurrent cervical cancer. The advances highlighted in this manuscript have reduced morbidity and improved overall survival for patients with this challenging-to-treat disease, while also inspiring additional research and trials in the field.

Comparison of clinical outcomes in women with surgically treated early primary cervical cancer: Lymphadenectomy vs sentinel lymph node biopsy

BACKGROUND

The primary objective of this study was to elucidate the impact of sentinel lymph node (SLN) mapping and biopsy techniques on the clinical outcomes of women with early primary cervical cancer.

METHODS

All consecutive women with clinically determined stage I-IIA cervical cancer who underwent lymph node assessment with either SLN mapping or conventional pelvic/para-aortic lymphadenectomy were reviewed.

RESULTS

Women in the SLN group (n = 33) had fewer total dissected pelvic nodes (8.3 ± 5.9 vs 17.4 ± 7.7, p < 0.001), less intraoperative blood loss (513 ± 332 vs 1228 ± 1170 mL, p < 0.001), a shorter length of hospital stay (7.1 ± 2.4 vs 10.2 ± 6.1 days, p = 0.004) than women in the conventional lymphadenectomy group (n = 74). The rates of recurrence-free survival (3-year: 87.6% vs 82.9%) and overall survival (3-year: 100% vs 91.0%) did not differ between the SLN group and the conventional lymphadenectomy group ( p = 0.846 and p = 0.254, respectively).

CONCLUSION

SLN biopsy does not seem to be associated with an inferior survival outcome compared with conventional lymphadenectomy in women with early primary cervical cancer. In addition, it is associated with less blood loss and a shorter length of hospital stay.

Sentinel lymph node detection with indocyanine green and patent blue dye in cervical cancer: A single-centre feasibility study

BACKGROUND

Sentinel lymph node (SLN) dissection has been established as standard of care in many tumours. Its use in early cervical cancer is an area of increasing interest and some studies suggest a high detection rate.

AIM

To explore feasibility of SLN dissection and establish the patient detection rate in women with early cervical cancer.

MATERIALS AND METHODS

All patients with early cervical cancer, International Federation of Gynaecology and Obstetrics (FIGO) 2018 Stage 1, of any histology who underwent SLN dissection from January 2017 to March 2023 were included. Patients were eligible if they had pelvic confined disease; no suspicious lymph nodes on pre-operative imaging or intra-operatively; tumours <4 cm at the time of surgery and no contra-indications to surgery. Patients were excluded if there was a known allergy to dye or less than six months follow-up data.

RESULTS

Sixty-two patients were included in the study and 53% had FIGO stage 1b1 disease. The overall bilateral SLN detection rate was 89%, and the side-specific rate was 94%. Where indocyanine green (ICG) was used alone, the bilateral detection rate was 87% and the side-specific rate was 93%. Where ICG was used with patent blue dye (PTB) the bilateral detection rate was 92% and the side-specific rate was 96%. Where PTB was used alone the bilateral detection rate was 85% and the side-specific rate was 92%. The node positive rate was 6% (7/124) which included isolated tumour cells in four patients.

CONCLUSION

SLN dissection with ICG or PTB is feasible in early-stage cervical cancer.

Lymph node assessment in cervical cancer: current approaches

Cervical cancer (CC) is the fourth most common neoplasia in women worldwide. Although early-stage CC is often curable, 40 to 50% of patients are diagnosed at a locally advanced stage. Metastatic disease accounts for the principal cause of death. Lymph node (LN) status is a major factor impacting treatment options and prognosis. Historically, CC was staged based only on clinical findings. However, in 2018, imaging modalities and/or pathological findings were included in the International Federation of Gynecology and Obstetrics (FIGO) staging classification. In the last decades, LN status assessment has evolved considerably. Full pelvic lymphadenectomy used to be the only way to determine LN status. Currently, several options exist: surgery with full lymphadenectomy, sentinel lymph node (SLN) biopsy or imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). Regarding surgery, the SLN biopsy technique has become a standard procedure in cases of CC, with indocyanine green (ICG) being the preferred dye. Pelvic MRI is a valuable imaging technique modality for the evaluation of pelvic LNs. In locally advanced or in early-stage disease with suspicious LNs on CT scans or MRI, PET/CT is recommended for assessment of nodal and distant status. The best strategy for LN assessment remains a highly controversial topic in the literature. In this article, we aim to review and compare the advantages and limitations of each modality, i.e. imaging or surgical (lymphadenectomy or SLN biopsy) approaches.

Benefits of sentinel node detection in cervical cancer

PURPOSE OF REVIEW

Sentinel lymph node biopsy (SLNB) is a widely used technique in other gynaecological tumours but has not yet been implemented as the gold standard technique for nodal staging in cervical cancer. Since the majority of evidence is derived from retrospective studies, this review aims to summarize the most recent evidence on this relevant topic.

RECENT FINDINGS

SLNB has demonstrated to be a well tolerated technique for lymph node staging in early-stage cervical cancer patients with promising future as exclusive lymph node assessment method avoiding full lymphadenectomy. Moreover, it allows ultrastaging and unfrequent drainage identification, which enables the detection of patients at a high risk of recurrence who would otherwise remain unnoticed. When compared with pelvic lymphadenectomy, SLNB is also associated with less intraoperative and postoperative complications, especially in terms of lymphedema formation.

SUMMARY

The available evidence suggests that SLNB offers numerous advantages over the standard pelvic lymphadenectomy reducing morbidity rates and increasing diagnostic accuracy. Three ongoing prospective trials will likely answer the controversies over these questions.

A prospective study evaluating an optimized sentinel node algorithm in early stage cervical cancer: The PROSACC-study

OBJECTIVE

A single center prospective non-randomized study to assess a systematically developed anatomically-based sentinel lymph node (SLN) algorithm in cervical cancer.

METHODS

Consecutive women with FIGO 2009 stage 1A2-2A1 cervical cancer undergoing robotic radical hysterectomy/trachelectomy between September 2014 and January 2023 had cervically injected Indocyanine Green (ICG) as a tracer for detection of pelvic SLN. An anatomically based surgical algorithm was adhered to; defining SLNs as the juxtauterine mapped nodes within the upper and lower paracervical lymphatic pathways including separate removal of the parauterine lymphovascular tissue (PULT). A completion pelvic lymphadenectomy was performed. Ultrastaging and immunohistochemistry was performed on SLNs, including the PULT.

RESULTS

181 women were included for analysis. Median histologic tumor size was 14.0 mm (range 2-80 mm). The bilateral mapping rate was 98.3%. As per protocol an interim analysis rejected H0 and inclusion stopped at 29 node positive women, all identified by at least one metastatic ICG-defined SLN. One woman awaiting histology at study-closure was node positive and included in the analysis. Sensitivity was 100% (95% CI, 88.4%-100%) and NPV 100% (95% CI, 97.6%-100%). In node positive women, the proximal obturator position harbored 46.1% of all SLN metastases representing the only position in 40% and 10% had isolated metastases in the PULT.

CONCLUSIONS

Strictly adhering to an anatomically based SLN-algorithm including identification of parallell lymphatics within major pathways, partilularly the obturator compartment, assessment of the PULT, restricting nodal dissection to the removal of SLNs accurately identifies pelvic nodal metastatic disease in early-stage cervical cancer.

The Polish Society of Gynecological Oncology Guidelines for the Diagnosis and Treatment of Cervical Cancer (v2024.0)

Background: Recent publications underscore the need for updated recommendations addressing less radical surgery for <2 cm tumors, induction chemotherapy, or immunotherapy for locally advanced stages of cervical cancer, as well as for the systemic therapy for recurrent or metastatic cervical cancer. Aim: To summarize the current evidence for the diagnosis, treatment, and follow-up of cervical cancer and provide evidence-based clinical practice recommendations. Methods: Developed according to AGREE II standards, the guidelines classify scientific evidence based on the Agency for Health Technology Assessment and Tariff System criteria. Recommendations are graded by evidence strength and consensus level from the development group. Key Results: (1) Early-Stage Cancer: Stromal invasion and lymphovascular space involvement (LVSI) from pretreatment biopsy identify candidates for surgery, particularly for simple hysterectomy. (2) Surgical Approach: Minimally invasive surgery is not recommended, except for T1A, LVSI-negative tumors, due to a reduction in life expectancy. (3) Locally Advanced Cancer: concurrent chemoradiation (CCRT) followed by brachytherapy (BRT) is the cornerstone treatment. Low-risk patients (fewer than two metastatic nodes or FIGO IB2-II) may consider induction chemotherapy (ICT) followed by CCRT and BRT after 7 days. High-risk patients (two or more metastatic nodes or FIGO IIIA, IIIB, and IVA) benefit from pembrolizumab with CCRT and maintenance therapy. (4) Metastatic, Persistent, and Recurrent Cancer: A PD-L1 status from pretreatment biopsy identifies candidates for Pembrolizumab with available systemic treatment, while triplet therapy (Atezolizumab/Bevacizumab/chemotherapy) becomes a PD-L1-independent option. Conclusions: These evidence-based guidelines aim to improve clinical outcomes through precise treatment strategies based on individual risk factors, predictors, and disease stages.

Detecting Atypical Sentinel Lymph Nodes in Early-Stage Cervical Cancer Using a Standardized Technique with a Hybrid Tracer

BACKGROUND

Since October 2018, lymph node status has become part of the FIGO staging, given that it is one of the most important prognostic factors among women with CC. The aim was to determine the rate of atypical lymphatic drainage in patients with clinical early-stage cervical cancer using a hybrid tracer (ICG-99mTc nanocolloid).

METHODOLOGY

A prospective, observational, single-centre study conducted at Son Espases University Hospital between January 2019 and October 2023. Patients with clinical early-stage CC who underwent SLN mapping were included. External iliac and obturator nodes were defined as common locations. Para-aortic, common iliac, presacral, internal iliac, and parametrial nodes were defined as atypical locations.

RESULTS

Thirty-nine cases of CC were included. The overall SLN detection rate was 97.4%, with 89.5% bilaterally. Positive nodes were found in 21.1% of patients. Atypical lymphatic drainage was present in 8 out of 38 (21.1%) patients. Of all the SLNs biopsied (146), 10.3% corresponded to an atypical zone. SLN in the atypical area had a higher proportion of metastasis than the usual area (37.5% vs. 16.7%; p = 0.327).

CONCLUSIONS

SLN biopsy can detect unusual drainage in a significant proportion of patients. Atypical lymph nodes have a higher percentage of metastasis, which consequently improves staging and tailoring therapy. SLN mapping performed via a standardized surgical technique using a hybrid tracer (ICG-99mTc) could help in the identification of the "true SLN".

Mexican consensus about surgical treatment in early-stage cervicouterine cancer

Introduction

Cervical cancer is a public health problem in our country and worldwide. Less than 25% of cases are diagnosed in the early stages, where survival is more remarkable than 90% at five years. Here, we review surgical treatment in the early stages of cervical cancer.

Methodology

A literature review was carried out in the MEDLINE database. The search was mainly limited to the English language, with priority given to systematic reviews with or without meta-analysis and randomized studies. However, only retrospective or observational evidence was found for some topics.

Results

The standard treatment for early-stage cervical cancer is hysterectomy, and its radical nature will depend on the tumor size, lymphovascular permeation, and tumor-specific prognostic factors. Furthermore, the type of surgery (hysterectomy or trachelectomy) will rely on the patient's desire to preserve fertility. Nodal evaluation is indicated as part of the treatment from stage IAI with PLV. However, the sentinel lymph node is more relevant in the treatment. The incidental finding of cervical cancer after a hysterectomy requires a multidisciplinary evaluation to determine the therapeutic approach. Less radical surgery has been described as oncologically safe in low-risk groups.

Conclusion

Surgical treatment in its early stages has evolved in recent decades, making it more individualized and seeking less morbidity in patients without compromising their survival.

Sentinel Lymph Node Mapping by Retroperitoneal vNOTES for Uterus-Confined Malignancies: A Standardized 10-Step Approach

(1) Background: Sentinel lymph node (SLN) mapping represents an accurate and feasible technique for the surgical staging of endometrial and cervical cancer. This is commonly performed by conventional laparoscopy or robotic-assisted laparoscopy, but in recent years, a new retroperitoneal transvaginal natural orifice transluminal endoscopic surgery (vNOTES) approach has been described and developed by Jan Baekelandt. This technique provides easy visualization of lymphatic afferent vessels and pelvic lymph nodes, early SLN assessment, and a coherent mapping methodology following the lymphatic flow from caudal to cranial. However, only a few publications have reported it. Following the IDEAL (Idea Development Exploration Assessment Long-term follow-up) framework, research concerning this technique is in Stage 2a, with only small case series as evidence of its feasibility. Its standardized description appears necessary to provide the surgical homogeneity required to move further. (2) Methods: Description of a standardized approach for retroperitoneal pelvic SLN mapping by vNOTES. (3) Results: We describe a 10-step approach to successfully perform retroperitoneal vNOTES SLN mapping, including pre-, intra-, and postoperative management. (4) Conclusions: This IDEAL Stage 2a study could help other surgeons approach this new technique, and it proposes a common methodology necessary for evolving through future IDEAL Stage 2b (multi-center studies) and Stage 3 (randomized controlled trials) studies.

A machine learning-based prediction model of pelvic lymph node metastasis in women with early-stage cervical cancer

OBJECTIVE

To develop a novel machine learning-based preoperative prediction model for pelvic lymph node metastasis (PLNM) in early-stage cervical cancer by combining the clinical findings and preoperative computerized tomography (CT) of the whole abdomen and pelvis.

METHODS

Patients diagnosed with International Federation of Gynecology and Obstetrics stage IA2-IIA1 squamous cell carcinoma, adenocarcinoma, and adenosquamous carcinoma of the cervix who had primary radical surgery with bilateral pelvic lymphadenectomy from January 1, 2003 to December 31, 2020, were included. Seven supervised machine learning algorithms, including logistic regression, random forest, support vector machine, adaptive boosting, gradient boosting, extreme gradient boosting, and category boosting, were used to evaluate the risk of PLNM.

RESULTS

PLNM was found in 199 (23.9%) of 832 patients included. Younger age, larger tumor size, higher stage, no prior conization, tumor appearance, adenosquamous histology, and vaginal metastasis as well as the CT findings of larger tumor size, parametrial metastasis, pelvic lymph node enlargement, and vaginal metastasis, were significantly associated with PLNM. The models' predictive performance, including accuracy (89.1%-90.6%), area under the receiver operating characteristics curve (86.9%-91.0%), sensitivity (77.4%-82.4%), specificity (92.1%-94.3%), positive predictive value (77.0%-81.7%), and negative predictive value (93.0%-94.4%), appeared satisfactory and comparable among all the algorithms. After optimizing the model's decision threshold to enhance the sensitivity to at least 95%, the 'highly sensitive' model was obtained with a 2.5%-4.4% false-negative rate of PLNM prediction.

CONCLUSION

We developed prediction models for PLNM in early-stage cervical cancer with promising prediction performance in our setting. Further external validation in other populations is needed with potential clinical applications.

Clinical outcomes of sentinel node navigation surgery in patients with preoperatively estimated stage IA endometrial cancer and evaluation of validity for continuing sentinel node navigation surgery based on dispersion of recurrence probability

BACKGROUND

To evaluate the feasibility of the use and continuation of sentinel lymph node navigation surgery (SNNS) as an alternative to pelvic lymph node dissection (PLND) for patients with preoperatively estimated stage IA endometrial cancer.

METHODS

This retrospective study selected the electronic medical records of all patients who had received CT scans and MRI imaging before surgery from April 1, 2009 to March 31, 2021. Sentinel lymph nodes (SLNs) were detected by administrating 99mTc-phytate and/or indocyanine green into the cervix, and the clinical outcomes of the patients who underwent SNNS or PLND were evaluated. Furthermore, in case of nodal recurrence, a new procedure to determine whether the facility should continue with SNNS or not was developed that compares the maximum likelihood hypothesis and an alternative one based on recurrence rates.

RESULTS

Among 137 patients, SLN biopsies with ultrastaging were performed on 91 patients. The SLN detection rate was 95.6%. Over a 59-month median observation period, no statistically significant differences were shown in overall survival, disease-specific survival and disease-free survival between the SNNS and PLND groups when introducing the propensity score method (p-values: 0.06, 0.153, and 0.625, respectively). Our procedure demonstrated that, in our department without recurrence up to the 65th attempt, it was possible to continue SNNS if a recurrence occurs at the 66th attempt.

CONCLUSION

This study suggests the validity of SNNS as an alternative to PLND. Even in the absence of evidence from randomized controlled trials, we can confirm the validity of continuing SNNS using our procedure.

Sentinel lymph node mapping with indocyanine green using SPY-PHI in open radical hysterectomy or trachelectomy

OBJECTIVE

To evaluate the detection rate of at least one sentinel lymph node (SLN) in patients with early cervical cancer who underwent open radical hysterectomy or trachelectomy using indocyanine green (ICG) with the SPY Portable Handler Imager (SPY-PHI) system.

METHODS

We retrospectively reviewed patients with cervical cancer FIGO 2018 stage IA1 with lymphovascular invasion up to stage IIIC1p who underwent SLN mapping and open radical hysterectomy or trachelectomy from March 2018 through August 2022 at The University of Texas MD Anderson Cancer Center. ICG was the only tracer used with the SPY-PHI system. Patient demographics, surgical approach, and tumor factors were analyzed. Overall detection, bilateral detection, and empty lymph node packet rates were determined.

RESULTS

A total of 106 patients were included. Ninety-four (88.7%) patients underwent open radical hysterectomy and 12 (11.3%) open radical trachelectomy. Median age was 40 years (range, 23-71). Median body mass index was 28.8 kg/m2 (range, 17.6-48.4). The most common FIGO 2018 stages were IB1 (35%) and IB2 (30%). The most common histologic subtypes were squamous cell carcinoma (45%) and adenocarcinoma (45%). Most patients had grade 2 disease (61%) and no lymphovascular invasion (58%). Median tumor size was 1.8 cm (range, 0.3-4). Median number of detected SLN was 4 (range, 0-12). An SLN was identified during surgery in 104 patients (98%), with bilateral mapping in 94 (89%) and unilateral mapping in 10 (9%). The empty lymph node packet rate was 4 (3.8%). The external iliac (73%) was the most common site of SLN detection. Fourteen patients had positive lymph nodes (13.5%); 3 (21.4%) had macrometastases, 9 (64.3%) had micrometastases, and 2 (14.3%) had isolated tumor cells.

CONCLUSION

SLN mapping using ICG with the SPY-PHI system in open radical hysterectomy or trachelectomy is reliable and results in high overall and bilateral detection rates in patients with early cervical cancer.

A SPECT/NIR Fluorescence Dual-Modality Imaging Agent Composed of Drugs and Hospital Available Isotope for Preoperative Sentinel Lymph Node Mapping and Intraoperative Biopsy

BACKGROUND

Sentinel lymph node (SLN) mapping-guided biopsy is crucial for cancer staging and treatment. Optical/nuclide dual-modality imaging agents for mapping SLN are ideal for preoperative planning and intraoperative biopsy, which are enabled by penetration-depth unlimited nuclide imaging and dynamic real-time optical imaging, respectively. However, commonly reported dual-modality imaging agents are composed of novel but safety-unproven materials, making their quick clinical translation challenging. Herein, we report a novel nanoparticle composed of facile hospital-available drugs and isotope for single-photon emission computed tomography (SPECT)/near-infrared (NIR) fluorescence imaging to detect SLNs.

METHODS

Indocyanine green-human serum albumin (ICG-HSA) nanoparticles (NPs) were synthesized by ICG-induced HSA self-assembly and further 99mTc-labeling via a one-step, facile hospital-available method. After injecting 99mTc-ICG-HSA into the rats' forepaw pads, the rats' draining axillary lymph nodes were visualized by preoperative mapping with SPECT/CT and intraoperative biopsy with NIR fluorescence. The axillary lymph nodes of rats were identified by pathology and fluorescent staining after execution. Additionally, its toxicity testing and comparison with 99mTc-sulfur colloid imaging were also explored.

RESULTS

The study reported a self-assembled 99mTc-ICG-HSA with a high radiochemical yield (85.6 ± 3.8%). Compared with conventional 99mTc-sulfur colloid, 99mTc-ICG-HSA NPs showed faster SLN identification, higher renal clearance, and lower hepatic retention. Furthermore, NIRF imaging allowed for the accurate visualization of the SLN and guided SLN biopsy intraoperatively. Notably, the 99mTc-ICG-HSA NPs were composed of hospital-available drugs and isotope, which are safe for acute toxicity evaluation by a certified institute.

CONCLUSION

The proposed 99mTc-ICG-HSA NPs are safe and capable of noninvasive SLN identification and biopsy guidance with multi-modal imaging strategies and could be a promising tool for clinically assisted SLN biopsy.

Staging of Cervical Cancer: A Practical Approach Using MRI and FDG PET

This review provides a practical approach to the imaging evaluation of patients with cervical cancer (CC), from initial diagnosis to restaging of recurrence, focusing on MRI and FDG PET. The primary updates to the International Federation of Gynecology and Obstetrics (FIGO) CC staging system, as well as these updates' relevance to clinical management, are discussed. The recent literature investigating the role of MRI and FDG PET in CC staging and image-guided brachytherapy is summarized. The utility of MRI and FDG PET in response assessment and posttreatment surveillance is described. Important findings on MRI and FDG PET that interpreting radiologists should recognize and report are illustrated. The essential elements of structured reports during various phases of CC management are outlined. Special considerations, including the role of imaging in patients desiring fertility-sparing management, differentiation of CC and endometrial cancer, and unusual CC histologies, are also described. Finally, future research directions including PET/MRI, novel PET tracers, and artificial intelligence applications are highlighted.

Intra- and peri-tumoral MRI radiomics features for preoperative lymph node metastasis prediction in early-stage cervical cancer

BACKGROUND

Noninvasive and accurate prediction of lymph node metastasis (LNM) is very important for patients with early-stage cervical cancer (ECC). Our study aimed to investigate the accuracy and sensitivity of radiomics models with features extracted from both intra- and peritumoral regions in magnetic resonance imaging (MRI) with T2 weighted imaging (T2WI) and diffusion weighted imaging (DWI) for predicting LNM.

METHODS

A total of 247 ECC patients with confirmed lymph node status were enrolled retrospectively and randomly divided into training (n = 172) and testing sets (n = 75). Radiomics features were extracted from both intra- and peritumoral regions with different expansion dimensions (3, 5, and 7 mm) in T2WI and DWI. Radiomics signature and combined radiomics models were constructed with selected features. A nomogram was also constructed by combining radiomics model with clinical factors for predicting LNM.

RESULTS

The area under curves (AUCs) of radiomics signature with features from tumors in T2WI and DWI were 0.841 vs. 0.791 and 0.820 vs. 0.771 in the training and testing sets, respectively. Combining radiomics features from tumors in the T2WI, DWI and peritumoral 3 mm expansion in T2WI achieved the best performance with an AUC of 0.868 and 0.846 in the training and testing sets, respectively. A nomogram combining age and maximum tumor diameter (MTD) with radiomics signature achieved a C-index of 0.884 in the prediction of LNM for ECC.

CONCLUSIONS

 Radiomics features extracted from both intra- and peritumoral regions in T2WI and DWI are feasible and promising for the preoperative prediction of LNM for patients with ECC.

Sentinel lymphatic mapping for gynecologic malignancies

PURPOSE OF REVIEW

To summarize the latest data in Gynecologic Oncology for the use of sentinel lymphatic mapping in vulvar, uterine, and cervical cancers.

RECENT FINDINGS

To decrease morbidity and improve detection of lymphatic metastasis, lymphatic mapping with sentinel lymph node biopsy is emerging as standard of care over conventional systemic lymphadenectomy in the surgical management of gynecologic malignancies.

SUMMARY

Sentinel lymph node mapping with biopsy is one of the most significant advances in cancer surgery. The presence of nodal metastasis is not only a prognostic factor for recurrence and survival in patients with gynecologic malignancies, but also guides assessment for adjuvant treatment. This review article discusses the most recent clinical updates in sentinel lymph node mapping, dissection, and management in vulvar cancer, endometrial cancer, and cervical cancer.

[Carbon nanoparticle tracing of sentinel lymph nodes in diagnosis and treatment of cervical cancer and clinical value of lymph node ultrastaging detection]

OBJECTIVE

To evaluate the clinical value of sentinel lymph node (SLN) detection using carbon nanoparticles in the diagnosis and treatment of cervical cancer and the value of lymph node pathological ultrastaging detection.

METHODS

A total of 79 patients with cervical cancer in IA2, IB1, IB2, IIA1 and IIICp1 stages admitted to the Department of Gynecology and Obstetrics, Nanfang Hospital between June, 2018 and January, 2021 were included in this study. During the operation, the patients were injected with a total of 0.25 mL carbon nanoparticles at 3 and 9 o'clock of the normal cervix after general anesthesia. The first black-dyed lymph nodes were identified as SLNs and removed one by one. All the patients underwent pelvic lymph node dissection and radical hysterectomy with or without para-aortic lymphadenectomy. The black-dyed SLNs were removed for routine pathological examination. Thirty patients with negative SLNs were randomly selected for pathological ultrastaging.

RESULTS

In 67 of the 79 patients, a total of 417 SLNs were detected with a detection rate of 84.8%; in each patient, at least 1 SLN was detected with a mean SLN number of 5.28. After the operation, 5 patients were found to have positive SLNs; 1 patient was negative for SLN but positive for non-SLN. The sensitivity of SLN biopsy was 83.3% with a specificity of 100%, false negative rate of 16.7%, an accuracy of 98.5% and a negative predictive value of 98.4%. SLN was distributed mainly in the obturator region, the external iliac region, the internal iliac region and the total iliac region (15.11%). Univariate and multivariate analyses suggested that preoperative cervical coning (P=0.045 and 0.009) and tumor size (P=0.033 and 0.008) significantly affected the overall detection rate of SLN. Kappa test showed a high consistency between SLN and pelvic lymph node metastasis status (Kappa value=0.901, P < 0.001). In 30 patients with negative pathological results of SLN, pathological ultrastaging detection identified no micrometastases or isolated tumor cells.

CONCLUSION

Carbon nanoparticle tracing of the SLNs is safe and feasible in the diagnosis and treatment of cervical cancer, and SLN detection is safe in patients with primary lesion size below 2 cm or without cervical conization. SLN combined with pathological ultrastaging detection does not improve the detection rate of isolated tumor cells or micrometastases.

Progress in surgical oncology: Gynecology perspective

Since its founding in 1884, Memorial Sloan Kettering Cancer Center (MSK) has set standards of care in gynecologic oncology. Over time, the MSK treatment approach evolved into an effort of gynecologic oncology experts across disciplines. As the anatomic field of gynecologic oncology surgery expanded beyond the pelvis, experts in other fields of cancer care, including our hepatobiliary and thoracic colleagues, joined this interprofessional effort. Here, we describe recent, key contributions to surgical gynecologic oncology by the Gynecology Service at MSK.

Estimation risk of lymph nodal invasion in patients with early-stage cervical cancer: Cervical cancer application

Introduction

Lymph node status is a major prognostic factor in early-stage cervical cancer. Predicting the risk of lymph node metastasis is essential for optimal therapeutic management. The aim of the study was to develop a web-based application to predict the risk of lymph node metastasis in patients with early-stage (IA1 with positive lymph vascular space invasion, IA2 and IB1) cervical cancer.

Materials and methods

We performed a secondary analysis of data from two prospective multicenter trials, Senticol 1 and 2 pooled together in the training dataset. The histological risk factors were included in a multivariate logistic regression model in order to determine the most suitable prediction model. An internal validation of the chosen prediction model was then carried out by a cross validation of the ‘leave one out cross validation’ type. The prediction model was implemented in an interactive online application of the ‘Shinyapp’ type. Finally, an external validation was performed with a retrospective cohort from L’Hôtel-Dieu de Québec in Canada.

Results

Three hundred twenty-one patients participating in Senticol 1 and 2 were included in our training analysis. Among these patients, 280 did not present lymph node invasion (87.2%), 13 presented isolated tumor cells (4%), 11 presented micrometastases (3.4%) and 17 macrometastases (5.3%). Tumor size, presence of lymph-vascular space invasion and stromal invasion were included in the prediction model. The Receiver Operating Characteristic (ROC) Curve from this model had an area under the curve (AUC) of 0.79 (95% CI [0.69– 0.90]). The AUC from the cross validation was 0.65. The external validation on the Canadian cohort confirmed a good discrimination of the model with an AUC of 0.83.

Discussion

This is the first study of a prediction score for lymph node involvement in early-stage cervical cancer that includes internal and external validation. The web application is a simple, practical, and modern method of using this prediction score to assist in clinical management.

Indocyanine green-guided sentinel lymph node mapping during laparoscopic surgery with vaginal cuff closure but no uterine manipulator for cervical cancer

BACKGROUND

Lymph node metastasis is a critical prognostic factor in cervical cancer. Considering the potential complications of lymphadenectomy and desirability of avoiding systemic lymphadenectomy, accurate intraoperative prediction of the existence of lymph node metastasis is important in patients undergoing surgery for cervical cancer. We evaluated the feasibility and value of indocyanine green (ICG) use for sentinel lymph node (SLN) mapping during laparoscopic surgery performed for cervical cancer.

METHODS

This single-center cohort study included 77 patients undergoing a new laparoscopic radical surgery method with pelvic lymphadenectomy for early-stage cervical cancer. The surgery, performed without using a uterine manipulator, included creation of a vaginal cuff. Bilateral ICG-guided SLN mapping and rapid histopathological examination were performed, and results were analyzed in relation to final histopathologic diagnoses.

RESULTS

The SLN pelvic side-specific detection rate was 93.5%, sensitivity (SLN-positive cases/SLN-detected pelvic lymph node-positive cases) was 100%, intraoperative negative predictive value (NPV) was 97.8%, and final pathological NPV was 100%. The detection rate was significantly lower for tumors ≥ 2 cm in diameter than for tumors < 2 cm in diameter. Micrometastases were missed by intraoperative examination in 3 cases.

CONCLUSION

The high NPV suggests the feasibility and usefulness of ICG-based SLN mapping plus rapid intraoperative examination for identification of metastatic SLNs. Use of ICG-based mapping for intraoperative identification of SLNs in patients undergoing this new laparoscopic surgery method for early-stage cervical cancer was particularly effective for tumors < 2 cm in diameter. However, incorporating a search for micrometastases into rapid intraoperative histopathologic examination may be necessary.

Clinical Study of Sentinel Lymph Node Detection to Evaluate Pelvic Lymph Node Metastasis to Determine the Prognosis of Patients with Early Cervical Cancer

Objective

Lymph node status is one of the most important prognostic factors for uterine cervical cancer. Sentinel lymph node (SLN) biopsy has emerged as a potential alternative to systematic lymphadenectomy for the lymph node mapping in such patients. However, the SLN metastasis detection via SLN biopsy in early-stage cervical cancer remains controversial. The current study is aimed at investigating the feasibility and accuracy of combined tracer method for localization of SLN in initial stages of cervical cancer and to evaluate the clinical value of SLN biopsy in replacing pelvic lymph node resection.

Methods

We retrospectively reviewed 348 cases who were admitted to the Department of Gynecologic Oncology, Shandong Provincial Cancer Hospital, China, between February 2003 and June 2018 with FIGO stage IA2 to IIA2 cervical cancer and undergone through SLN biopsy. Methylthioninium chloride was injected in combination with ^99mtechnetium-labeled sulfur colloid prior to surgery to these patients. SLNs were identified intraoperatively, excised, and subsequently submitted to fast frozen section. The detection rates, accuracy, sensitivity, coincidence rate, false negative rate, and negative predictive values of these cases were estimated, and the follow-up outcomes were carefully observed. Chi squared test or Fisher's exact test was employed for a comparison of the categorical variables. Univariate and multivariate Cox proportional hazard models were used for estimation of relationships between overall survival (OS) and disease-free survival (DFS) and prognostic factors.

Results

The total detection rate of SLN was 97.1% (338/348), and identification of bilateral SLN was successful in 237 patients (70.1%). The patient's tumor size, FIGO stage, lymph node metastasis, and depth of invasion had statistically significant differences in SLN detection rates. The detection rate had inverse relation with tumors size (>4 cm), invasive depth > 2/3, lymph node positive, late staging, and preoperative radiotherapy. 117 positive SLNs were detected in 73 patients. The negative predictive value, sensitivity, false negative rate, and coincidence rate and were 97.7%, 92.4%, 7.6%, and 95.4%, respectively. In patients whose tumor size were ≦ 4 cm, the false negative rate was 4.55% (2/44), whereas it was 0 in patients with tumor size≦2 cm. The respective 1, 3, and 5-year OS was 100%, 94.8%, and 91.8%, respectively, whereas DFS rate for 1, 3, and 5 years was 96.7%, 92%, and 89.6%, respectively. The lymph node was positive, tumor size, the depth of invasion, and staging were statistically different from the recurrence rate and survival rate of patients (p < 0.05). When tumor metastasis exceeded SLN, the recurrence rate was significantly increased, and survival rate is significantly reduced (p < 0.05, p < 0.01, p < 0.05, respectively).

Conclusions

The identification of SLN combined with ^99mtechnetium-labeled sulfur colloid and methylthioninium chloride has a good accuracy and is safe for the assessment of the status of pelvic nodes in patients with initial stage cervical cancer. Nuclide as a tracer has low dependence on objective conditions and doctors' technology and has a good detection rate. In our study, we believe that SLN biopsy is feasible when the tumor is ≦ 4 cm. Large scale clinical trials are required in China expand the sample size and validate the results of this study.

Sentinel lymph node detection by combining nonradioactive techniques with contrast agents: State of the art and prospects

The status of sentinel lymph nodes (SLNs) has a substantial prognostic value because these nodes are the first place where cancer cells accumulate along their spreading route. Routine SLN biopsy ("gold standard") involves peritumoral injections of radiopharmaceuticals, such as technetium-99m, which has obvious disadvantages. This review examines the methods used as "gold standard" analogs to diagnose SLNs. Nonradioactive preoperative and intraoperative methods of SLN detection are analyzed. Promising photonic tools for SLNs detection are reviewed, including NIR-I/NIR-II fluorescence imaging, photoswitching dyes for SLN detection, in vivo photoacoustic detection, imaging and biopsy of SLNs. Also are discussed methods of SLN detection by magnetic resonance imaging, ultrasonic imaging systems including as combined with photoacoustic imaging, and methods based on the magnetometer-aided detection of superparamagnetic nanoparticles. The advantages and disadvantages of nonradioactive SLN-detection methods are shown. The review concludes with prospects for the use of conservative diagnostic methods in combination with photonic tools.

Clinical impact of low-volume lymph node metastases in early-stage cervical cancer: A comprehensive meta-analysis

OBJECTIVE

In order to define the clinical significance of low-volume metastasis, a comprehensive meta-analysis of published data and individual data obtained from articles mentioning micrometastases (MIC) and isolated tumor cells (ITC) in cervical cancer was performed, with a follow up of at least 3 years.

METHODS

We performed a systematic literature review and meta-analysis, following Cochrane's review methods guide and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcome was the disease-free survival (DFS), and the secondary outcome was the overall survival (OS). The hazard ratio (HR) was taken as the measure of the association between the low-volume metastases (MIC+ITC and MIC alone) and DFS or OS; it quantified the hazard of an event in the MIC (+/- ITC) group compared to the hazard in node-negative (N0) patients. A random-effect meta-analysis model using the inverse variance method was selected for pooling. Forest plots were used to display the HRs and risk differences within individual trials and overall.

RESULTS

Eleven articles were finally retained for the meta-analysis. In the analysis of DFS in patients with low-volume metastasis (MIC + ITC), the HR was increased to 2.60 (1.55-4.34) in the case of low-volume metastasis vs. N0. The presence of MICs had a negative prognostic impact, with an HR of 4.10 (2.71-6.20) compared to N0. Moreover, this impact was worse than that of MIC pooled with ITCs. Concerning OS, the meta-analysis shows an HR of 5.65 (2.81-11.39) in the case of low-volume metastases vs. N0. The presence of MICs alone had a negative effect, with an HR of 6.94 (2.56-18.81).

CONCLUSIONS

In conclusion, the presence of MIC seems to be associated with a negative impact on both the DFS and OS and should be treated as MAC.

Can Conization Specimens Predict Sentinel Lymph Node Status in Early-Stage Cervical Cancer? A SENTICOL Group Study

Simple Summary

Lymph node involvement is one of the major prognosis factors for early-stage cervical cancer. Improvement in preoperative identification of node-positive patients may lead to a more accurate triage to primary chemoradiation for these patients instead of radical surgery followed by adjuvant radiotherapy, given the increased morbidity of combined treatment. Several studies have well established risk factors for node involvement, but they are based on final pathologic examination of radical hysterectomy specimens and are usually extrapolated for preoperative risk assessment. Among these risk factors, tumor size, lymphovascular space invasion (LVSI) and depth of stromal invasion might be assessed in conization specimens. Our findings suggest that patients with depth of stromal invasion lower than 10 mm and no LVSI in conization specimens had lower risk of micro- and macrometastatic SLN. In this subpopulation, full node dissection may be questionable in case of SLN unilateral detection.

Abstract

Background: The prognosis of patients with cervical cancer is significantly worsened in case of lymph node involvement. The goal of this study was to determine whether pathologic features in conization specimens can predict the sentinel lymph node (SLN) status in early-stage cervical cancer. Methods: An ancillary analysis of two prospective multicentric database on SLN biopsy for cervical cancer (SENTICOL I and II) was carried out. Patients with IA to IB2 2018 FIGO stage, who underwent preoperative conization before SLN biopsy were included. Results: Between January 2005 and July 2012, 161 patients from 25 French centers fulfilled the inclusion criteria. Macrometastases, micrometastases and Isolated tumor cells (ITCs) were found in 4 (2.5%), 6 (3.7%) and 5 (3.1%) patients respectively. Compared to negative SLN patients, patients with micrometastatic and macrometastatic SLN were more likely to have lymphovascular space invasion (LVSI) (60% vs. 29.5%, p = 0.04) and deep stromal invasion (DSI) ≥ 10 mm (50% vs. 17.8%, p = 0.04). Among the 93 patients with DSI < 10 mm and absence of LVSI on conization specimens, three patients (3.2%) had ITCs and only one (1.1%) had micrometastases. Conclusions: Patients with DSI < 10 mm and no LVSI in conization specimens had lower risk of micro- and macrometastatic SLN. In this subpopulation, full node dissection may be questionable in case of SLN unilateral detection.

Sentinel lymph node mapping in early-stage cervical cancer: Meta-analysis

BACKGROUND

The value of sentinel lymph node (SLN) mapping for early-stage cervical cancer remains controversial. Therefore, we collected data to investigate the feasibility and diagnostic accuracy of SLN in patients with early-stage (IA-IIA) cervical cancer.

METHODS

We searched Embase, PubMed, and the Cochrane Library databases issued before June 1, 2020. The sample size of the selected study was at least 10 patients with early-stage (IA-IIA) cervical cancer, the pooled detection rates and the separate detection rate (overall detection rate, bilateral detection rate) using blue dye with Tc, technetium 99 (Tc) and indocyanine green (ICG) technique of early-stage cervical cancer was reported. R-3.6.1 software was used to evaluate pooled detection rate and sensitivity.

RESULTS

Two thousand one hundred sixty-four patients included for analysis in 28 studies ranging from 12 to 405 patients. The combined overall detection rate of SLN mapping was 95% with a 72% pooled bilateral detection rate. The sensitivity of the combined overall detection rate of SLN mapping was 94.99% as well as a sensitivity of 72.43% bilateral detection rate. The overall detection rate of SLN was 96% for blue dye with Tc, 95% for Tc, 98% for ICG technique. The bilateral detection rate of SLN was 76% for blue dye with Tc, 63% for Tc, 85% for ICG technique. The sensitivity of the overall detection rate of SLN mapping was 97.76% as well as a sensitivity of 84.96% bilateral detection rate of ICG technique.

CONCLUSION

In early-stage cervical cancer, overall detection rate of SLN mapping is elevated while bilateral detection rate is lower. The overall detection rate (98%) as well as bilateral rate (85%) of ICG seems to be a better SLN mapping technique among the method of SLN mapping (using blue dye with Tc, Tc or ICG). We believe SLN mapping may be considered contemporary technique which could provide additional benefits over traditional pelvic lymphadenectomy. While promising results in SLN mapping has been found, larger patient samples, including randomized studies, are required at the same time.

Sentinel Lymph Node Biopsy Is Feasible in Cervical Cancer Laparoscopic Surgery: A Single-Center Retrospective Cohort Study

Methods

A total of 100 cervical cancer patients undergoing laparoscopic surgery with SLN biopsy were included. Indocyanine green, carbon nanoparticles (CNPs), and a combination of both were used during surgeries. Detection rates, sensitivity, negative predictive value (NPV) of SLN biopsy, and related factors were analyzed.

Results

The overall and bilateral SLN detection rates were 92% (92/100) and 74% (74/100), respectively. Combined tracers had higher bilateral SLN detection rates than CNPs alone (p=0.005). Menopause and lymph node metastasis were associated with lower overall and bilateral SLN detection rates (p < 0.05). SLN biopsy sensitivity and NPV for lymph node metastasis in patients with at least one detected SLN were 81.8% (9/11) and 97.3% (72/74), respectively. Among those with bilateral detected SLNs, higher sensitivity and NPV of 87.5% (7/8) and 98.3% (57/58) were observed, respectively. SLN algorithm can ensure that all patients with lymph node metastasis are detected by SLN biopsy.

Conclusion

SLN biopsy appears to be safe and effective for specific cervical cancer patients with high detection rates and NPV in laparoscopic surgery, especially for those with detected bilateral SLNs and undergoing the SLN algorithm. Selecting suitable patients for SLN mapping has prospects for clinical application.

Pathological factors associated with non-sentinel lymph node metastasis in early stage cervical cancer

OBJECTIVE

To analyze the predictive factors for non-sentinel lymph node (non-SLN) metastasis in early-stage cervical cancer.

METHODS

We analyzed a series of 113 patients who underwent sentinel lymph node (SLN) mapping for cervical cancer. The SLNs were examined by immunohistochemistry (IHC) when the hematoxylin-eosin stain was negative.

RESULTS

The overall bilateral detection rate was 81.5%, with a median of two SLNs resected. The study ultimately included 92 patients with SLNs that were mapped who had also undergone systematic pelvic lymph node dissection. Thirteen (14.1%) patients had positive SLNs, with a median of one positive SLN. Regarding the size of SLN metastasis, one (1.1%) had isolated tumor cells (ITC), seven (7.6%) had micrometastases, and five (5.4%) had macrometastases. Notably, 46.1% (6/13) had lymph node metastases detected only after IHC. Five (38.5%) cases had positive non-SLNs, with a median count of one positive lymph node. Parametrial invasion was the only risk factor for positive non-SLN (p = .045). Regarding the size of SLN metastasis, non-SLN involvement was present in the only case with ITC (1/1), 42.9% (3/7) of cases with micrometastases, and in 20% (1/5) with macrometastases.

CONCLUSIONS

Our data suggest that parametrial invasion correlates with the risk of non-SLN metastasis in cervical cancer.

Sentinel lymph node biopsy in early stage cervical cancer: A meta-analysis

Background

The aim of this study was to determine the specific side detection rate of the sentinel lymph node biopsy and the accuracy in predicting lymph node metastasis in early stage cervical cancer.

Methods

A systematic search of databases was performed from the inception of the databases to 27 June 2020. Studies of cervical cancer patients with FIGO stage FIGO ⅠA~ⅡB, evaluating the sentinel lymph node biopsy with blue dye, technetium 99, combined technique (blue dye with technetium 99) or indocyanine green with a reference standard of systematic pelvis lymph node dissection or clinical follow‐up were included. Stata12.0 and Meta‐Disc 1.4 were used for the meta‐analysis.

Results

Of 2825 articles found, 21 studies (2234 women) were eventually included. Out of 21 studies, 20 met the detection rate evaluation criteria and six were included for sensitivity meta‐analysis. Due to heterogeneity, it was inappropriate to pool all studies. The pooled specific side detection rates were 85% in tumors up to 2 cm, 67% in tumors over 2 cm, 75.2% for blue dye, 74.7% for technetium 99, 84% for combined technique, and 85.5% for indocyanine green. The sentinel lymph node biopsy had a pooled specific side sensitivity of 88%. Adverse effects of sentinel lymph node biopsy appear minimal for most patients and are mainly related to the injection of blue dye.

Conclusions

Sentinel lymph node biopsy using a tracer with a high detection rate and ultrastaging is highly accurate and reliable when limited to seriously selected patients, with satisfactory bilateral lymph node mapping and where enough cases for learning curve optimization exist. Indocyanine green sentinel lymph node mapping seems to be a superior sentinel lymph node mapping technique compared to other methods at present.

Standardization of lower extremity quantitative lymphedema measurements and associated patient-reported outcomes in gynecologic cancers

Practice changing standardization of lower extremity lymphedema quantitative measurements with integrated patient reported outcomes will likely refine and redefine the optimal risk-reduction strategies to diminish the devastating limb-related dysfunction and morbidity associated with treatment of gynecologic cancers. The National Cancer Institute (NCI), Division of Cancer Prevention brought together a diverse group of cancer treatment, therapy and patient reported outcomes experts to discuss the current state-of-the-science in lymphedema evaluation with the potential goal of incorporating new strategies for optimal evaluation of lymphedema in future developing gynecologic clinical trials.

The impact of low-volume metastasis on disease-free survival of women with early-stage cervical cancer

PURPOSE

We aimed to assess the impact of low-volume metastasis (micrometastasis and isolated tumor cells) on disease-free survival (DFS) of women with early-stage cervical cancer.

METHODS

Women with clinically suspected stage 1A-IB2 (FIGO 2018 classification) disease who underwent retroperitoneal nodal staging between October 2010 and April 2018, were retrospectively analyzed. The group of women who had undergone lymphadenectomy and standard node pathologic analysis (H&E group), were compared to the group undergoing sentinel node mapping (SLN) and ultrastaging with or without lymphadenectomy (ultrastaging group). At a median follow-up of 45 months, the DFS curves were analyzed.

RESULTS

Overall, 573 patients were revised (272 in the H&E group and 302 in the ultrastaging group). Eighty-five patients presented lymph node metastasis (32 in H&E, 53 in ultrastaging). Ultrastaging protocol increased the rate of low-volume metastasis by 5.6%. Twenty patients showed exclusive micrometastasis or ITC's. Seventy-three recurrences occurred (35 in H&E, 38 in ultrastaging). Only 1 out of 53 patients in the ultrastaging group (1.9%) presented with micrometastasis recurred. The 3-year disease-free survival was 89% for the H&E group, and 88% for the ultrastaging group, respectively (p = 0.175).

CONCLUSION

Ultrastaging analysis allowed increasing the detection of low volume metastasis in women with early-stage cervical cancer. However, the type of nodal staging did not have an impact on patients' 3-year disease-free survival.

Laparoscopic sentinel lymph node dissection followed by open radical hysterectomy for early stage cervical cancer: A pilot study

OBJECTIVE

To propose a treatment algorithm, after the LACC trial, of laparoscopic sentinel lymph node biopsy with frozen section, followed by immediate open radical hysterectomy in node-negative cases, for early stage cervical cancer.

METHODS

We retrospectively collected all cases of cervical cancer that were surgically treated between 2019-2020. In all cases, surgery began with laparoscopic sentinel lymph node biopsy ± ovarian transposition. Node-negative cases continued with open radical hysterectomy. In node-positive cases, surgery was discontinued, sparing the patient a laparotomy incision.

RESULTS

Nine patients with cervical cancer were referred for surgery. Laparoscopic bilateral lymph node identification was achieved in all. In two cases, sentinel lymph nodes were positive for metastatic cancer and surgery was discontinued. For the other seven, node-negative patients, open radical hysterectomy was completed. Four patients had laparoscopic ovarian transposition. There were no cases where nodes were negative on frozen section but positive on final pathology.

CONCLUSION

Laparoscopic sentinel lymph node biopsy before open radical hysterectomy may spare a considerable number of laparotomies on the one hand and bi-modal treatment with surgery and radiation on the other, for node-positive patients. The oncological safety of this approach is yet to be determined.

Sentinel lymph node in cervical cancer: a literature review on the use of conservative surgery techniques

INTRODUCTION

Sentinel lymph node detection is a surgical procedure that allow to avoid systematic lymphadenectomy in those tumors in early stage where lymph node spread is not sure. If the sentinel lymph node is not involved by tumor in 98-99% of case other lymph nodes are clean. The reason why less radical surgery is chosen is linked to the lower postoperative morbidity rate, the risk of lower limb lymphedema decreases. The aim of this review was to summarize what is the state of art of using the sentinel lymph node dissection (SLD) technique and what are the future goals to improve the safety and the reliability.

EVIDENCE ACQUISITION

We have conducted a review of the literature of the past 10 years to understand the attitudes of oncologist gynecologists in the world to the conservative treatment of cervical cancer. We only selected articles from 2010 onwards, which meet the inclusion criteria.

EVIDENCE SYNTHESIS

The detection rate varies from 83% to 100%. The bilateral detection rate, on the other hand, varies from 42% to 100%. The false negative rate ranges from 4% to 12%. Sensitivity varies from 20.7% (considering the frozen section) to 100%.

CONCLUSIONS

Indocyanine green is the most reliable and performing tracer for the search of the sentinel lymph node; that the false intraoperative negative rate is too high to be sure not to subject the patient to an incorrect therapeutic procedure; data concerning the safety and survival of conservative lymphadenectomy (SLND) compared to systematic lymphadenectomy are still lacking in the literature and therefore we are awaiting the results of the two ongoing randomized clinical trials that will allow us to have more significant scientific data.

Sentinel lymph node intraoperative analysis in endometrial cancer

PURPOSE

Surgical staging in endometrial cancer has evolved and sentinel lymph node (SLN) mapping has replaced a full pelvic and paraaortic lymphadenectomy in several cases. An intraoperative evaluation of SLN might identify patients who could benefit the most from a full lymphadenectomy. The aim of this study is to evaluate the clinical relevance of frozen section of SLN.

METHODS

A retrospective analysis in patients with endometrial cancer who underwent SLN mapping with intraoperative evaluation at frozen section between February 2016 and September 2019 was performed. In case of metastatic involvement, a full lymphadenectomy was performed.

RESULTS

Fifty-eight patients met the inclusion criteria. Clinical-pathologic characteristics of the patients and surgical data were analyzed. Overall, bilateral and unilateral detection rates were 100% (58/58), 89.7% (52/58), and 10.3% (6/58), respectively. Eight patients had a stage IIIC disease at permanent section. Frozen section detected SLN metastases in four of eight patients. Of these, two were micrometastases and two were macrometastases. At frozen section of the SLNs, no macrometastases were misdiagnosed. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of frozen section in detecting metastases was 50%, 100%, 93%, 100% and 92.6%, respectively.

CONCLUSION

The intraoperative evaluation of SLN in endometrial cancer accurately identifies patients with macrometastases. This is the cohort that might benefit the most of a full lymphadenectomy for a higher risk of additional lymph node metastases.

Diagnostic value of sentinel lymph node scintigraphy and 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in the detection of metastatic lymph nodes in patients with early-stage cervical cancer

Cervical cancer is staged clinically using the International Federation of Gynaecology and Obstetrics staging system. Although lymph node status does not form part of the staging, it has important prognostic and potential therapeutic implications. The aim of the study was to evaluate the role of sentinel lymph node (SLN) scintigraphy and 2-[¹⁸F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in detecting lymph node metastases in patients with early-stage cervical cancer. Thirty-six patients with early-stage cervical cancer underwent SLN detection during primary operation. Of the 36 patients, 28 patients underwent ¹⁸F-FDG PET/CT before surgery. The ¹⁸F-FDG PET/CT images were analyzed with the histopathological findings as the reference standard. The diagnostic performance of ¹⁸F-FDG PET/CT in the detection of nodal disease was reported in terms of accuracy value. The SLN detection rate was the highest (91.7%) using the combined method (lymphoscintigraphy, intraoperative gamma probe, and blue dye). Seven of the thirty-six patients had lymph node involvement (19.4%), of which five had preoperative ¹⁸F-FDG PET/CT imaging. On overall patient-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of ¹⁸F-FDG PET/CT were 40.0%, 78.3%, 28.6%, 85.7%, and 71.4%, respectively. The combination of radiolabeled nanocolloid with blue dye is safe and reliable and allows successful detection of SLNs in patients with early-stage cervical cancer in a population with high prevalence of human immunodeficiency virus. The specificity and NPV of ¹⁸F-FDG PET/CT are high and can be used in conjunction with SLN biopsy.

Superparamagnetic iron oxide as a tracer for sentinel lymph node detection in uterine cancer: a pilot study

Sentinel lymph node (SLN) mapping using dye or radioisotopes has been performed in patients with uterine cancer. Superparamagnetic iron oxide (SPIO) can be handled safely and is taken up by lymph nodes (LNs); however, its efficacy in detecting SLNs in uterine cancer remains unknown. This pilot study evaluated the use of SPIO as a tracer for SLN detection in patients with uterine cancer. SPIO was injected into the uterine cervixes of 15 patients with uterine cancer scheduled for pelvic LN dissection. Magnetic resonance imaging (MRI) was performed preoperatively. Five patients also underwent radioisotope injection and single-photon emission computed tomography/computed tomography. Dissected LNs were stained with iron and examined pathologically. Of the radioisotope-positive LNs, 92% were also SPIO/MRI-positive. SPIO/MRI and iron staining were positively correlated. SLNs were identified by iron staining in 93% of cases. Iron staining was strongly positive in two of the five areas of LN metastasis; these were considered SLNs. Staining was negative or very weak in the other three areas and lymph flow disturbance was considered. SPIO and radioisotopes are taken up similarly by SLNs. SPIO/MRI and iron staining may thus be useful for detection of SLNs and diagnosis of LN metastasis in patients with uterine cancer.

Value of indocyanine green pelvic lymph node mapping in the surgical approach of cervical cancer

PURPOSE

Lymph node metastasis is a significant predictive factor for disease recurrence and survival in cervical cancer patients and relevant for therapeutic strategies. We evaluated the clinical value of indocyanine green (ICG) by measuring the sensitivity and negative predictive value of sentinel lymph node mapping compared with the gold standard of complete lymphadenectomy in detecting lymph node metastases for cervical cancer.

METHODS

We utilized the near-infrared imaging agent ICG to detect tumor-infested lymph nodes in the pelvis analogue to a classical sentinel lymph node procedure by analyzing data from 20 patients who had undergone surgery for cervical cancer at our institution. A laparoscopic lymph node mapping procedure by means of ICG, followed by a complete pelvic lymphadenectomy with or without paraaortic lymphadenectomy was done in all patients.

RESULTS

Histological examination identified seven patients with tumor-positive pelvic nodes, whereas mapping with ICG identified only five of these patients. Detection rate of positive nodes by ICG mapping and false negative rate was 71.4% and 28.6%, respectively; bilateral detection rate was 83.3%. One of the two false negative patients additionally suffered from deep infiltrating endometriosis.

CONCLUSIONS

Our results indicate that ICG can identify the relevant pelvic nodes independent of tumor size, provided bilateral detection is achieved and additional, related diseases are excluded.

TRIAL REGISTRATION

This trial is registered within the German Clinical Trial Register (DRKS-ID: DRKS00014692).

Positron Lymphography via Intracervical 18F-FDG Injection for Presurgical Lymphatic Mapping in Cervical and Endometrial Malignancies

The presence of metastasis in local lymph nodes (LNs) is a key factor influencing choice of therapy and prognosis in cervical and endometrial cancers; therefore, the exploration of sentinel LNs (SLNs) is highly important. Currently, however, SLN mapping requires LN biopsy for pathologic evaluation, since there are no clinical imaging approaches that can identify tumor-positive LNs in early stages. Staging lymphadenectomy poses risks, such as leg lymphedema or lymphocyst formation. Furthermore, in 80%-90% of patients, the explored LNs are ultimately tumor-free, meaning most patients are unnecessarily subjected to lymphadenectomy. Methods: Current lymphoscintigraphy methods identify only the anatomic location of the SLNs and do not provide information on their tumor status. There are no noninvasive methods to reliably identify metastases in LNs before surgery. We have developed positron lymphography (PLG), a method to detect tumor-positive LNs, in which ¹⁸F-FDG is injected interstitially into the uterine cervix on the day of surgery, and its rapid transport through the lymphatic vessels to the SLN is then visualized with dynamic PET/CT. We previously showed that PLG was able to identify metastatic LNs in animal models. Here, we present the first results from our pilot clinical trial (clinical trials identifier NCT02285192) in 23 patients with uterine or cervical cancer. On the morning of surgery, ¹⁸F-FDG was injected into the cervix, followed by an immediate dynamic PET/CT scan of the pelvis and a delayed 1-h whole-body scan. Results: There were 3 (15%) node-positive cases on final pathologic analysis, and all of these LNs (including 1 with a focus of only 80 tumor cells) were identified by PLG. There were 2 (10%) false-positive cases with PLG, in which the final pathology of the corresponding SLNs was negative for tumor. Conclusion: This first-in-humans study of PLG in women with uterine and cervical cancer demonstrates its feasibility and its ability to identify patients with nodal metastases and warrants further evaluation in additional studies.

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.

Risk factors for failure of bilateral sentinel lymph node mapping in early-stage cervical cancer

BACKGROUND

The objective of this study was to determine clinical, tumoral and surgical factors associated with successful bilateral sentinel lymph node mapping (SBM) in early-stage cervical cancer.

METHODS

We performed an ancillary work on the data of two prospective trials on SLN biopsy for FIGO IA-IIA cervical cancer (SENTICOL I & II). Patients having Sentinel lymph node (SLN) mapping for early-stage cervical cancer were included between 2005 and 2012 from 28 French oncologic centers. SLN was detected by a combined labeling technique (blue and isotopic).

RESULTS

405 patients were included for analysis: SLNs were identified on at least one side of the pelvis in 381 patients (94.1%) and bilaterally in 326 patients (80.5%). The mean age was 45.4 years [22-85 years]. Most patients had IB1 pathologic FIGO 2018 stage (81.3%) and squamous cell carcinoma (71%). Surgeries were mainly performed by minimally invasive approach (368 patients - 90.9%). By multivariate analysis, lower SBM rate was significantly associated with Age ≥70 years (ORa = 0.02, 95%CI = [0.001-0.28], p = 0.004), tumor size larger than 20 mm (ORa = 0.46,95%CI = [0.21-0.99], p = 0.048) and Body-mass index higher than 30 kg/m² (ORa = 0.28, 95%CI = [0.12-0.65], p = 0.003). SBM rate was significantly higher in high skills centers (>5patients/year) (ORa = 8.05, 95%CI = [2.06-31.50], p = 0.003) and in SENTICOL II (2009-2012) compared to SENTICOL I (2005-2007) (ORa = 2.6, 95%CI = [1.23-5.51], p = 0.01).

CONCLUSIONS

In early-stage cervical cancer, bilateral SLN detection rates is lower in patients aged more than 70years, patients with BMI≥30 kg/m² and larger tumor ≥20 mm whereas stronger experience of SLN biopsy technique improves bilateral SLN detection.

[Sentinel lymph node biopsy in early-stage cervical cancer: current state of art]

Lymph node status is the most important prognostic factor of survival in women with early stage cervical cancer. Sentinel lymph node (SLN) biopsy is an accurate method for the assessment of lymph nodal involvement in early-stages cervical cancer and has been increasingly used instead of systematic pelvic lymph node dissection (PLND). Less-radical lymph node dissection decreases the associated morbidity of PLND, especially the risk of lower-leg lymphoedema, which affects severely patient quality of life. SLN biopsy allows nodes ultrastaging and provides supplementary histological information by increasing the detection of tumor low-volume (isolated tumors cells and micrometastases). Moreover, SLN biopsy provides accurate anatomical information on pelvic lymphatic drainage pathway by identifying nodes outside of routine lymphadenectomy areas. Selection of a population at low-risk of nodal metastasis, a minimal training, and simple rules may ensure a low false negative rate. Several studies have shown that SLN mapping in these patients is feasible, with excellent detection rates and sensitivity. Combined detection with technetium-99 and blue dye has been widely used but recently, there has been increasing interest in the use of fluorescent dies such as indocyanine green (ICG) which would improve SLN detection. Although recent international guidelines recommend performing SLN biopsy in addition to PLND, SLN biopsy alone is not the gold-standard yet due to lack of prospective evidence, especially on long-term oncological safety. Some points remain controversial such as the low accuracy of intraoperative SLN status assessment by frozen section and the impact of micrometastasis on prognostic. The prospective randomized clinical trial SENTICOL III will answer to these problematics.