Effectiveness of sentinel lymph node biopsy and bilateral pelvic nodal dissection using methylene blue dye in early-stage operable cervical cancer-A prospective study

OBJECTIVE

To evaluate the effectiveness of methylene blue dye in detecting sentinel lymph nodes (SLNs) in women with early-stage operable (defined as FIGO I-IIA) cervical cancer. It also aims to evaluate procedural challenges and accuracy.

METHOD

This prospective study, which focused on 20 women with early-stage cervical cancer, was carried out between June 2016 and December 2017. These patients had SLN mapping with methylene blue dye injections and thorough examinations, including imaging. All patients underwent radical hysterectomy and complete bilateral pelvic lymphadenectomy. No additional investigation was done on the lymph node in cases where a metastasis was found in the first H&E-stained segment of the sentinel node.

RESULT

20 patients were included in the analysis. The median age of the subjects was 53, and 95 % of them had squamous cell carcinoma. 90 % of the time, the identification of SLNs was effective, and 55 SLNs were found, of which 52.7 % were on the right side of the pelvis and 47.3 % on the left. The obturator group had the most nodes, followed by the external and internal iliac groups in descending order of occurrence. Metastasis was detected in 3 patients, resulting in a sensitivity of 100 % and a specificity of 93.75 % for SLN biopsy. Notably, no false-negative SLNs were found. Complications related to methylene blue usage included urine discoloration in 30 % of patients.

CONCLUSION

This trial highlights the promising efficacy and safety of methylene blue dye alone for SLN identification in early-stage operable cervical cancer, with a notably higher success rate. Despite limitations like a small sample size, healthcare professionals and researchers can build upon the insights from this study to enhance cervical cancer management.

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.

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.

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.

Sentinel Lymph Nodes Mapping in Cervical Cancer a Comprehensive Review

Objective

A comprehensive literature search for more recent studies pertaining to sentinel lymph node mapping in the surveillance of cervical cancer to assess if sentinel lymph node mapping has sensitivity and specificity for evaluation of the disease; assessment of posttreatment response and disease recurrence in cervical cancer.

Materials and Methods

The literature review has been constructed on a step wise study design that includes 5 major steps. This includes search for relevant publications in various available databases, application of inclusion and exclusion criteria for the selection of relevant publications, assessment of quality of the studies included, extraction of the relevant data and coherent synthesis of the data.

Results

The search yielded numerous studies pertaining to sentinel lymph node mapping, especially on the recent trends, comparison between various modalities and evaluation of the technique. Evaluation studies have appraised high sensitivity, high negative predictive values and low false-negative rate for metastasis detection using sentinel lymph node mapping. Comparative studies have established that of all the modalities for sentinel lymph node mapping, indocyanine green sentinel lymph node mapping has higher overall and bilateral detection rates. Corroboration of the deductions of these studies further establishes that the sentinel node detection rate and sensitivity are strongly correlated to the method or technique of mapping and the history of preoperative neoadjuvant chemotherapy.

Conclusions

The review takes us to the strong conclusion that sentinel lymph node mapping is an ideal technique for detection of sentinel lymph nodes in cervical cancer patients with excellent detection rates and high sensitivity. The review also takes us to the supposition that a routine clinical evaluation of sentinel lymph nodes is feasible and a real-time florescence mapping with indocyanine green dye gives better statistically significant overall and bilateral detection than methylene blue.

Can We Define the Risk of Lymph Node Metastasis in Early-Stage Cervical Cancer Patients? A Large-Scale, Retrospective Study

BACKGROUND

Sentinel lymph node (SLN) biopsy has emerged as one of the most appreciated techniques for reducing the rate of complete lymph node dissection (LND) performed in patients with early-stage cervical cancer (ECC). However, its performances are still a matter of debate and, to improve them, international guidelines recommend performing at least unilateral LND in case of SLN mapping. In a prior study, we identified a group of patients without evidence of lymph node metastasis (LNM). Our objective is to define a precise risk of LNM for each ECC patient in order to significantly tailor surgery for ECC.

METHODS

Clinical and pathological data of ECC patients were retrospectively collected by eight Italian institutions. Chi-square test or Fisher's exact test along with logistic regression analysis was used to determine the association of each variable between patients with or without LNM. Results of logistic regression have been used as a basis to calculate the probability to harboring LNM.

RESULTS

A total of 463 ECC patients were identified. No LNM was detected among the 161 (34.8%) patients who met the criteria and were defined as Very Low Risk. In the other 302 patients, the precise risk of LNM was calculated, and it was <1% in 31 (10.3%) patients.

CONCLUSIONS

Defining the precise risk of LNM could lead to proper selection of patients in whom any lymph nodal procedure, including SLN, could be avoided.

Beyond sentinel node algorithm. Toward a more tailored surgery for cervical cancer patients

Nowadays cervical cancer is frequently diagnosed at early stage. For these patients lymph node metastasis (LNM) is considered the most important prognostic factor. During the last decade many efforts have been made to reduce rate of complications associated with lymphadenectomy (LND). A great interest has arisen in sentinel lymph node (SLN) biopsy as a technique able to decrease number of LND performed and, at the same time, to assess lymph nodal status. High diagnostic performances have been reached thanks to SLN surgical algorithm. However, despite the efforts, about 25% of these patients undergo at least unilateral LND to meet NCCN recommendations. Data of women with International Federation of Gynecology and Obstetrics stage IA1‐IB1/IIA1 cervical carcinoma were retrospectively collected by six Italian institutions. All patients underwent complete preoperative staging workup and were primarily treated by radical hysterectomy and pelvic bilateral LND. A total of 368 patients with early‐stage cervical cancer were identified. Among them 333 (90.5%) showed no suspicious enlarged nodes at the preoperative magnetic resonance imaging (MRI). In this subset, tumor diameter ≥20 mm was the only independent predictor of LN status (P = 0.003). None of the 106 patients with negative MRI nodal assessment, with squamous and adenosquamous histotype and a tumor diameter less than 2 cm had LNM. Based on these results we propose a new modified SLN surgical algorithm that could safely reduce LND performed in patients with very low‐risk early‐stage cervical cancer.