Which is better for predicting pelvic lymph node metastases in patients with cervical cancer: Fluorodeoxyglucose-positron emission tomography/computed tomography or a sentinel node biopsy? A retrospective observational study

Sentinel Lymph Node Staging in Early-Stage Cervical Cancer: A Comprehensive Review

Cervical cancer (CC) continues to be a significant global public health concern, even with preventive measures in place. In women with early-stage CC, the status of lymph nodes is of paramount importance, not only for the final prognosis but also for determining the best therapeutic strategy. According to main international guidelines, pelvic full lymphadenectomy (PLND) is recommended for lymph node staging. However, in these early stages of CC, sentinel lymph node biopsy (SLNB) has emerged as a precise technique for evaluating lymph node involvement, improving its morbidity profile. We performed a literature review through PubMed articles about progress on the application of SLNB in women with early-stage CC focusing on the comparison with PET/CT and PLND in terms of oncological outcomes and diagnostic accuracy. While the superiority of SLNB is clear compared to radiologic modalities, it demonstrates no clear oncologic inferiority over PLND, given the higher detection rate of positive lymph nodes and predominance of no lymph node recurrences. However, due to a lack of prospective evidence, particularly concerning long-term oncological safety, SLNB is not the current gold standard. With careful patient selection and adherence to straightforward protocols, a low false-negative rate can be ensured. The aim of the ongoing prospective trials is to address these issues.

Risk Factor Assessment of Lymph Node Metastasis in Patients With FIGO Stage IB1 Cervical Cancer

Objectives

To assess the risk factors of lymph node metastasis (LNM) in patients with FIGO stage (2009) IB1 cervical cancer (CC).

Methods

Patients with FIGO stage IB1 CC who underwent radical resection between 2012 and 2018 were recruited. The risk factors for LNM were analysed. A recursive partitioning analysis (RPA) was used to divide the patients into risk groups and assess their risk of LNM.

Results

The 5-year overall survival rate was 91.72%, while 80.0% and 93.5% for patients with or without LNM (P<0.05). Multivariable logistic regression analysis showed that lymphovascular invasion (LVI), depth of invasion (DI), tumour size (TS), squamous cell carcinoma (SCC) antigen level were independent risk factors (all P<0.05). Patients were divided into low-risk (no LVI, DI <1/2, TS <2 cm), intermediate-risk (no LVI, DI <1/2, TS ≥2 cm; no LVI, DI ≥1/2, normal SCC level; LVI, DI <1/2, TS <2 cm), and high-risk (no LVI, DI ≥1/2, SCC level ≥1.5 ng/ml; LVI, TS <2 cm, DI ≥1/2; LVI, TS ≥2 cm) groups by RPA according to these four factors. The incidence of LNM among the three groups was 0.00%, 4.40%, and 24.10%, respectively (all P<0.001). The 5-year overall survival rates differed among the groups (98.2%, 92.7%, 83.0%, respectively, P=0.001).

Conclusions

LNM affects the prognosis of patients with FIGO stage IB1 CC. Lymphadenectomy may be avoided for patients in the low-risk group and recommended for those in the high-risk group. Whether dissection is performed in the intermediate-risk group depends on the lymph node biopsy results.

Comparison of Prognosis between Minimally Invasive and Abdominal Radical Hysterectomy for Patients with Early-Stage Cervical Cancer

Minimally invasive surgery (MIS) is performed to treat cervical cancer patients; however, a recent study showed that MIS was associated with higher recurrence and death rate compared with abdominal radical hysterectomy (ARH). In the current study, the prognosis of patients with early-stage cervical cancer who underwent MIS with vaginal closure or ARH was evaluated. One hundred and eighty-two patients underwent radical hysterectomy for cervical cancer with stage of IA2, IB1, and IIA1. MIS was performed by laparoscopy or a robot using the vaginal closure method. Disease-free survival (DFS) and overall survival (OS) were evaluated between the groups. Among the patients, 67 underwent MIS and 115 underwent ARH. The recurrence rate was 4.5% in MIS patients and 3.5% in ARH patients with a median follow-up (interquartile range) of 36 (18–60) and 78 (48–102) months, respectively. DFS and OS were not different between the groups (3y-DFS, 95.3% vs. 96.1%, p = 0.6; 3y-OS, 100% vs. 100%, p = 0.06). In early-stage cervical cancer patients, MIS with vaginal closure did not increase the risk for recurrence or death. Surgical techniques and procedures to avoid spillage of tumor cells could be important for a better prognosis.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

Role of carbon nanoparticle suspension in sentinel lymph node biopsy for early-stage cervical cancer: a prospective study

OBJECTIVE

To evaluate the clinical diagnostic validity of carbon nanoparticle suspension (CNS) in sentinel lymph node biopsy (SLNB) for assessing lymphatic spread of early-stage cervical cancer.

DESIGN

A prospective study.

SETTING AND POPULATION

356 cases.

METHODS

We enrolled 356 stage Ia2-IIa2 cervical cancer patients to undergo SLNB using CNS, followed by systematic pelvic lymphadenectomy. All lymph node specimens were assessed using conventional histopathologic ± pathologic ultrastaging analyses.

MAIN OUTCOME MEASURES

Sentinel lymph node detection rate (DR), clinical diagnostic validity and various related factors were analysed.

RESULTS

CNS identified 1456 SLNs in 325 patients. The overall SLN DR was 91.29%. A significantly higher DR was found for patients with tumours <20 mm (97.75% versus 71.91%; P < 0.001). Two patients had false-negative results. SLNB with CNS had sensitivity of 96.65%, false-negative rate (FNR) of 4.35% and negative predictive value (NPV) of 99.29%. Importantly, sensitivity (100%), NPV (100%) and FNR (0%) were improved when testing the subgroup of patients with tumours <20 mm (267 cases). There were no observed differences in DR based on pathological type or grade, stage, depth of stromal invasion, surgical approach, menopausal status or prior treatment with chemotherapy (P > 0.05).

CONCLUSIONS

Sentinel lymph node biopsy with CNS results in favourable DR, sensitivity and NPV for women with early-stage cervical cancer with small tumour sizes. SLNB with CNS is safe, feasible and relatively effective for guiding precise surgical treatment of early-stage cervical cancer.

TWEETABLE ABSTRACT

Sentinel lymph node biopsy with carbon nanoparticle suspension is safe and feasible for early-stage cervical cancer.

The feasibility of 18F-FDG PET/CT for predicting pathologic risk status in early-stage uterine cervical squamous cancer

Background

Postoperative pathologic risk factors (PRFs) could increase the recurrence rate in early-stage uterine cervical squamous cancer (ECSC). Our study intended to explore the efficiency of ¹⁸F-FDG PET/CT for assessing the pathologic risk status (PRS) in ECSC patients.

Methods

This retrospective study was performed in 240 ECSC patients with stage IA2-IIA2 (FIGO 2009), who underwent preoperative PET/CT scans and subsequent radical surgery between January 2010 and July 2015. Intermediate-risk (tumour diameter ≥ 4 cm, stromal invasion depth ≥ 1/2, lymphovascular space invasion (LVSI)), and high-risk factors (parametria involvement, positive surgery margin, pelvic lymph node metastasis) were confirmed by postoperative pathology. Patients with none of these PRFs were at a low risk for relapse. One of these PRFs was defined as positive risk. The relationship between each PRF and ¹⁸F-FDG uptake was analysed by t-test. Chi-square tests and logistic regression analyses were used to determine the efficiency of PET/CT parameters for assessing the PRS. The area under the curve (AUC) was used as an indicator for predictive efficiency.

Results

Patients with higher SUVmax (p < 0.001), MTV (p < 0.001) and TLG (p < 0.001) had larger tumour sizes and deeper stromal invasion. Further multivariate analyses showed SUVmax and TLG were independent predictors for positive- and intermediate-risk status. In high-risk group, MTV and TLG were associated with pelvic lymph node metastasis and parametria involvement. However, only MTV was a significant indicator.

Conclusions

Preoperative ¹⁸F-FDG PET/CT had an independent predictive value for PRS in ECSC.

The Diagnostic Accuracy of an Intraoperative Frozen Section Analysis and Imprint Cytology of Sentinel Node Biopsy Specimens from Patients with Uterine Cervical and Endometrial Cancer: a Retrospective Observational Study

Sentinel node biopsy (SNB) may be a decision-making tool for function preservation surgery, including radical trachelectomy and ovary preservation in the treatment of cervical and endometrial cancer. The intraoperative diagnosis is important for guiding treatment decisions for patients with these conditions. Three hundred seventy-one patients with cervical and endometrial cancer received SNB with an intraoperative frozen section analysis and imprint cytology. The sentinel node was cut in half, parallel to the longest axis, to obtain the maximum section area. After performing imprint cytology, one half was used to create a frozen section. The specimen was cut at 2-mm intervals into 5-μm-thick sections, which were subjected to hematoxylin and eosin staining. The diagnostic accuracy of intraoperative frozen section analyses and imprint cytology was compared to the final pathological diagnosis. Among 951 detected sentinel nodes, 51 nodes were found to be positive in the final pathological diagnosis. The sensitivity of a frozen section analysis, imprint cytology and the combination of the two modalities was 76.5%, 72.6%, and 92.2%, respectively. The specificity of a frozen section analysis and imprint cytology was 100%. The negative predictive value of a frozen section analysis and imprint cytology was 98.7% and 98.5%, respectively. In these settings, the accuracy of the frozen section analysis and imprint cytology in the evaluation of SNB specimens was considered acceptable; however, the sensitivity of the combined approach was higher in comparison to when a frozen section analysis or imprint cytology was performed alone.

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.