Histopathologic Validation of the Sentinel Node Technique for Early-Stage Cervical Cancer Patients

Predictors of Non-Sentinel Lymph Node Metastasis in Patients with Positive Sentinel Lymph Node in Early-Stage Cervical Cancer: A SENTICOL GROUP Study

BACKGROUND

The goal of this study was to identify the risk factors for metastasis in the remaining non-sentinel lymph nodes (SLN) in the case of positive SLN in early-stage cervical cancer.

METHODS

An ancillary analysis of two prospective multicentric databases on SLN biopsy for cervical cancer (SENTICOL I and II) was performed. Patients with early-stage cervical cancer (FIGO 2018 IA to IIA1), with bilateral SLN detection and at least one positive SLN after ultrastaging, were included.

RESULTS

405 patients were included in SENTICOL I and Il. Fifty-two patients had bilateral SLN detection and were found to have SLN metastasis. After pelvic lymphadenectomy, metastatic involvement of non-SLN was diagnosed in 7 patients (13.5%). Patients with metastatic non-SLN were older (51.9 vs. 40.8 years, p = 0.01), had more often lympho-vascular space invasion (LVSI) (85.7% vs. 35.6%, p = 0.03), and had more often parametrial involvement (42.9% vs. 6.7%, p = 0.003). Multivariate analysis retained age (OR = 1.16, 95% IC = [1.01-1.32], p = 0.03) and LVSI (OR = 25.97, 95% IC = [1.16-582.1], p = 0.04) as independently associated with non-SLN involvement.

CONCLUSIONS

Age and LVSI seemed to be predictive of non-SLN metastasis in patients with SLN metastasis in early-stage cervical cancer. Larger cohorts are needed to confirm the results and clinical usefulness of such findings.

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 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.

Sentinel Lymph-Node Biopsy in Early-Stage Cervical Cancer: The 4-Year Follow-Up Results of the Senticol 2 Trial

INTRODUCTION

Senticol 2 is a randomized multicenter trial in the treatment of early-stage cervical cancer patients. The aim of the Senticol 2 study was to compare the effect of sentinel-lymph-node biopsy (SLNB) to that of SLNB + pelvic lymphadenectomy (PLND), and to determine the postoperative lymphatic morbidity in the two groups. Here, we report a secondary objective of this study: the follow up.

MATERIAL AND METHODS

In the Senticol 2 trial, patients underwent a laparoscopy with a sentinel-node-detection procedure and were randomized into two groups, namely: Group A, in which participants received SLNB, and Group B, in which participants received SLNB + PLND. Patients with an intra-operative macroscopically suspicious lymph node, were given a frozen-section evaluation and were randomized only if the results were negative. All of the patients received follow up with a clinical examination at 1, 3, and 6 months after surgery, and then every 3-4 months after that. The median follow up was 51 months (4 years and 3 months).

RESULTS

Disease-free survival after 4 years for the SLNB group and the SLNB + PLND group were 89.51% and 93.1% (p = 0.53), respectively. The only statistical factor associated with recurrence in the univariate analysis was the adjuvant radiotherapy. No other factors, including the age of the patients, histological type, tumor size, lymph vascular space invasion (LVSI), and positive nodal status, were significant in the univariate or multivariate analyses. The overall survival rates after 4 years in the SLNB and SLNB + PLND groups were 95.2% and 96% (p = 0.97), with five and four deaths, respectively. The univariate and multivariate analyses did not find any prognostic factors.

CONCLUSIONS

This randomized study confirmed the results of the Senticol 1 study and supports the sentinel lymph node (SLN) technique as a safe technique for use in patients with early-stage cervical cancer treated with SLNB only. Disease-free survival after 4 years was similar in patients treated with SLN biopsy and patients who underwent a lymphadenectomy.