Central Pathology Review in SENTIX, A Prospective Observational International Study on Sentinel Lymph Node Biopsy in Patients with Early-Stage Cervical Cancer (ENGOT-CX2)

Diagnostic performance of ultrasonography in pre-operative assessment of lymph nodes in patients with cervical cancer

OBJECTIVES

To assess the diagnostic performance of ultrasonography in pre-operative assessment of lymph nodes in patients with cervical cancer, to compare the outcomes for pelvic and para-aortic regions, and to detect macrometastases and micrometastases separately.

METHODS

Patients were retrospectively included if they met the following inclusion criteria: pathologically verified cervical cancer; ultrasonography performed by one of four experienced sonographers; surgical lymph node staging, at least in the pelvic region-sentinel lymph node biopsy or systematic pelvic lymphadenectomy or debulking. The final pathological examination was the reference standard.

RESULTS

390 patients met the inclusion criteria between 2009 and 2019. Pelvic node macrometastases (≥2 mm) were confirmed in 54 patients (13.8%), and micrometastases (≥0.2 mm and <2 mm) in another 21 patients (5.4%). Ultrasonography had sensitivity 72.2%, specificity 94.0%, and area under the curve (AUC) 0.831 to detect pelvic macrometastases, while sensitivity 53.3%, specificity 94.0%, and AUC 0.737 to detect both pelvic macrometastases and micrometastases (pN1). Ultrasonography failed to detect pelvic micrometastases, with sensitivity 19.2%, specificity 85.2%, and AUC 0.522. There was no significant impact of body mass index on diagnostic accuracy. Metastases in para-aortic nodes (macrometastases only) were confirmed in 16 of 71 patients who underwent para-aortic lymphadenectomy. Ultrasonography yielded sensitivity 56.3%, specificity 98.2%, and AUC 0.772 to identify para-aortic node macrometastases.

CONCLUSION

Ultrasonography performed by an experienced sonographer can be considered a sufficient diagnostic tool for pre-operative assessment of lymph nodes in patients with cervical cancer, showing similar diagnostic accuracy in detection of pelvic macrometastases as reported for other imaging methods (18F-fluorodeoxyglucose positron emission tomography/CT or diffusion-weighted imaging/MRI). It had low sensitivity for detection of small-volume macrometastases (largest diameter <5 mm) and micrometastases. The accuracy of para-aortic assessment was comparable to that for pelvic lymph nodes, and assessment of the para-aortic region should be an inseparable part of the examination protocol.

Sentinel lymph node pathological ultrastaging: Final outcome of the Sentix prospective international study in patients with early-stage cervical cancer

OBJECTIVE

To report the outcome of SLN staging in the SENTIX international prospective trial of SLN biopsy in patients with cervical cancer with an intensive ultrastaging protocol and central quality control and to evaluate how the intensity of pathological assessment correlates with metastatic detection rate in SLNs.

METHODS

Eligible were patients with stages T1a1/LVSI+ to T1b2 (<4 cm, ≤2 cm for fertility sparing), common tumor types, no suspicious lymph nodes on imaging, and bilateral SLN detection. SLNs were examined intraoperatively and processed by an intensive protocol for ultrastaging (paraffin blocks sectioned completely in 150-μm intervals/levels). SLNs from each site were submitted for central quality control.

RESULTS

In the SENTIX SLN study, 647 out of 733 enrolled patients underwent SLN ultrastaging, identifying 12.5% (81/647) with node positive, N1 cases. Intraoperative detection revealed metastases in 56.8% (46/81) of these cases, categorized into macrometastases (83.7%), micrometastases (26.3%), and isolated tumor cells (9.1%). Ultrastaging identified additional metastatic involvement in 43.2% (35/81) of patients, with detailed sectioning revealing metastases (MAC/MIC) at first level in 20 cases (24.7%), at levels 2-4 in 9 cases (11.1%), and at level ≥5 in 6 cases (7.4%).

CONCLUSION

SLN ultrastaging detects additional 43% of N1 (MAC/MIC) in patients with negative LNs by imaging and intraoperative pathological assessment. The detection rate of positive SLN correlates with the intensity (number of levels) of ultrastaging. Examination of four levels from paraffin blocks, which detects >90% of patients with N1, is a reasonable compromise for an international standard for ultrastaging.

STUDY REGISTRATION

NCT02494063 (ClinicalTrials.gov).

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.

Value of sentinel node ultrastaging and pathologic techniques in tumoral detection

PURPOSE OF REVIEW

Sentinel lymph node assessment is an option for patients with clinically early-stage vulvar cancer, endometrial cancer, cervical cancer, and, more recently, ovarian cancer. However, although ultrastaging is mandatory as part of the node evaluation, universally accepted pathology protocols are lacking. This review focuses on the current evidence for the most relevant aspects of sentinel lymph node evaluation, as well as some controversial topics like frozen section or one-step nucleic acid amplification.

RECENT FINDINGS

The diagnostic accuracy of sentinel lymph node detection algorithms for patients with gynecologic neoplasms is high. However, the heterogeneity among the published studies and the absence of clear recommendations from most guidelines make it challenging to recommend one protocol over another. The minimum requirement from ultrastaging protocols (regarding the number of levels to be assessed, among others) to get the highest accuracy with a minor cost is unknown.

SUMMARY

Sentinel lymph node evaluation is now part of the surgical management for most early-stage gynecologic neoplasms. However, a universally accepted ultrastaging pathology protocol is lacking in literature and clinical practice. This gap requires significant effort from the gynecologic oncology and pathology community to be closed and then to allow advancements in surgical management for early-stage gynecologic tumors to go forward.

Therapies in Cervical Cancer-Editorial

George Papanikolaou is famously quoted as saying "the first observation of cancer cells in the smear of the uterine cervix gave me one of the greatest thrills I ever experienced during my scientific career" [...].

Para-aortic lymph node involvement in cervical cancer: Implications for staging, outcome and treatment

Locally advanced cervical cancer with the involvement of para-aortic lymph nodes (PALN) is a common occurrence in low-income and low-middle-income countries. With the incorporation of PALN in the recent FIGO staging, therapeutic management becomes crucial. There are varied presentations of this group which may range from microscopic involvement to extensive lymphadenopathy. Various imaging modalities have been studied to accurately diagnose PALN metastases without surgical intervention, while some investigators have studied the survival benefit of para-aortic lymph node dissection for accurate staging and guiding extent of radiation. With recent advances in radiation therapy, its application to treat bulky nodal metastases and the role of prophylactic irradiation have been reported. In this review, the available evidence and the scope of further interventions is presented.

The Cervical Cancer Research Network (Gynecologic Cancer InterGroup) roadmap to expand research in low- and middle-income countries

Cervical cancer is a global health problem which disproportionally affects women in low- and middle- income countries. The World Health Organization recently launched its global strategy to eliminate this disease in the next two decades. For those women diagnosed today with cervical cancer better strategies are needed to improve outcome and reduce treatment-related morbidity. Clinical trials are critical to shaping future treatment, and much has been achieved already. However, such opportunities are limited in low resource settings, and the Cervical Cancer Research Network is dedicated to expanding access to new technologies in surgery, radiation, and medical oncology. In this article we review the status of the trials portfolio and outline future objectives, including the launch of a number of research grants for aspiring or established researchers in low- and middle-income settings.