Diagnostic value of frozen section examination of sentinel lymph nodes in early-stage cervical cancer at the time of ultrastaging

Objectives: We aimed to assess the diagnostic value of frozen-section pathologic examination (FSE) of sentinel lymph nodes (SLN) in patients with early-stage cervical cancer.

Methods: Two French prospective multicentric database on SLN biopsy for cervical cancer (SENTICOL I and II) were analysed. Patients with IA to IIA1 2018 FIGO stage, who underwent SLN biopsy with both FSE and ultrastaging examination were included.

Results and discussion: Between 2005 and 2012, 313 patients from 25 centers fulfilled the inclusion criteria. Metastatic involvement of SLN was diagnosed in 52 patients (16.6%). Macrometastases, micrometastases and isolated tumor cells (ITCs) were found in 27, 12 and 13 patients respectively. Among the 928 SLNs analysed, FSE identified 23 SLNs with macrometastases in 20 patients and 5 SLNs with micrometastases in 2 patients whereas no ITCs were identified. Ultrastaging of negative SLNs by FSE found macrometastases, micrometastases and ITCs in additional 7, 11 and 17 SLNs. Ultrastaging increased significantly the rate of patients with positive SLN from 7% to 16.6% (p < 0.0001). The sensitivity and the negative predictive value of FSE were 42.3% and 89.7% respectively or 56.4% and 94.1% if ITCs were excluded. False-negative cases were more frequent with tumor size ≥ 20 mm (OR = 4.46, 95%IC = [1.45-13.66], p = 0.01) and preoperative brachytherapy (OR = 4.47, 95%IC = [1.37-14.63], p = 0.01) and less frequent with patients included in higher volume center (>5 patients/year) (OR = 0.09, 95%IC = [0.02-0.51], p = 0.01).

Conclusions: FSE of SLN had a low sensitivity for detecting micrometastases and ITCs and a high negative predictive value for SLN status. Clinical impact of false-negative cases has to be assessed by further studies.