The sentinel node procedure in early stage cervical cancer, taking the next step; a diagnostic review

Recent reviews on the sentinel lymph node (SLN) procedure in cervical cancer have shown that bilateral SLN detection and ultra staging are safe and superior options compared to a unilateral detection, frozen section and H&E analysis. So far, nobody identified a subgroup of patients in whom a SLN procedure may replace pelvic lymph node dissection (PLND).

We searched PubMed, Embase, CINAHL and Cochrane from inception up to November 26, 2014. Studies reporting SLN detection, and/or histological outcome of the SLN were included. Methodological quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool by two independent reviewers. Data to complete 2×2 contingency tables were obtained, and patient-, study- and technique characteristics were extracted. Results were pooled and plotted in forest plots.

Forty-seven studies (4130 patients) were analyzed. Pooled data of diagnostic accuracy on ultra staging (18 studies; 1275 patients) showed a sensitivity of 94% (95% CI 80-99%) and negative predictive values ranging between 91 and 100%. After ultra staging, 19 false negative results remained. Prerequisites such as early FIGO stage (IA2, IB1, IIA primary tumor size <40mm), no suspicious pre-, and per-operative lymph nodes, and bilateral negative SLNs after ultra staging resulted in 1 remaining false negative result among 1257 patients (0.08%). Pooled data on a combined tracer in early stage cervical cancer patients with primary tumor size <20mm (6 studies; 276 patients) resulted in 87% bilateral SLN detection.

Early stage cervical cancer patients (FIGO IA2, IB1, IIA primary tumor size <40mm) who have no suspicious pre-, and per-operative lymph nodes, and have bilateral negative SLNs after ultra staging, have a residual risk of 0.08% (1/1257) on occult metastases. On the basis of these results we recommend not to perform a full PLND in these patients.