Potential risks in sentinel lymph node biopsy for cervical cancer: a single-institution pilot study

Sentinel lymph node (SLN) biopsy is an attractive technique that is widely performed in many oncological surgeries. However, the potential risks in SLN biopsy for cervical cancer remains largely unclear.

Seventy-five patients with histologically confirmed cervical cancer were enrolled between May 2014 and June 2016. SLN biopsies were performed followed by pelvic lymphadenectomies and all resected nodes were labeled according to their anatomic areas. Only bilateral detections of SLNs were considered successful. Patients' clinicopathologic feature, performance of SLN detection, and distributions of lymph node metastases were analyzed.

Of the 75 enrolled patients, at least one SLN was detected in 69 (92.0%), including 33 in bilateral and 36 in unilateral. SLNs were most detected in the obturator area (52 of 69 patients, 75.4%) and 26 (37.7%) patients presented SLNs in more than one area of hemipelvis. Lymphovascular invasion was found to be the only factor that adversely influenced SLN detection, while the tumor diameter, growth type, histological grade, deep stromal invasion, and neoadjuvant chemotherapy showed no significant impacts. Patients with lymphovascular invasion showed a significantly higher rate to have unsuccessful detection (90.9% versus 41.5%, P < 0.001) and lymph node metastasis (40.9% versus 3.8%, P < 0.001) compared with those without. Nodal metastases were confirmed in 11 patients, of whom 9 (81.8%) had lymphovascular invasion and 7 (63.6%) had non-SLN metastasis. The most frequently involved SLNs were obturator nodes (9/11, 81.8%). In addition, the parametrial nodes also have a high rate to be positive (4/11, 36.4%), although they were relatively less identified as SLNs. Besides, 3 patients showed metastases in the laterals without SLN detected.

In cervical cancer, lymphovascular invasion is a significant factor for unsuccessful SLN detection. The risk of having undetected metastasis is high when SLN is positive; therefore, further lymphadenectomy may be necessary for these patients.