The sentinel node procedure for detection of pelvic lymph node metastases of uterine cervical cancer: A systematic review

Objectives The presence of pelvic lymph node metastases is an important factor for both prognosis and choice of treatment in patients with uterine cervical cancer. Therefore, ideally, one would like to stage the pelvic lymph nodes before starting treatment. Unfortunately, conventional imaging techniques have poor sensitivity. The sentinel node procedure (SNP) may produce better staging, but although several studies experimented with this technique most study populations are small. To overcome this problem we performed a meta-analysis.

Methods The literature was searched for studies performing SNP as well as a pelvic lymphadenectomy in patients with newly diagnosed uterine cervical cancer.

Results 36 studies, investigating a total of 1,958 patients (mean: 54), were identified. The overall detection rate (identification of at least one SN) was 87% (83% for blue dye only, 87% for isotope only, 93% for isotope and blue dye). The overall presence of pelvic lymph node metastases was 42% in these patients. The false-negative rate of the SNP was 3.2% (95%CI: 2.4%-4.1%). Of 76 true positives with more detailed information available, 38% had microscopic disease only. Of 159 patients with no SN detected 38% had pelvic lymph node metastases. Of 12 false negatives with more detailed information, 8 had a metastasis on the side where no SN was detected, and 4 had parametrial metastases.

Conclusions The SNP has an excellent detection rate, especially if blue dye and an isotope are combined. The technique can detect micro-metastases, which are notoriously diffucult to detect. In this large population the false negative rate was around 3%.