Detection of micrometastases and its clinical significance in sentinel and non-sentinel lymph nodes from early cervical carcinoma

Abstract

To investigate the clinical significance of micrometastasis detection in sentinel lymph nodes (SLN) from patients with early cervical carcinoma. Thirty patients with early cervical carcinoma were studied to identify SLN intraoperatively using methylene blue. One lymph node was removed randomly from palpable SLN and other pelvic lymph nodes (nSLN) in each patient, so 268 lymph nodes were collected and cut into two halves, one half of the lymph node was used to analyze the expression of cytokeratin 19 (CK19) mRNA by real-time fluorescence quantitative polymerase chain reaction to determine the presence of micrometastasis, the other half was examined by routine histology with HE staining. 67 SLNs were detected in 28 cases (93.3%). Pelvic lymph nodes of 6 cases were confirmed pathological metastasis. The sensitivity of SLN detection was 66.7%, the accuracy rate was 96.4%, and the false negative rate was 16.7%. Among 268 lymph nodes (including 9 lymph nodes with pathological metastasis) detected by real-time fluorescence quantitative polymerase chain reaction, 68 lymph nodes were pathological negative but had micrometastasis, accounting for 26.3% (68/259) in pathologically negative lymph nodes. Among 24 patients with pathological negative lymph nodes, 16 cases had micrometastasis, accounting for 66.7% in those patients. Among 16 patients with micrometastasis, SLN of 3 cases were negative, but nSLN were micrometastasis, so the SLN false-negative rate rose to 18.2%. There were no significant relationships between pelvic lymph nodes micrometastasis and perivascular space involvement, deep stromal invasion and tumor grade (all P > 0.05). The micrometastasis rate of nSLN in patients with SLN micrometastasis was 100%, significantly higher than that in the patients with SLN non-micrometastasis (27.3%, P < 0.01). Real-time fluorescence quantitative polymerase chain reaction is a sensitive method to detect SLN micrometastasis. SLN micrometastasis may be an effective complement to SLN pathology to predict nSLN metastasis. Pelvic lymph nodes micrometastases have no significant relationship with pathological risk factors in cervical cancer and prognosis of patients.