A preliminary study on the detection of lymph node metastasis in cervical cancer using a quantitative RT-PCR assay

This preliminary study aimed to assess the detection accuracy of sentinel lymph node metastasis in cervical cancer using quantitative reverse transcriptase-polymerase chain reaction.

We collected cervical cancer tissues and 70 pelvic lymph node samples from patients with cervical cancer. The quantitative reverse transcriptase-polymerase chain reaction assay was performed to investigate the expression of cytokeratin 19 mRNA in cervical cancer tissues and determine the cutoff value of cytokeratin 19 mRNA between the non-metastatic and metastatic lymph nodes.

The expression of cytokeratin 19 mRNA in cancer tissues was detected in all (71/71) the tumours, with a median copy number of 7.56 × 105/μl of RNA by quantitative reverse transcriptase-polymerase chain reaction. Sixteen lymph nodes were diagnosed as positive by pathological examination. The median copy numbers of cytokeratin 19 mRNA for positive and negative lymph nodes were 43.3 × 104/μl and 121.1/μl, respectively. The expression of cytokeratin 19 mRNA in pathologically positive lymph nodes was higher than that in the negative lymph nodes (P < 0.0001) by quantitative reverse transcriptase-polymerase chain reaction analysis. Using a receiver operating characteristic plot, the maximum sensitivity (100%) and specificity (94.4%) were obtained when the cutoff value was set at 1169 copies/μl.

After setting the cutoff value at 1169 copies/μl, a quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA showed high accuracy in detecting lymph node metastasis in cervical cancer. We believe that the quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA may be acceptable for lymph node metastasis detection in patients with cervical cancer.