Quantitative RT-PCR Assay for Detecting Lymph Node Metastasis in Endometrial Cancer: A Preliminary Study

Abstract

Objective: The detection accuracy of sentinel lymph node (SLN) metastasis by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for endometrial cancer (EC) remains unclear and was assessed in this preliminary study. Methods: We studied primary cancer tissues and pelvic lymph nodes (PLN) from 105 patients with EC. qRT-PCR assay was performed to determine the copy numbers of CK19 mRNA in EC tissues, and negative and positive LN samples. Further, qRT-PCR results were compared with pathological findings. Results: CK19 mRNA expression was detected in 98% (104/106) of the tumors, with a median copy number of 3.0 × 10⁵/μL. Twelve LN were diagnosed as positive by pathological examination. The median copy number of CK19 mRNA for positive and negative LN was 8.1 × 10⁴/μL and 90.4/µL, respectively. CK19 mRNA expression was higher in pathologically positive LN than in pathologically negative LN (p < 0.01); the pathological and qRT-PCR findings showed no discrepancy. When the cutoff value was set at 4,500 copies/µL, qRT-PCR assay using CK19 mRNA exhibited high sensitivity and specificity. Conclusions: Our results demonstrated that qRT-PCR assay, using CK19 mRNA, exhibits a high accuracy for detecting LN metastasis in EC and represents a useful alternative to conventional pathological diagnosis of EC.