Detection of epidermal growth factor receptor mRNA in peripheral blood of cervical cancer patients

Abstract

Objective Epidermal growth factor receptor (EGFR) has been reported to be expressed by immunohistochemistry in invasive cervical cancers. We evaluated the feasibility of detecting EGFR mRNA by EGFR-based reverse transcription polymerase chain reaction (RT-PCR) in peripheral blood of patients with cervical cancer. Methods Expression of EGFR mRNA, cytokeratin (CK)-19 mRNA, and CK-20 mRNA was examined by RT-PCR in 12 human cervical cancer cell lines. All 12 cell lines expressed both EGFR mRNA and CK-19 mRNA, but only 4 of 12 (33.3%) cell lines expressed CK-20 mRNA. Peripheral blood samples from 20 healthy donors and 45 cervical cancer patients were also examined. Results In peripheral blood from 20 healthy donors, neither EGFR mRNA nor CK-20 mRNA was expressed, but CK-19 mRNA was expressed in 13 of 20 (65%). In contrast, EGFR mRNA was expressed in 12 of 45 (26.7%) patients with cervical cancer ( P = 0.0071, χ 2 test, patient vs control). On the other hand, expression of EGFR was observed in 98% of tumor tissues by immunohistochemistry. CK-19 mRNA and CK-20 mRNA were found in 35 of 45 (77.8%) and 0 of 45 (0%) patients, respectively (NS, χ 2 test, patient vs control). The rate of detection of EGFR mRNA in peripheral blood correlated with FIGO stage ( P = 0.049). Conclusion Both CK-19 mRNA and CK-20 mRNA showed no diagnostic value as markers of circulating tumor cells in cervical cancers. However, EGFR mRNA in blood might be a useful marker of circulating tumor cells in cervical cancers.