Clinical possibility of detection of lung cancer micrometastasis in regional lymph nodes by reverse transcriptase-polymerase chain reaction

Abstract

To study the clinical possibility of detection of lung cancer micrometastasis in regional lymph nodes(LNs) by reverse transcriptase-polymerase chain reaction(RT-PCR). The CK19 mRNA was used as marker. Serial dilution for lung cancer tissues was performed to demonstrate the sensitivity of the method. Each LN was bisected. One half was subjected to routine histological examination(HE), and the other half of all LNs which were pooled was subjected to CK19 RT-PCR. The sensitivity of CK19RT-PCR method ranged from 1×10⁻⁶ to 1×10⁻⁴μg RNA of lung cancer tissue per 1μg RNA of normal LNs. Among 20 patients analyzed in this study, HE was done on each LN, which revealed LN metastasis in eight patients and these results were confirmed by CK19 RT-PCR. Of the other 12 patients who were diagnosed to be devoid of metastasis by HE, three patients were found to have micrometastasis in the regional LNs by RT-PCR. There was no significant difference between the detecting result of single LN and that of mixed LNs (P>0.05). Comparing with detecting single LN by RT-PCR, the sensitivity of RT-PCR for detection of micrometastasis in mixed LNs is remarkably higher than that of routine HE method. It can dramatically reduce the time and the cost of detection and can be applied clinically.