Impact of cytokeratin-20 and carcinoembryonic antigen mRNA detection by RT-PCR in regional lymph nodes of patients with colorectal cancer

The reported rates for tumour cell involvement in the locoregional lymph no des of colorectal cancer vary greatly, depending on the method used and cas e selection. In order to further evaluate the clinical value of molecular b iologic detection of tumour cells we investigated 102 histologically tumour -free (pNO) regional lymph nodes from 51 consecutive, completely resecled ( UICC RO) colorectal carcinoma specimens for the presence of tumour cell mRN A by RT-PCR specific for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20). Two lymph nodes located nearest to the primary tumour were investig ated in each case. CK-20 mRNA was found in 31 of 51 patients (60.8%) and CE A mRNA in 30 of 51 patients (58.8%), respectively. Identical transcription patterns of CK-20 and CEA mRNA (both positive or both negative) were found in 38 of 51 patients (74.5%). There was a significantly higher proportion o f cases with CEA positivity in the lymph nodes of tubulopapillary than of m ucinous adenocarcinomas (P < 0.03). Detection of CK-20 and CEA mRNA correla ted in nine of 12 cases (75.0%) with the risk of tumour recurrence (not sig nificant) and showed a tendency towards shorter disease-free survival by un ivariate analysis (not significant). Our data indicate that CK-20 and CEA m RNA detection by RT-PCR may prove useful for the prediction of tumour recur rence of patients with pNO colorectal carcinoma, although neither reach sta tistical significance in this series of patients. (C) 2000 Cancer Research Campaign.