Intrinsic variability in the detection of micrometastases in lymph nodes for re-staging of colorectal cancer: effect of individual markers and tissue samples

Salto-Tellez, M; Kong, S.L; Leong, A.P.K; Koay, E.S.C

doi:10.1016/S0959-8049(03)00231-4

« Previous Next »European Journal of Cancer
Volume 39, Issue 9 , Pages 1234-1241, June 2003

Intrinsic variability in the detection of micrometastases in lymph nodes for re-staging of colorectal cancer:

effect of individual markers and tissue samples

M Salto-Tellez
- Department of Pathology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore²
- Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, 5 Kent Ridge Road, Singapore 119074, Singapore
- Both these authors contributed equally to this paper.
S.L Kong
- Department of Pathology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore²
- Both these authors contributed equally to this paper.
A.P.K Leong
- Department of Surgery, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
E.S.C Koay
- Department of Pathology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore²
- Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, 5 Kent Ridge Road, Singapore 119074, Singapore
- Corresponding author. Tel.: +65-6772-4564; fax: 65-6778-0671

Received 10 July 2002; accepted 6 January 2003.

Abstract

In this study, we investigated whether (a) carcinoembryonic antigen (CEA), cytokeratin-20 (CK-20) and guanylyl cyclase C (GCC) are clinically useful markers for the molecular detection of submicroscopic metastases in colorectal cancer (CRC) and (b) whether overexpression of CEA, CK-20 and GCC can be reliably detected in formalin-fixed, paraffin-embedded tissues as well as frozen lymph nodes. We studied 175 frozen lymph nodes and 158 formalin-fixed, paraffin-embedded lymph nodes from 28 cases of CRC. CEA or CK-20 or GCC-specific polymerase chain reaction (PCR) was carried out on mRNA transcripts extracted from the nodal tissues. Ten out of 11 Dukes' B CRC cases had detectable CEA and CK-20 while 6 out of 11 Dukes' B CRC cases had detectable GCC. In general, the difference of re-staged cases when comparing frozen and paraffin-embedded samples was marked; the only statistically significant correlation between frozen and paraffin tissue was for the CEA marker. Our results indicated a high incidence (>50%) of detecting micrometastases in histologically-negative lymph nodes at the molecular level.

Keywords: Micrometastases, Colorectal cancer, Lymph nodes, CEA, CK-20, GCC