Detection of occult metastases in lymph nodes from patients with colorectal carcinoma by reverse transcriptase-polymerase chain reaction / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To detect occult metastases in lymph nodes from patients with colorectal carcinoma and its clinical significance.</p><p><b>METHODS</b>The metastases in 260 lymph nodes from 39 histologically verified colorectal cancer patients were studied by both hematoxylin-eosin (HE) staining and cytokeratin-20 (CK20) specific RT-PCR. Ten normal lymph nodes were served as negative controls, and HT29 colon cancer cell line and 5 colorectal cancer specimens as positive controls.</p><p><b>RESULTS</b>Ten normal lymph nodes were CK20-negative, HT29 cells and 5 tumor specimens were all CK20-positive. All 29 lymph nodes from 16 patients which confirmed metastases by HE staining exhibited CK20 positive expression; an additional 28 lymph nodes from 5 patients with no histologically detectable metastases expressed CK20 mRNA, i.e. presence of metastases. The difference of the positivity was significant (11.1% vs 21.9%, P < 0.01). According to the HE staining, the cases of Dukes' A, B, C and D were 3, 20, 12 and 4, respectively. In the 20 patients of Dukes' B stage, 5 of them had CK20-positive lymph nodes.</p><p><b>CONCLUSION</b>CK20-specific RT-PCR is a highly sensitive, specific and simple method for detecting occult metastases in lymph nodes. The detection of CK20 mRNA expression in lymph nodes is recommended to precisely determine tumor stage and postoperative adjuvant therapy for patients with colorectal cancer, and further studies should be done in future to confirm the findings.</p>