CERVICAL LYMPH-NODE INVOLVEMENT IN HEAD AND NECK-CANCER DETECTABLE ASEXPRESSION OF A SPLICED TRANSCRIPT OF TYPE-II KERATIN K5

Metastatic spread to cervical lymph nodes is a major determinant of ou tcome in head and neck cancer. One hundred and ninety-six lymph nodes dissected from fresh surgical specimens from 24 patients with primary head and neck squamous cell carcinoma (SCC) were bisected. Messenger R NA (mRNA) extracted from one half and from a segment of the primary tu mour was amplified by reverse transcriptase (RT)-polymerase chain reac tion (PCR) with primers flanking the fifth intron of human type II ker atin K5. DNA bands resolved by agarose gel electrophoresis were confir med as specific transcripts by sequencing. The other half of each node was fixed in formalin for histology and, in selected nodes, for immun ohistology for cytokeratins. Of 153 nodes suitable for analysis, 14 no des contained metastatic tumour detected by light microscopy and also tested positive for K5 mRNA by RT-PCR. Fifty-six nodes were histologic ally negative for tumour but positive for K5 mRNA, and 83 nodes were n egative for both histology and K5 mRNA. Extracts of the primary tumour always reacted positively for K5 by RT-PCR, whereas lymph nodes from patients without malignancies, and blood lymphocytes from a healthy vo lunteer reacted negatively. RT-PCR designed to detect the presence of processed transcripts of type II keratin K5 in stratified squamous epi thelial cells may be a sensitive technique to detect the presence of v iable and potentially metastatic carcinoma cells in lymph nodes draini ng head and neck SCC. (C) 1998 Elsevier Science Ltd. All rights reserv ed.