Detection of carbonic anhydrase 9-expressing tumor cells in the lymph nodes of vulvar carcinoma patients by RT-PCR.
Regional lymph node status is an important prognostic factor for vulvar cancer. The goal of our study was to elaborate a reliable test for detecting micrometastases, undetectable by traditional methods, in the lymph nodes of vulvar squamous carcinoma patients. For this purpose, carbonic anhydrase-9 (CA9) was investigated as a cancer-related marker by RT-PCR. Firstly, primary carcinoma specimens were examined for CA9 expression by immunohistochemistry with M75 monoclonal antibody. All 19 tissues exhibited a variable degree of staining, which was mostly confined to the plasma membranes of tumor cells. Correspondingly, all primary tumor specimens and the control A-431 vulvar cancer cell line gave a positive signal in the nested RT-PCR assay designed to detect CA9-expressing cells with a high sensitivity. Analysis of 77 lymph node specimens from 20 patients revealed a full correlation between RT-PCR results and standard hematoxylin-eosin staining in 75% of samples, whereas 25% of specimens were negative by the standard method and positive for CA9 mRNA, accounting for 28% of all histologically negative lymph nodes. There were no false-negatives with RT-PCR. A positive inguinal lymph node with a negative sentinel node was observed in the same groin only once in 38 specimens. Our findings clearly indicate potential value of CA9 as a molecular marker for the assessment of regional lymph node status in vulvar cancer patients and support a possible utility of our RT-PCR assay in the detection of micrometastases.
Kowalewska
Magdalena
M
Department of Molecular Biology, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland. magdak@coi.waw.pl
Radziszewski
Jakub
J
Kulik
Jadwiga
J
Barathova
Monika
M
Nasierowska-Guttmajer
Anna
A
Bidziński
Mariusz
M
Pastorek
Jaromir
J
Pastorekova
Silvia
S
Siedlecki
Janusz A
JA
D000951:Antigens, Neoplasm / Q000032:analysis / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000032:analysis / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D002478:Cells, Cultured; D017931:DNA Primers; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000201:enzymology* / Q000473:pathology; D008207:Lymphatic Metastasis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014846:Vulvar Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D017931:DNA Primers; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases