Immunohistochemical detection of adhesion molecule CD44 splice variants in lymph node metastases of cervical cancer

Expression of specific cell adhesion molecule CD44 isoforms (splice variants) has been shown to be associated with poor prognosis in human cervical cancer. We used 3 different variant exon sequence-specific murine monoclonal antibodies (MAbs) to epitopes encoded by exons v5, v6 and v7-v8 of human variant CD44 to study the expression of CD44 splice variants in 35 primary squamous-cell carcinomas of the cervix and pelvic lymph node metastases by means of immunohistochemistry. Primary tumors showed expression of CD44 splice variants CD44v5, CD44v6 and CD44v7-8 in 93%, 73% and 33% of cases, respectively. Lymph node metastases expressed CD44v5, CD44v6 and CD44v7-8 in 83%, 53% and 21% of cases, respectively. Tumors with expression of CD44v6 in pelvic lymph node metastases showed metastatic spread to 2 or more pelvic lymph nodes significantly more often compared to patients without expression of splice variant CD44v6. Patients suffering from tumors with lymph node metastases expressing splice variant CD44v6 had a poorer recurrence-free survival compared to patients without CD44v6 expression in lymph node metastases, but this trend was not statistically significant. Expression of CD44 splice variants containing epitopes encoded by exon v6 in primary tumors and pelvic lymph node metastases of cervical cancer patients is consistent with a prominent role of CD44 in the process of metastasis formation.