Irregular expression of hyaluronan and its CD44 receptor is associated with metastatic phenotype in laryngeal squamous cell carcinoma

The distributions of hyaluronan (HA) and its CD44 receptor were studied in 24 normal, 27 dysplastic samples of laryngeal epithelium and in 172 squamou s cell carcinomas (LSCC), using a specific probe prepared from cartilage pr oteoglycan (bHABC, biotinylated hyaluronan binding complex) and a monoclona l antibody (Hermes 3). HA and CD44 were expressed similarly in all normal a nd about 90% of dysplastic and neoplastic laryngeal epithelia. In the norma l epithelium HA and CD44 were homogeneously distributed throughout the epit helium, whereas the most superficial layers were negative. This was in cont rast to the picture in dysplastic epithelium and well-differentiated invasi ve carcinomas, which were entirely HA and CD44 positive. Local areas with a low signal for HA and CD44 were present in 11% and 22% of the samples with dysplasia, and in 27% and 28% of those with carcinoma, respectively. The p resence of this staining irregularity was associated with poor differentiat ion of the carcinoma, a significantly elevated mitotic index and a high fre quency of nodal spreading and metastases. Furthermore, the irregular staini ng showed a trend towards poor disease-free survival, suggesting that an al tered metabolism of HA is a common feature in LSCC and is associated with a n aggressive growth pattern.