Expression of variant CD44, exon 6 in patients with metastatic pulmonary tumor

High expression ratios of CD44 variant 6 (CD44 V6) in patients with metastatic pulmonary tumor were found in those with primary lesions of cancer of the colon, uterus, larynx, liver and osteosarcoma. It was clarified that patients showing expression of CD44 variant 6 likely revealed pulmonary metastasis at earlier time following operations of primary cancer (p<0.05). CD44 V6, an adhesion molecule, was a factor to participate in pulmonary metastases from various organ cancers. No significant correlation was observed in survival between patients with CD44 V6 positive versus negative tumors, except laryngeal tumor after resection of primary or metastatic lung tumor. CD44 V6 related to its invasive and further metastatic functions in metastatic lung tumor. We suggest that cancer cells expressing the CD44 molecule especially V6 may adhere to vascular endothelium and hyaluronic acid in the lung. And cancer cells without this molecule liberated from the primary focuses hardly adhere to the pulmonary tissues supposedly resulting in delayed metastases and proliferations in the pulmonary tissues.