Abstract# 4993: LKB1 expression in primary and metastatic head and neck cancer

The tumor suppressor LKB1 is the third most frequently mutated gene in lung cancer, and is also associated with the development of epithelial carcinomas in Peutz-Jeghers patients. Inactivating mutations of LKB1 may promote tumorigenesis through aberrant cell polarization, up-regulated energy metabolism, and enhanced tumor cell migration and metastasis. LKB1 mutation positively correlates with tobacco carcinogen exposure and smoking status in lung cancer patients; however, little is known regarding the potential role of LKB1 in primary head-and-neck cancer or in its metastasis. In the current study, we analyzed LKB1 protein expression in primary tumor sections from head-and-neck cancer patients who never developed metastases (after a 5 year follow-up), as well as in primary and corresponding lymph node tumors from patients with metastatic disease. LKB1 staining intensity was graded on a scale of 0 to …