PTEN hamartoma tumor syndrome: clinical risk assessment and management protocol.

The tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is an important phosphatase that counteracts one of the most critical cancer pathways: the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathways. Clinically, deregulation of PTEN function resulting in reduced PTEN expression and activity is implicated in human diseases. Cowden syndrome (CS) is an autosomal dominant disorder characterized by benign and malignant tumors. CS-related individual features occur commonly in the general population. Approximately 25% of patients diagnosed with CS have pathogenic germline PTEN mutations, which increase lifetime risks of breast, thyroid, uterine, renal and other cancers. PTEN testing and intensive cancer surveillance allow for early detection and treatment of these cancers for mutation positive patients and their relatives. In this review, we highlight our current knowledge of germline PTEN mutations in relation to human disease. We review current clinical diagnosis and management recommendations for PHTS including recent discoveries in understanding PTEN function regulation and how this can be exploited therapeutically.