Oral mucosal stigmata in hereditary-cancer syndromes: From germline mutations to distinctive clinical phenotypes and tailored therapies

• Several familial-cancer syndromes include distinctive oral mucosal lesions.
• Their genetic background involves germline mutations in tumor suppressor genes.
• A multidisciplinary approach is crucial for management of the gene-carriers probands.
• An early onset of oral disease may lead to genetic testing in suspected probands.
• The advancements in this field lead to the development of targeted therapies.

Numerous familial tumor syndromes are associated with distinctive oral mucosal findings, which may make possible an early diagnosis as an efficacious marker for the risk of developing visceral malignancies. In detail, Familial Adenomatous Polyposis (FAP), Gardner syndrome, Peutz–Jeghers syndrome, Cowden Syndrome, Gorlin Syndrome, Lynch/Muir–Torre Syndrome and Multiple Endocrine Neoplasia show specific lesions of the oral mucosa and other distinct clinical and molecular features. The common genetic background of the above mentioned syndromes involve germline mutations in tumor suppressor genes, such as APC, PTEN, PTCH1, STK11, RET, clearly implied in both ectodermal and mesodermal differentiation, being the oral mucosal and dental stigmata frequently associated in the specific clinical phenotypes. The oral and maxillofacial manifestations of these syndromes may become visible several years before the intestinal lesions, constituting a clinical marker that is predictive for the development of intestinal polyps and/or other visceral malignancies. A multidisciplinary approach is therefore necessary for both clinical diagnosis and management of the gene-carriers probands and their family members who have to be referred for genetic testing or have to be investigated for the presence of visceral cancers.