Genetic predisposition to endocrine tumors: Diagnosis, surveillance and challenges in care

Endocrine tumor syndromes, eg, multiple endocrine neoplasia types 1 and 2, were among the first recognized hereditary predisposition syndromes to tumor development. Over time, the number of endocrine tumor syndromes has significantly expanded, eg, with the recent inclusion of hereditary paraganglioma syndromes. Associations of non-endocrine tumors with hereditary endocrine tumor syndromes and endocrine tumors with non-classical endocrine tumor syndromes have emerged. These findings have certainly expanded the scope of care, necessitating a multidisciplinary approach by a team of medical professionals and researchers, integrating shared patient decision-making at every step of surveillance, diagnosis, and treatment. In the absence of evidence-based guidelines, multiple aspects of patient care remain individualized, based on a patient's clinical presentation and family pedigree. This is particularly important when determining a surveillance plan for unaffected or disease-free mutation carriers. In this review, we describe the main endocrine tumor manifestations found in familial cancer syndromes in an organ-based approach, focusing on adrenocortical carcinoma, pheochromocytoma and paraganglioma, neuroendocrine tumors, differentiated thyroid cancer, and medullary thyroid cancer. We highlight the challenges in diagnosis, surveillance, and therapy unique to the patient population with hereditary syndromes. Furthermore, we underscore the importance of evaluating for genetic predisposition to tumor development, provide features that can identify index patients, and discuss the approach to screening surveillance for mutation carriers.