Thyroid Disorders in the Oncology Patient

Thyroid disease and cancer diagnoses are common conditions likely to coexist. Optimal management requires appropriate diagnostic testing and consideration of a number of factors, including overall health status and prognosis. Hypothyroidism and hyperthyroidism can lead to a number of symptoms that may affect not only quality of life but can interfere with the patient's ability to tolerate cancer treatment. Imaging studies performed for cancer staging can identify incidental structural abnormalities in the thyroid, which should be assessed with dedicated neck ultrasonography and possibly fine-needle aspiration. Incidental thyroid cancer is most often less urgent than the patient's presenting malignancy and can be addressed surgically when appropriate in the context of other treatments (i.e., chemotherapy). Providers working in an oncology setting, as well as primary care providers, should be aware of medications that are associated with hormonal abnormalities. Any patient with a history of neck or brain radiation therapy is at risk of developing hypothyroidism and possibly other endocrinopathies. Complex or very ill patients may benefit from a multidisciplinary approach that utilizes the experience of a knowledgeable endocrinologist.