Thyroid Disorders in the Oncology Patient

Abstract

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.

Elevated Free Thyroxine Levels Are Associated with Poorer Overall Survival in Patients with Gastroesophageal Cancer: A Retrospective Single Center Analysis

“…However, one can surmise that chemotherapy might be a risk factor for thyroid disorders, since more than 12% of our study population developed hyperthyroidism (17 patients) or hypothyroidism (15 patients) during the course of cancer therapy. This assumption is in line with the findings of other trials [22,[26][27][28].There were also no changes of survival outcomes in correlation with the treatment of thyroid disorders.…”

Genome‐wide association studies of toxicity to oxaliplatin and fluoropyrimidine chemotherapy with or without cetuximab in 1800 patients with advanced colorectal cancer

“…rs13260246 maps to, and is an eQTL for, SLC26A7 , which functions as a Cl − /HCO 3 − exchanger and chloride channel, 32 and is expressed in several tissues including the thyroid. Chemotherapy can cause thyroid dysfunction and response to treatment may be affected by pre‐existing thyroid conditions 33‐35 . SLC26A7 is also expressed in parietal cells and genetic deletion results in decreased gastric acid secretion 36,37 .…”

Subsequent primary malignancies after diffuse large B‐cell lymphoma in the modern treatment era

“…While increased rates of incidental detection with more sensitive imaging tools and more frequent use of ultrasound could explain some of the incidence increase, we would also expect more sensitive imaging to detect other solid tumours, which we did not observe. Multiple studies have found positive associations between radiation therapy, but not chemotherapy (Meadows et al , ), and the risk for subsequent thyroid cancer after a diagnosis of head and neck cancer, AML, or HL (Ron et al , ; Meadows et al , ; Tolisano et al , ), and some studies have described thyroid disorders associated with rituximab use (Raterman et al , ; Hartmann, ). Our findings suggest that the increased risk of thyroid cancer post‐rituximab occurred in DLBCL patients with either localized/regional or advanced stage disease regardless of radiation therapy use.…”