Effect of Thyroid-Related Symptoms on Long-Term Quality of Life in Patients with Differentiated Thyroid Carcinoma: A Population-Based Study in Sweden.

BACKGROUND

Differentiated thyroid cancer (DTC) has a good prognosis but a remaining risk of recurrence, and life-long follow-up as well as medication with levothyroxine may be necessary. The aim of this study was to clarify how thyroid-related symptoms affect health-related quality of life (HRQoL) 14-17 years after diagnosis in Swedish DTC patients.

METHODS

From the all-encompassing population-based Swedish Cancer Registry, 353 patients diagnosed with DTC during 1995-1998 were identified and invited to answer a study-specific questionnaire and the HRQoL questionnaire SF-36 14-17 years after their diagnosis. Subgroups were studied according to thyroid-related symptoms, both symptoms correlated to thyroid disease or levothyroxine treatment and side effects from surgery and radioiodine treatment.

RESULTS

Of the patients with DTC, 279 (79%) answered the questionnaires. In all, only 19 (7%) reported a recurrence. Patients with one single symptom (e.g., fatigue, sleeping disorders, irritability, lower stress resistance, muscle weakness, bodily restlessness, sweating, palpitations, or flushes) had significantly lower HRQoL measured with the SF-36 compared to those without that specific symptom (p < 0.001). Furthermore, those 238 patients with at least one symptom, regardless of which one, had significantly lower HRQoL in all eight SF-36 domains compared to patients that no thyroid symptom (n = 34; p < 0.001). In seven patients, the questionnaires were not complete in terms of the thyroid-related questions. The association between thyroid symptoms and lower HRQoL remained after adjusting for age, sex, comorbidities, education, and menopause.

CONCLUSIONS

DTC patients reporting thyroid symptoms scored lower in HRQoL compared to those with no symptoms >14 years after diagnosis.