Low-Risk Thyroid Cancer in Elderly: Total Thyroidectomy/RAI Predominates but Lacks Survival Advantage.

ABSTRACT

BACKGROUND: Papillary thyroid cancer (PTC) is the fastest increasing cancer in the United States; incidence increases with age. It generally has a favorable prognosis but may behave more aggressively in older patients. This study aims to describe national treatment patterns for low-risk PTC in older adults. MATERIALS AND METHODS: The Surveillance, Epidemiology, and End Results-Medicare database was used to identify patients ≥66 y treated for clinical T1N0M0 PTC between 1996 and 2011. Multivariable logistic regression was used to identify factors associated with extent of surgery (total thyroidectomy versus lobectomy) and radioactive iodine (RAI) administration. Cox proportional hazards modeling was used to estimate the effect of treatment type on disease-specific survival (DSS). RESULTS: Three thousand two hundred and fourteen patients met inclusion criteria; 77.6% were women, median age was 72 y, and mean tumor size was 0.7 cm. 42.7% had preoperatively diagnosed PTC (versus incidental). 65.4% underwent total thyroidectomy, 29.0% lobectomy, and 5.6% lobectomy followed by completion thyroidectomy; 33.4% received postoperative RAI. Five- and 10-year DSS were 98.9% and 98.3%, respectively. After adjustment, larger tumor size (1.1-2 cm), multifocality, and a preoperative PTC diagnosis were associated with greater odds of undergoing more extensive surgery and receiving RAI (P < 0.0001). DSS was not associated with extent of surgery or RAI administration (P > 0.05). CONCLUSIONS: Most older adults with PTC underwent total thyroidectomy and a third received RAI; neither treatment improved DSS. In the growing elderly population, less extensive interventions for PTC may reduce morbidity and improve quality of life while preserving an excellent prognosis.