Long-term results in elderly patients with differentiated thyroid carcinoma

Background: The authors assessed the biologic behavior of differentiated thyroid carcinoma in patients age 70 years or older and evaluated factors that influenced long-term survival.

Methods: Among 1448 patients with differentiated thyroid carcinoma who were treated at the authors' institution over the past 60 years, 111 patients were identified who were age 70 years or older at the time of their initial diagnosis (range, 70-93 years). The authors conducted a retrospective analysis of the outcome of these 111 patients, who had a median follow-up of 9 years (range, 2-9 years).

Results: There were 83 female patients and 28 male patients (female to male ratio, 3:1). Fifty-eight tumors were papillary, 46 tumors were follicular, and 7 tumors were Hürthle cell carcinoma. Eighty percent of patients presented with a thyroid mass, and 70% of tumors were pathologic stage T3 (pT3) or pT4. Lymph node disease was evident at presentation in 44% of patients, and distant metastases were documented at diagnosis in 23% of patients. Forty-six patients underwent total thyroidectomy, and the remaining patients underwent subtotal thyroidectomy or biopsy only. Radioiodine was administered to 80 patients, and external beam radiotherapy was administered to 19 patients. The cause specific survival rates were 75%, 50%, and 50% at 5 years, 10 years, and 15 years, respectively. Multivariate analysis showed that the presence of metastases was the most important independent prognostic factor for survival. External beam radiotherapy was associated with a poorer prognosis, in that it was reserved for patients with either inoperable disease or residual disease after surgery and patients with no uptake of radioiodine.

Conclusions: A large proportion of thyroid tumors showed extrathyroid spread and distant metastases, which frequently were not iodine-avid. The prevalent histologic type was papillary, often with features of poor differentiation. Thyroid carcinoma in the elderly appears to behave more aggressively, and they have a less favorable prognosis compared with younger adults.