Prognostic implications of site of recurrence in patients with recurrent well-differentiated thyroid cancer

The site of treatment failure in patients with recurrent well-differentiated thyroid carcinoma (WDTC) has implications for both the mode of salvage therapy and disease-specific prognosis. The objective of this study was to evaluate the prognostic significance of the site of failure in patients with recurrent WDTC.

Patients with recurrent thyroid cancer were identified retrospectively from 1963 to 2000.

Data were retrieved from the thyroid cancer database at the Department of Otolaryngology-Head and Neck Surgery, Mount Sinai Hospital, Toronto (1963-2000).

Patients were placed into four different groups according to their site of recurrence: group 1, local recurrence; group 2, regional recurrence; group 3, distant recurrence; and group 4, unspecified recurrence. Patient, tumour, and treatment data were collected and compared. The Kaplan-Meier method was used to calculate survival data, and curves were compared using the log rank test.

Outcome included alive, no disease; alive with disease; dead, no disease; and dead of disease.

Seventy-three patients (21 male, 52 female; median age 44 years, range 18-84 years) were eligible for inclusion in this study. Relevant data were divided according to group 1, 22 patients; group 2, 24 patients; group 3, 13 patients; and group 4, 14 patients. The groups were comparable in terms of primary tumour and treatment factors. The actuarial disease-specific survival rate after salvage therapy was less significant in patients who developed a distant recurrence versus a local recurrence, a regional recurrence, or an unspecified recurrence (ie, 66% vs 95%, 88%, and 92%, respectively; p = .06).

Patients with distant recurrences have a poor prognosis, with a significant reduction in the actuarial disease-specific survival rate.