Background: The AMES (age, distant metastasis, tumor extent, and size), AGES (age, tumor size, histologic grade, tumor extent, distant metastasis), and MACIS (distant metastasis, age, completeness of primary tumor resection, local invasion, and tumor size) prognostic systems for well-differentiated thyroid carcinoma (WDTC) are well known. The development of disease recurrence is associated with a poor outcome; however, the prognostic importance of multiple treatment failures has not been clearly reported.
Objectives: To identify patient, tumor, and treatment factors that may be associated with the development of multiple recurrences in WDTC.
Design and setting: All patients treated for residual or recurrent WDTC were retrospectively identified from the thyroid cancer database at the Department of Otolaryngology-Head and Neck Surgery, Mount Sinai Hospital, Toronto, Ontario (1963-2000). Data on relevant patient, tumor, and treatment factors were collected.
Main outcome measures: Patient, tumor, and treatment factors predicting the development of multiple treatment failures, disease-specific survival, and overall survival.
Results: A total of 574 patients (115 male, 459 female; median age, 42 years [range, 9-92 years]) were identified, whose final histopathologic diagnosis was papillary carcinoma in 468, follicular carcinoma in 76, and mixed in 30 cases. TNM staging was as follows: 409 (71%) stage I, 66 (12%) stage II, 68 (12%) stage III, and 31 (5%) stage IV. Initial management included total thyroidectomy for 217 patients (38%), subtotal thyroidectomy for 357 (62%), and adjuvant iodine 131 therapy for 492 (86%). Seventy-three patients (13%) developed recurrent WDTC (21 male, 52 female; median age, 44 years [range, 18-84 years]). Patients were divided into 3 groups: group 1 (no recurrence, n = 501), group 2 (1 recurrence only, n = 42), and group 3 (multiple recurrences, n = 31). Group 2 data were as follows: site of recurrence (locoregional, 25; distant, 7; unspecified, 10) and treatment (surgery, 12; iodine 131, 42) and for group 3: site of first recurrence (locoregional, 16; distant, 11; unspecified, 4) and treatment (surgery, 14, iodine 131, 22; palliation, 1). Actuarial disease-specific survival at 20 years was 100%, 94%, and 60%, respectively, for the 3 groups (median follow-up, 7 years; range, 1-34 years). Male sex, advanced stage, extrathyroidal spread, and primary treatment with total thyroidectomy were predictive factors for multiple recurrences on multivariate regression (all P<.05).
Conclusions: Male sex, advanced initial stage, and presence of extrathyroidal spread within the primary tumor are the most significant independent predictors of developing multiple recurrences in patients with WDTC. These patients have a poor prognosis with a significant reduction in tumor-free survival.