RECURRENT THYROID-CANCER ROLE OF SURGERY VERSUS RADIOACTIVE IODINE (I-131)

Objective This retrospective study compared treatment and survival of patients with recurrent well-differentiated thyroid cancer that was di agnosed exclusively by I-131 scanning, or by clinical examination. Sum mary Background Data Despite the usual excellent prognosis of differen tiated thyroid cancer, approximately half of patients who develop a re currence eventually succumb to the disease. It has been speculated, bu t not proven, that recurrent disease detected solely by I-131 scanning may offer a better prognosis than recurrences detected clinically and be amendable to I-131 ablative therapy without the addition of surgic al resection. Methods Seventy-four cases of recurrent differentiated t hyroid cancer were identified retrospectively and examined regarding t he location of recurrence, mode of detection of recurrent disease, tre atment of recurrence, and outcome of patients. Using Fischer exact tes ting, outcome results for recurrences detected exclusively by I-131 sc an was compared to that of clinically diagnosed recurrences; among cli nically detected recurrent cases, treatment with surgery only was comp ared to surgery/I-131 ablation. Kaplan-Meier actuarial survival curves were generated for clinically detected recurrent cancer treated by su rgery only and compared to those treated by surgery and I-131 ablation using Gehan-Wilcoxon and log-rank analysis. Results Recurrences locat ed most commonly were regional (53%), followed by local (28%), distant metastasis(13%), and combined locoregional (6%). Among patients whose recurrence was detected scintigraphically, only 9.5% had persistence of disease or were dead of disease compared to 54.0% of patients with clinically detected recurrences. Radioactive iodine ablation in scinti graphically detected recurrences salvaged 18 of 20 patients (90%). Amo ng clinically detected recurrences, surgery alone salvaged 12 of 21 pa tients (57%), whereas the addition of I-131 ablation to surgery salvag ed only 3 of 15 patients (20%, p = 0.05). Conclusion The probability o f dying or living with persistent disease after treatment of recurrent thyroid cancer is less for I-131 detected recurrences compared to cli nically diagnosed recurrences; I-131 ablation without surgery constitu tes adequate therapy for scintigraphically detected recurrences. In cl inically recurrent disease, the addition of I-131 ablation to curative resection does not appear to improve survival.