An overview of the management of papillary and follicular thyroid carcinoma.

Long-term survival rate for papillary and follicular carcinoma is more than 90%, but this varies considerably among subsets of patients. About 30% of patients, however, develop tumor recurrence, depending on the initial therapy. Two-thirds of the recurrences occur within the first decade after therapy, but the others may appear years later. We found that among patients with recurrent cancer, 30% could not be fully eradicated and another 15% died of disease. Tumor recurred outside the neck in 21% of our patients, most commonly in the lungs (63%), which resulted in death in about half the patients. Mortality rates are lower when recurrences are detected early by radioiodine scans rather than by clinical signs. We believe that the best treatment for most patients with differentiated thyroid carcinoma is near-total thyroidectomy followed by 131I ablation of the thyroid remnant, which in our experience reduces the recurrence rate, improves survival and facilitates follow-up. A long delay in initiating this therapy has an adverse and independent effect on prognosis, more than doubling the 30-year cancer mortality rate. If only partial lobectomy has been performed, it is best to consider completion thyroidectomy for lesions 1 cm or larger because of the high rate of residual carcinoma in the contralateral lobe. Completion thyroidectomy and 131I whole-body scanning allows for the diagnosis and treatment of unrecognized carcinoma and when performed early, results in significantly fewer lymph node and hematogenous recurrences and enhances survival. A large and growing number of studies demonstrates decreased recurrence of papillary carcinoma and decreased disease-specific mortality attributable to 131I therapy. On the basis of our observations and other studies, we believe that an aggressive approach to initial management and follow-up may render nearly 90% of the patients permanently free of disease. Periodic follow-up should be done with whole-body scanning and serum thyroglobulin (Tg) measurements, performed either during thyroid hormone withdrawal or by recombinant human thyrotropin (TSH)-stimulated scanning and Tg measurement. A scheme for follow-up management is presented.