Familial nonmedullary thyroid cancer.

Familial nonmedullary thyroid cancer is more aggressive than sporadic nonmedullary thyroid cancer. It tends to affect younger patients, and the tumors are often multi-focal and bilateral. Histologically, 90% of these tumors are papillary cancers and the remaining are Hürthle cell cancers. We recommend total thyroidectomy to remove all the thyroid tissue, which harbors the genetic defect responsible for the disease (even in low-risk patients) due to the predisposition to develop thyroid cancer and the more aggressive nature of the disease. Careful exploration of the ipsilateral lymph nodes with ipsilateral central neck dissection is encouraged to decrease a high recurrence rate (44%). A complete modified radical neck dissection should be limited to a therapeutic role because there is no clear evidence that this procedure carries any survival benefit. We also recommend that patients receive radioactive iodine ablation post-operatively, including a prophylactic dose (30 mCi) for patients with no evidence of residual uptake on the postoperative iodine 131 whole body scan and in low-risk patients using any of the prognostic scoring systems. Patients should be placed on enough thyroid hormone to suppress thyroid-stimulating hormone (TSH) to approximately 0.1 mL/mL in low-risk patients and to less than 0.1 mL/mL in high-risk patients. Focal metastatic disease in patients with familial nonmedullary thyroid cancer is best dealt with by surgical excision followed by radioactive iodine ablation when appropriate. Redifferentiation therapy has a promising role in patients who have radioactive iodine-resistant tumors. The value of prevention, early detection, and targeted gene therapy once the gene or genes responsible for familial non-medullary thyroid cancer have been identified cannot be overemphasized.