Distant recurrence is traditionally thought of as metastatic disease. When well-differentiated thyroid cancer metastasizes to distant organs, it most commonly spreads to the lungs, bone or brain.
Un-expectantly, metastatic disease may not be a significant source of symptoms and may be indolent and clinically inapparent for years. This is especially true of small metastatic implants in the lung. Bone and brain metastasis are more commonly symptomatic. Isolated tumors that are causing symptoms may be considered for removal. There are other local therapies that may be considered including traditional radiation therapy and ethanol injection therapy. Traditional chemotherapy is usually considered in advanced cases. While tumors respond on occasion, traditional agents aren’t very effective. A variety of innovative research is on going.