Thyroid Cancer

There are over 11,000 new cases of thyroid cancer each year in the US. Females are more likely to have thyroid cancer than men by a ratio of 3:1, and it is more common in people who have been treated with radiation to the head, neck, or chest, most often for benign conditions (although radiation treatment for benign conditions is no longer carried out). Thyroid cancer can occur in any age group, although it is most common after age 30 and its aggressiveness increases significantly in older patients. Rather than causing the whole thyroid gland to enlarge, a cancer usually causes small growths (nodules) within the thyroid. Although as many as 10% of the population will have thyroid nodules, the vast majority are benign. Only approximately 5% of all thyroid nodules are malignant. Nodules are more likely to be cancerous if only one nodule is found rather than several, if a thyroid scan shows that the nodule isn't functioning, if the nodule is solid rather than filled with fluid (cystic), if the nodule is hard, or if the nodule is growing quickly. Thus a nodule that is cold on scan is more likely to be malignant, but the majority of these are benign as well. Thyroid cancers often have a limited ability to take up iodine and produce thyroid hormone, but very rarely they produce enough hormone to cause hyperthyroidism. Symptoms that occur occasionally include hoarseness, neck pain, and enlarged lymph nodes, but it should be noted that the majority of patients present with a nodule on their thyroid that typically does not cause symptoms.