Dr. Sheldon Rubenfeld Board Certified in Internal Medicine and in Endocrinology, Diabetes, and Metabolism

Anaplastic Thyroid Cancer

An anaplastic thyroid cancer is an undifferentiated tumor arising from thyroid follicular cells. When cells from a thyroid cancer look similar to normal thyroid follicular cells, the cancer is described as differentiated. When the cells from a thyroid cancer appear completely different from normal thyroid follicular cells, the cancer is referred to as undifferentiated (anaplastic). Accounting for approximately 2 to 5% of all thyroid cancers, anaplastic cancers occur primarily among women sixty-five years and older, although 10% of the patients are younger than fifty, and 30 to 40% are men.

Many physicians speculate that undifferentiated thyroid cancers arise from pre-existing or co-existing differentiated (papillary or follicular) thyroid cancers. Although small differentiated thyroid cancers are found frequently at autopsy and appear to be of little biological significance, large and aggressive differentiated thyroid cancers have the potential to become undifferentiated thyroid cancers if they are not adequately treated.

Anaplastic thyroid cancer behaves very aggressively. The prognosis is, unfortunately, very poor; most patients do not live for more than one year after they are diagnosed. Ordinarily, physicians do not recommend aggressive surgery, and some patients may not have any surgery at all since most anaplastic thyroid cancers are incurable at the time they are found. When surgery is done, surgeons often do what they can to prevent death caused by airway obstruction. External-beam radiation and chemotherapy are occasionally effective for a short period of time.