Thyroid cancer rates double in a decade

Asking about radiation exposure and family history could provide clues as to who is vulnerable to this disease.

By Susan J. Landers, AMNews staff. Nov. 13, 2006.

Washington -- Thyroid cancer rates have doubled in the past 10 years, and the increase has been the greatest among women. But why this jump is happening is unknown.

The rate of newly diagnosed thyroid cancer has surpassed the rate of ovarian cancers found, said Steven Libutti, MD, chief of the National Cancer Institute's tumor angiogenesis section. "I think it has moved up to No. 7" in the most common cancers among women, he said. "Ten years ago, it did not even make the top 10 list."

Theories abound as to why. They range from radiation exposure -- either via the environment or as a result of its use as a treatment tool -- to physicians' sharpened detection skills. Recent research also suggests that a female sex hormone, most notably estradiol, could play a role.

Physicians are urged to be vigilant because, if detected early and treated optimally, thyroid cancer has an excellent cure rate, Dr. Libutti said.

The "Annual Report to the Nation on the Status of Cancer" released in September tracked this cancer's increase among women since 1981 and found that it rose by 2.2% per year until 1993, then began a 4.6% annual increase that lasted until 2000. From 2000 to 2003, this rate nearly doubled again to 9.1% per year.

Rates among men have also been escalating, noted Ahmedin Jemal, PhD, the American Cancer Society's strategic director for cancer occurrence. In 1990, incidence rates for men were 2.9 thyroid cancers for every 100,000 people. By 2003, the rate was 4.6 cases per 100,000, a nearly 50% boost. During the same period the rate for women went up by 75%, he said.