Secondary thyroid cancers are more deadly, study finds (w/VIDEO)
March 14, 2014 | by Hiu Chung So
Although thyroid tumors are rarely life-threatening, scientists have found that patients with secondary thyroid cancer (in other words, thyroid cancer that develops after the person has survived another cancer) are more likely to die of the disease compared to those whose thyroid cancer was as their primary — or first — cancer. The findings were published online in advance of print recently in the journal Cancer. In the study, the researchers analyzed more than 41,000 cases of thyroid cancer among teens and young adults (up to 39 years old). Approximately 3 percent of those cases were secondary thyroid cancers. After controlling for other factors — including demographics, stage of cancer upon diagnosis and how it was treated — the authors found that people with secondary thyroid cancers are 6.6 times more likely to die of the disease compared to those with primary thyroid cancers. That statistic may sound alarming, but John Yim, M.D., associate professor and surgeon in City of Hope's Division of Surgical Oncology, said that, overall, thyroid cancer prognoses are very good."The survival for most thyroid cancers is 98 percent; in this case [of secondary thyroid cancers], the survival is about 95 percent," Yim said in the video above. But because the difference is statistically significant, it warrants further study, Yim said. Such study would include an analysis of the diagnoses and treatments received by the secondary thyroid cancer patients, and whether they were tied to deadlier or harder-to-treat thyroid cancers later in life. For example, Yim said, the thyroid gland is particularly susceptible to radiation, so patients who have had their head or neck areas irradiated as part of a prior cancer treatment may be more prone to developing thyroid cancer. Additionally, Yim pointed out, the new study also found that Hispanics are more likely to die from secondary thyroid cancers compared to other ethnic groups. He concurs with the authors' opinion that "whether this is a direct consequence of previous cancer treatment, biological or environmental factors, or disparity in access to care is an area that needs further investigation." According to the American Cancer Society, there will be more than 62,000 new cases of thyroid cancer in the United States and approximately 1,890 Americans will die from the disease this year. *** Learn more about thyroid cancer.