Researchers at Ohio State recently found they can detect whether thyroid cancer will recur in patients by testing their blood.
The study focused on thyroglobulin levels which, according to an OSU press release, is a protein made by thyroid cancer cells. Thyrogen, a new drug, tests and measures amounts of thyroglobulin in the body when injected into the body and does not allow for negative side effects during the testing, according to the release.
The study shows that even if a person has a low or undetectable amount of thyroglobulin cells, patients might still have recurrence years later. The research completed at OSU found that even in patients with low thyroglobulin levels, two-to-five percent have experienced reoccurring thyroid cancer after three to five years.
Richard Kloos, an author of the study and associate professor of internal medicine and radiology at OSU, said this study is important because in the past the cancer would be larger and much more advanced before it was found, but this new data shows doctors can find these tumors earlier.
Darrell Ward, associate director of Ohio State University Medical Center communications, said this method is important because it is a better way to test for thyroid cancer.
Ward said the typical treatment for thyroid cancer is surgically removing the thyroid gland, then ingesting radioactive iodine to kill any remaining cancer cells. To make up for the lost thyroid, patients must take a synthetic thyroid hormone, Ward said.
“These people no longer have thyroids and are dependent on these synthetic hormones,” Kloos said. “These hormones are required for life.”
After surgery, a patient’s thyroglobulin levels should be zero. If it is not and levels do not decline over time after surgery, their presence signals a possible return of the disease.
Before 1998, patients were required to stop taking the synthetic hormone before testing, according to the release. Most patients went through a negative withdrawal when they stopped the taking the much-needed drug. Some side effects include fatigue, weight gain, depression and other symptoms, Kloos said.
“These findings provide an opportunity for testing without people becoming hyperthyroid,” said Ward. “Being hyperthyroid is very uncomfortable and hard to live with.”
Ileana Hernandez was diagnosed with thyroid cancer in January 2000. She said she beat cancer by having her thyroid surgically removed and used radioactive iodine a couple months later to kill any remaining cells.
“About every four to six months I have my hormones tested to make sure there are still not any cancer cells in my body,” Hernandez said.
Hernandez said she is tested through blood work, not by the Thyrogen injection.
“I don’t know what my chances are of recurrence. They don’t tell me,” she said. “But, yeah, I would like to know if I have a chance of ever getting cancer again and what those chances are.”
OSU’s study involved 107 patients, 88 women and 19 men. After surgery patients were injected with Thyrogen and their levels were tested between January 1999 and March 2001. Based on their thyroglobulin readings, the patients were divided into three groups: levels below 0.5, levels between 0.6 and 2.0, and levels greater than 2.0. After at least three years, patients with thyroglobulin levels greater than 2.0 had 80 percent recurrence and patients with thyroglobulin levels below 0.5 had 2 percent recurrence.
“I think of this testing as a blessing because we know what we’re looking for,” Kloos said.
The release said of all 330,000 living Americans treated for thyroid cancer, approximately 20 percent are likely to have the disease recur in their future.
Kloos said everyone who has had thyroid cancer should undergo persistent testing since recurrence can happen any time, even after the cancer has been removed.
“The technology we use is not perfect. It can’t detect a single cell,” Kloos said. “But the results of this study are helping us find cancer early which is good for everyone.”
