Gene Test Could Predict Thyroid Cancer Risk
Feb. 7 -- FRIDAY, Feb. 6 (HealthDay News) -- Scientists have identified two gene mutations that appear to predict a significant increased risk of developing thyroid cancer.
This finding could lead to early diagnosis and treatment, the researchers said. In 2008, there were 37,340 new cases of thyroid cancer and 1,590 deaths, according to the U.S. National Cancer Institute.
"We found two single nucleotides polymorphisms that confer a risk of thyroid cancer," said lead researcher Dr. Kari Stefansson, CEO of deCODE Genetics, in Reykjavik, Iceland. "When you take the risk of both of them, they have almost six times the risk of thyroid cancer that the average person has," he said.
Stefansson noted the increased risk for thyroid cancer may be due to lower levels of a hormone perhaps regulated by these genes. These mutations are associated with lower levels of thyroid-stimulating hormone, he said.
"This is important in how the cancer develops," Stefansson said. "The thyroid-stimulating hormone is involved in differencing cells in the thyroid. If you have less stimulating hormone, you have less differencing of cells in the thyroid," he said. "We have put our finger on the mechanism whereby these mutations lead to the development of cancer."
The report was published in the Feb. 6 online edition of Nature Genetics.
Stefansson and his colleagues found two mutations that appear to increase the risk of thyroid cancer. These mutations, located on the 9q22 and 14q13 chromosomes, are the first gene variations identified that are associated with the risk of developing thyroid cancer, Stefansson noted.
To find these variations, Stefansson's group looked at the genome of 192 Icelanders with thyroid cancer and 37,196 people in the United States and Spain without the disease.
The researchers found that about 4 percent of people of European descent carry both mutations, increasing their risk 5.7 times for thyroid cancer compared with people without either mutation.
Combined, these mutations may account for about 57 percent of all cases of thyroid cancer. In addition, these variations may signal altered levels of a key hormone produced by the thyroid.
