It's unclear how the conditions might be connected; experts recommend caution
WebMD News from HealthDay
By Amy Norton
HealthDay Reporter
FRIDAY, March 6, 2015 (HealthDay News) -- Women who survive breast cancer may have a higher-than-average risk of developing thyroid cancer in the next several years, a new study suggests.
Looking at government data on over 700,000 U.S. women treated for breast cancer, researchers found that the women had a higher-than-normal risk of developing thyroid cancer -- particularly within five years of the breast cancer diagnosis.
The study results suggest that breast cancer survivors should have "vigilant screening" for thyroid cancer in the first five years after their diagnosis, said the study's lead author, Dr. Jennifer Hong Kuo, a surgeon at Columbia University Medical Center in New York City.
The study was designed to find an association between breast cancer and the development of thyroid cancer. But, it cannot show whether or not having breast cancer or its treatments caused the increased risk of thyroid cancer.
Kuo said it's too early to give "hard recommendations" on what any thyroid screening for breast cancer survivors should entail.
"At the very least, primary care providers could do a quick thyroid check," Kuo said. That involves feeling the thyroid gland (located in the neck) to look for enlargement or growths -- though thyroid growths are common and usually benign.
Kuo said it might also be a good idea to do an ultrasound scan of the thyroid at least once.
Some cancer specialists urged caution, however.
For one, the findings leave a number of unanswered questions -- including why breast cancer survivors would have a higher risk of thyroid cancer.
"I suspect it would be related to radiation treatment, though it's not clear from the data," said Dr. Subhakar Mutyala, a radiation oncologist at Scott & White Healthcare, in Temple, Texas.
The thyroid gland might in some cases be exposed to radiation treatment for breast cancer.
Kuo said she did find an association between radiation treatment and thyroid cancer, but it did not completely explain the increased risk.
Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, agreed that radiation exposure could be one culprit. But even if that's the case, an issue with this study is that it's based on data ranging from 1973 to 2011, Lichtenfeld said.
source : Breast Cancer Survivors May Have Higher Thyroid Cancer Risk
